WO2012089858A1 - Device for protecting delicate surfaces of electronic apparatuses - Google Patents

Abstract

Device for protecting delicate surfaces of electronic apparatuses, which device is based on a laminar and flexible cover which slides along a guide system with an outline which is not exclusively straight. Said device which is included in particular apparatuses protects the most delicate surfaces thereof, for example the display screens of mobile telephones, notebooks, electronic books, computers, etc., against dust, scoring, scratches, radiation, splashes, etc. Said device also cleans and polishes the protected surface and, in turn, is self-cleaning and allows a high degree of personalization and decoration of the apparatus to which said device is applied.

Description

 DEVICE FOR THE PROTECTION OF DELICATE SURFACES OF ELECTRONIC DEVICES

OBJECT OF THE INVENTION

 The present invention, device for the protection of delicate surfaces of electronic devices, refers to a protective device based on a laminar and flexible cover that slides along a guiding system of not exclusively straight path. This device, incorporated in certain devices, protects against dust, scratches, scratches, radiations, splashes, etc. its more delicate surfaces such as, for example, mobile phone display screens, agendas, e-books, computers, etc. Said device also cleans and polishes the protected surface and, in turn, is self-cleaning and allows a high degree of customization and decoration of the appliance to which it is applied.

 It is, therefore, a device that can be used preferably in the field of electronic devices, although it can also be used in other products that have a delicate surface, and especially in heavy-duty notebooks with large display screens.

DESCRIPTION OF THE STATE OF THE TECHNIQUE

The importance and influence that electronic devices have on our lifestyle, grows at a dizzying pace, it is currently very difficult to find in a country economically developed a person who does not use an electronic device such as television, computer, video game console, e-book, mobile phone, etc. However, it is easy to find people who frequently use all of them. Thanks to the advances in miniaturization, many portable devices are launched, even pocket-sized, with innumerable built-in functions that, in order to be handled, require the exchange of information with the user through a display screen and / or a keyboard. There is also a clear and progressive trend to avoid or reduce in the design of such devices the mechanical elements of data entry such as keypads and keyboards, replacing them with touch screens that have the great advantage of allowing an infinity of introduction modes of data controlled by software, so that they can easily adapt their form and content to the context, resulting much more intuitive.

 Probably, regarding the number of hours of interaction, the most important object for the technological society is the display screen, above any other object, person or animal. Therefore, it can be stated without possibility of mistake that getting this interaction to take place in conditions of maximum visual comfort is a technical problem to be taken into account. Scratches, fingerprints, impregnations of sweat or body fat, so frequent in portable electronic devices, significantly reduce visual comfort, especially in high ambient light conditions.

 The use of technical means for protection against scratching of delicate surfaces in electronic devices is highly developed, especially in the field of mobile telephony where numerous patents and utility models have arisen because they are massively and intensively used devices They are usually stored in pockets, briefcases or bags along with other everyday objects that can damage them such as keys, coins, pens, etc. However, the present invention manages to surpass all previous solutions mainly due to its ease of use and opening speed, its extremely low thickness and low weight, its durability, its high aesthetic qualities and, additionally, its surface cleaning function delicate and its very low production cost.

The systems that currently exist for the protection of electronic devices or their most delicate parts can be grouped into three modalities. A first mode would comprise those cases or cases that must be completely separated to be able to use the device, such as, for example, Spanish utility model number ES1 063259, which describes a quilted cloth bag for containing and protecting mobile phones, calculators, etc. Another document is the Spanish utility model number ES1036326, which describes a rigid case attached to the trouser belt that allows the electronic device to be inserted and extracted by opening a flap. These devices protect but do not clean and have the disadvantage that they considerably increase the volume of the device and prevent its fast and fluid use, which currently, and especially in the case of mobile phones, can be considered a harm, because the pace of life and communications leads to the need for increasingly rapid interactions with electronic devices. On the other hand, bag-type systems generate the additional annoyance of having to deal with the bag, once separated, each time the appliance is used.

A second embodiment would comprise those protective devices that, in order to allow access to the delicate surface, require the sliding, turning or other similar movement of a protective cover without it becoming detached from the apparatus. Examples of this type of protector are described in the Chinese patent application number CN201210699Y, which describes a rigid protection system based on two sliding covers in opposite directions located on the screen and keyboard of a mobile telephone. Another example of this type of protector is the French patent application number FR2760933A1, which describes a hinged cover that covers the entire front part of a mobile telephone. In protective devices that use this mode, the disadvantage usually arises that, once open, there remain protruding parts of the apparatus that occupy a lot of space and are very vulnerable to shocks and accidental forces. In addition, existing models in the market based on this system do not clean the surface. A third embodiment comprises those protective devices that allow the device to be used without the need to remove them, even in part, such as, for example, the Spanish utility model number ES1053442, which describes a sheath of transparent plastic material of very little thickness that fits a mobile phone by thermo-retractable effect and is wrapped without the possibility of removing it unless it breaks. Also, the patent application number US20100048267A1 is applicable especially to screens of tactile type and comprises a housing housing of telephone that incorporates a protective lens that remains fixed on top of the touch screen of said telephone. These devices considerably reduce the sharpness of visual perception by the simple fact of adding a layer through which the device must be seen, which can be significantly aggravated when the protective device itself is scratched or condensations or dirt appear on the interface. On the other hand, devices of this type also do not clean the surface they protect or clean themselves. In view of the above, there are different documents in the state of the art that describe devices intended to alleviate different problems but, or do not do so with complete efficiency or generate, by their mere presence, other problems that did not previously exist. It is therefore an object of the present invention a protective device that solves the problems existing in the state of the art in a satisfactory manner.

DESCRIPTION OF THE INVENTION An object of the present invention is a protective device for delicate surfaces of electronic devices, comprising a fixed, rigid and integral part to the electronic device that has a guiding system or guiding means of not exclusively straight path, which discloses at least one curve, with at least two opposed guiding elements, and a sliding mobile part along the guiding system comprising a continuous sheet, confined between said guiding elements and having a degree of flexibility that allows bending of the same without having been previously shaped, so that the mobile part moves between a first position in which the delicate surface is covered by the sheet, facing the lower surface of the sheet, and a second position in which the delicate surface is not hidden behind the sheet, hidden in the fixed part, and said sheet always comprising gone in the fixed part of the device.

 The present invention allows to solve the problems posed in the state of the art since it has protection means that allow to protect electronic devices against dust, scratching, scratches, radiations, splashes, etc., in particular their surfaces more delicate, such as, for example, the display screens of mobile phones, diaries, e-books, computers, etc. Said device can also clean and polish the protected surface and, in turn, be self-cleaning and allow a high degree of personalization and decoration of the electronic device to which it is applied.

 To facilitate the handling of the sheet, it incorporates a linear stiffener element integral with each of its edges transverse to the direction of the sliding that are not confined by the elements of the guidance system.

Likewise, the sheet has on its lower surface a cleaning strip, for example, of polymeric micro-fiber felt, self-adhesive and removable, placed in a place such that by bringing the sheet from its fully closed position to its fully open position and vice versa, said cleaning strip sweeps the entire delicate surface by removing dirt from it. The thickness of the cleaning strip is equivalent to the height between the guides of the first section of the guidance system and the delicate surface.

 In order to reduce adhesion by wetting as well as adhesion by electrostatic forces, the sheet has a textured surface by a high density of micro-slits, preferably of a width and depth of less than 25 microns.

 This sheet is made with materials with ductile fracture for the expected service conditions and that meet the condition expressed by the formula:

300> (E, / 3-σ _β )> 1

 And among them, preferably the materials that meet the formula are selected:

50> (E, / 3-σ _β )> 6

On the other hand, and to achieve the appropriate degree of rigidity-flexibility the sheet must be made with materials and thicknesses that meet in each of the points of said sheet that have to be subjected to bending, the following inequality:

R> (Efdsm) O _e

 And among them, the following realizations are preferable:

R> 4- (E, -d _sm ) / σ _β

It is possible to improve the degree of rigidity-flexibility of the sheet by incorporating therein a multiplicity of grooves arranged in the same direction as the generatrices of the surface resulting from the bending imposed on the sheet by the guiding system, grooves that they are therefore transverse to the guiding elements through which the sheet slides. An alternative to improve the degree of rigidity-flexibility is to use a sheet that presents a multiplicity of bands alternating materials of greater rigidity with materials of lower rigidity. As in the previous case, said bands are arranged in the same direction as the generatrices of the surface that results from the bending imposed on the sheet by the guidance system.

 The device object of the present invention has openings in the guiding elements to allow the introduction and removal of the protective sheet without the need to use tools. Preferably the openings are located at the beginning of the path, where the closing point of the sheet is located.

 The device also has a means of blocking the sliding of the protective sheet consisting of a point narrowing of the distance between the two opposite guides that border the delicate surface, so that the separation between the guides at the point of narrowing is slightly smaller than the stiffener length mentioned above. The reduction of the width of passage forces to realize a high force on the stiffener so that, by deformation, it overcomes the obstacle. The narrowing is calculated, depending on the intervening materials, so that the force necessary to overcome it is greater than any foreseeable force that could accidentally open the device but without the stresses produced by the opening force exceeding the elastic limit of the materials. The point narrowing is preferably located very close to the closing point of the sheet.

 Also, the device can have a cleaning strip, for example, of polymeric micro-fiber felt, self-adhesive and removable, placed in a place of the moving part such that by bringing the protective sheet from its fully closed position to its fully open position and vice versa, said cleaning strip sweeps the entire visible surface of the protective sheet eliminating dirt from it. The cleaning strip is preferably located very close to the maximum opening point of the protective sheet.

 The device can incorporate at least one rotating roller in the path of the sheet as a means to reduce friction and as a means of automating the sliding of the sheet when, at least said roller, receives a torque from a source of motive power as, for example, an electric motor.

Said device can be part of the electronic device or, on the contrary, it can be an additional and independent accessory element of the electronic device without affecting the normal operation of said electronic device. The preferred way of fixing the guidance system to the electronic device is by simple coupling by pressure, without the need for tools. In view of the main characteristics of the present invention, it solves the problems posed in the state of the art since the device allows an extremely fast opening because the protective sheet generates very weak friction forces and has very little mass, Therefore, its opposition to acceleration is negligible in relation to the motive forces that can be applied manually or mechanically. On the other hand, in the invention described herein, in order to leave the delicate surface accessible to the user, it is not necessary to separate the protective sheet from the apparatus, thereby avoiding the loss or inconvenience of having to take charge of an independent object. additional.

 On the other hand, when making the action on the sheet that leaves the delicate surface accessible, there are no outstanding elements or the dimensions of the apparatus are altered, therefore, it does not present difficulties of use derived from the increase in size or vulnerability to crashes or forces accidental The sheet, when in closed position, has most of its surface covering the delicate surface, for example, the display screen. When the sheet is in open position, it will have most of its surface in another position where it does not obstruct the use, as for example, the opposite side of the same device, leaving the screen completely accessible. The retraction of the sheet is possible thanks to the adequate degree of flexibility-stiffness of said sheet and to the shape and arrangement of the guiding means which, for example, have a section on the face of the apparatus having the screen, another section in the opposite face of said apparatus and a semicircular section that connects the previous ones allowing the sheet to move changing the direction of its trajectory. Since the said sheet slides at all times without separating from the apparatus and even, in some sections, can be completely hidden and protected under the housing, it will not have to support other forces than the own motive power and its corresponding reactions. That is the reason why it is a highly robust and durable system despite incorporating extremely thin protective sheets.

The device object of the present invention comprises a sheet that slides along guides and covers the delicate surface of the apparatus protecting it from scratches. Depending on its material and its surface treatment, said sheet may allow the delicate surface to be seen without removing the sheet, but there is always the possibility of removing it when desired. Therefore, problems of lack of sharpness in vision are completely avoided. On the other hand, the movement itself The sheet allows the cleaning of the delicate surface and, at the same time, that of the sheet itself, so that the optical conditions resulting from the application of this invention improve those of any other invention belonging to the current state of the art.

 In view of the foregoing, it is convenient to mention the advantages of the present invention with respect to the solutions existing in the state of the art:

 one . Its weight is negligible in relation to that of the protected apparatus. For example, the weight gain suffered by a mobile phone with a touch screen protected by this device may be less than 0.5 grams.

 2. In the device claimed the thickness and volume are negligible in relation to those of the protected apparatus. For example, the thickness of the protective sheet used for a touch screen mobile phone of 12.9 millimeters in total thickness may be less than 0.05 millimeters. And the thickness of the complete system, i.e. sheet and guiding means, can be less than 1.3 millimeters.

3. As a consequence of the first two advantages mentioned, the invention is respectful with the environment because it requires little energy for its manufacture and transport. It is also easy to recycle, since it consists of few parts and these can be made with 100% recyclable materials. For the same reasons, the C0 ₂ emissions and contaminating compounds during their life cycle can be significantly smaller than with most proprietary systems of the state of the art.

 4. The drive speed can be very high. For example, the complete sliding of the sheet that protects the screen of a 50 mm x 95 mm mobile phone can be performed manually in less than 0.2 seconds.

 5. The device claimed in this document has the ability to clean the surface that protects and even polishes it. What is an important advantage because it always stays clean and prevents the user, before a large accumulation of dirt, is forced to clean it urgently with the materials at hand such as paper napkins, the sleeve of the shirt, handkerchiefs, etc. that in some cases may be unsuitable and end up damaging the surface, especially if it is made of plastic material.

6. The claimed device can clean itself when it is actuated. 7. The device can allow the use and visibility of the surface it protects without being removed. For example, in the case of its application to touch screens of mobile phones (capacitive or resistive), it can be used as material constituting the protective sheets, completely transparent plastics or with a layer of metal deposits that, under normal conditions with the phone off , they generate a mirror effect that prevents the visibility of the screen but, when the screen is illuminated, they let it see clearly. This, notwithstanding that the sheet can be removed, by sliding, when the user sees fit.

 8. The device allows a high degree of decorative variety because the sheets can have many aspects through the use of different materials and production techniques such as opaque, transparent, translucent sheets; with metallic layers in colors such as gold, silver, bronze, iridescent, etc., sheets of color in mass; sheets printed by different techniques; in matt finishes, gloss, textures, etc., they can even be luminescent, phosphorescent, etc. You can also use white sheets of a material compatible with the most widespread printers on the market so that the user or a specialized supplier can print them with a personalized image such as the user's own photograph, a family member's photograph, his or her photograph. favorite landscape, your pet's, etc.

 9. The protective sheet can be removed very easily by the user in less than 1 second, and inserted in 2 or 3 seconds without the need to disassemble the device or make intermediate operations (estimated times for mobile phones).

 10. The production cost of the claimed device is extremely low, representing, for example, for mobile phones, normally between 0.10% and 1% of the total production cost of the apparatus. Depending on this cost of the material and performance of the sheet that can be very varied, such as, for example, simple white sheets, sheets with treatments resistant to scratches, with polarizing effect of light, phosphorescent, non-stick, antistatic, metallic, etc.

DESCRIPTION OF THE FIGURES The figures that accompany the present invention and that are explanatory but not limiting serve to interpret and understand the present invention are detailed below. The figures are:

 Figure 1: Shows a perspective of an embodiment of the invention in which the guidance system forms an inseparable part of the electronic device.

 Figure 2: Shows a section of an electronic device having the protection device incorporated in an inseparable manner.

 Figure 3: Shows a perspective of an embodiment of the guidance system in which there are no formal differences between some sections and others.

Figure 4: Shows a perspective in which the protective device is seen as a removable accessory and, therefore, some of the elements used for the guidance are not specific to the electronic device.

 Figure 5: Shows a section / perspective of an electronic device with protection device of the delicate surface, where the preferred way of distributing the confinement clearances for the good sliding of the protective sheet can be seen.

 Figure 6: Shows a perspective of an example of tracing the guidance system formed by tangentially linked curves.

 Figure 7: Shows a perspective of an example of tracing the guidance system in which concave sections are alternated with convex sections by inflection points.

 Figure 8: Shows a perspective that exemplifies the possibility of derailment of the sheet due to excessive flexing of the free edge.

 Figure 9: Shows a perspective where you can see the damage that a very thin sheet can suffer in the free edge (nicks and folds) when a stiffener has not been placed.

 Figure 10: Shows a perspective that exemplifies the possibility of dents and tears appearing in the area near the unstiffened free edge of a very thin sheet, when the driving force is applied on this edge.

Figure 11: Shows a perspective of an example of cleaning strip or self-cleaning self-adhesive.

Figure 12: It shows a section of a protective sheet on a delicate surface where you can see micro-slits, the air film that traps the micro-slits, and how said air film separates the sheet from the adherent surface.

 Figure 13: Shows a section of a motorized embodiment in which rolls or cylinders for transmitting the driving force to the sheet are seen.

Figure 14: Shows a section exemplifying a protective sheet with grooves and uniform material.

 Figure 15: Shows a section exemplifying a protective sheet with grooves and non-uniform material.

 Figure 16: Shows a section exemplifying a sheet formed with alternating stripes of more rigid material with less rigid material.

 Figure 17: Shows a perspective of how the grooves of the protective sheet coincide with generatrices of the curved surface generated by the action of the guidance system.

 Figure 18: Shows a perspective exemplifying a form of extraction and insertion of the protective sheet.

PREFERRED EMBODIMENT FORM Next, the present invention will be described with reference to the different figures.

The fixed part of the device, which includes the means or guidance system (1), can refer either to the electronic device itself that includes in its construction said means or guidance system, or it can refer to an element that houses the electronic device such as a sleeve or similar. Likewise, the means or guidance system (1) which restricts the displacement of the mobile element to a single predetermined path in two directions may vary the characteristics of the guiding elements, which make up the guiding means, along its route, such as throat width, throat depth, material, shape, etc. Also, due to constructive constraints, it may be that the guidance is not made with specially added elements for that purpose, but that necessarily constituent parts of the device are used so that, properly designed and ordered, prevent the movement of the protective sheet (2) in all directions except for the planned displacement. These parts can be, for example, the housing (3), the screen (4), the battery (5), the internal frame of the device (6), etc. Rollers or revolving cylinders (35) can also be used at some points along the path to reduce friction with the sheet (2), preferably at those points where the slip changes direction or direction.

 The guiding means or system (2) normally have several differentiable sections, the first section (7) starts with a pair of guides or grooves (7) that run along two opposite edges of the delicate surface (4), located slightly by above and equidistant to said surface. If the delicate surface exceeds 50% of the total surface of the face of the appliance where it is located or, even if not, if there is no non-working surface of the same dimensions as the delicate surface on the face of the appliance where the delicate surface is located , then there is no possibility that the protective sheet (2), when removed from the delicate surface, is housed in the same face of the apparatus. Consequently, the guidance system (1) has to guide the sheet (2), through a second section with the appropriate curvature (8), to a place where it can remain without obstructing the functioning of the device and without protruding from it. In this place of retraction of the sheet, the third section of the guidance system (9) is located. Although in some particular embodiments it can happen that there are no appreciable formal differences between some sections and others (10).

The guiding mode in the first section through the abovementioned grooves (7) obviously keeps the protective sheet (2) visible and is suitable so that, once said protective sheet (2) is slid, the delicate surface is completely exposed (4) . However, in the parts of the path that do not coincide with the delicate surface (4), it is much more convenient, although not essential, for the protective sheet (2) to slide out of reach of the user, preferably under the housing of the apparatus for avoid involuntary actions on it that can cause derails (21), folds (22) or blockages of said sheet (2). And in that case the guidance can be carried out by means of the arrangement of confinement surfaces (11) which, as already mentioned above, can be the delimiting surfaces proper to necessarily constituent parts of the apparatus such as the internal face of the housing (3) , the envelope of the battery (5), etc. or, on the other hand, additional surface elements (12) can be arranged with no other function than that of confining and directing the sheet (2). However, it is preferable that the guide system (1) avoid, by means of the appropriate design, the intense friction of the surface of the sheet (2) because it can be to accelerate the deterioration of the same one and because they can appear forces of adherence and of friction that prejudice the sliding. This can be achieved by making the areas of the guidance system (1) through which the edges of the sheet (2) run parallel to the direction of movement are slightly highlighted (13) with respect to the rest of the surface of the guidance system (14), which will reduce or eliminate the contact pressure of the visible surface of the sheet (15) and the rest of its surface, except for the edges of said sheet (2) that are oriented in the direction of the slide (16). ), where the pressure will increase.

 As said above, rollers or cylinders (35) can also be used to reduce friction, especially at points where the circulation of the sheet changes direction or direction.

The layout of the guidance system can be composed of a simple curve (17) or several tangentially linked curves (18) or alternating curves and straight stretches (19) and even have inflection points (20) in which the route of the sheet passes from concave to convex, with the condition that its curvatures are proportioned to the degree of flexibility-rigidity of the protective sheet.

 In case of having formed the path with sections of different curvature, the sheet (2) will modify its own shape adapting to the shape imposed by the guidance system (1) while moving along its path. At least, in a section of the route, when sliding along said section, the surface of the sheet (2) is transformed into a regulated surface, developed and not flat, without having been shaped before its insertion in the guidance system (1). ).

 The sheets (2) must have rigidity to transmit the motive forces and other acting forces through their mass without unduly deforming and, at the same time, they must have the flexibility to accept the curvatures imposed by the guidance system (1), that is, the sheet must have an "adequate degree of flexibility-rigidity".

On the other hand, any material can be used for the guidance system (1) that resists the forces exerted by the sheet (2) and the rest of forces that will act on it without deforming excessively and at the same time having a coefficient of friction with the material of the sheet (2) that does not generate friction forces incompatible with the operation of the system, being able to use very diverse materials such as metals, thermoplastic plastics, thermosetting plastics, wood, etc. However, if for the chosen materials, due to their conditions of curvature, rigidity, roughness and / or thickness of sheet (2), friction forces excessively high in relation to the motive force and / or excessive noise level appear in the contact zones between the guidance system (1) and the sheet (2), such a drawback can be overcome by adding coatings to the sheet (2) or the guide system (1) or both (1, 2), which reduce the coefficient of friction such as polytetrafluoroethylene, perfluoroalkoxide, floured ethylene propylene or any other compound with similar properties. According to the characteristics of the particular embodiment, it is also possible to incorporate wheels, lubricants or any other means that serves to reduce friction.

Due to the extreme thinness desirable in the sheets, in certain determined cases, the edges of the sheets that are not protected or sufficiently confined, may suffer problems such as:

 • Derailment of the sheet. When applying the manual motive force or any other force on a not sufficiently confined edge, its bending can be caused accidentally and, then, the sheet can derail by mere shortening of the distance between the ends of said edge. (twenty-one )

• Folds or nicks in the edge. If the operation of the device requires, for example to be closed, that one edge of the sheet abuts against a rigid element, then, that edge may suffer during the cycles of operation folds and / or nicks. (22)

 • Dents and tears. Especially in cases where the driving force is manually transmitted on an unconfined edge, dents (23) and even tears (24) may appear on the sheet due to the high concentration of tensions caused by the application of the fingers.

To avoid the mentioned problems, the edge susceptible to being affected is stiffened or reinforced. This reinforcement can be carried out by a local modification of the material of the sheet without increasing its thickness or by adding a nervature (25) of the same material of the sheet or other different material. This second option being the most viable in extremely thin sheets. Depending on the strength required, the reinforcement (25) made can penetrate into the guide grooves (1) or not. If the stiffener (25) penetrates, more resistance but less flexibility will be obtained, which will increase the minimum radius of curvature. If the stiffener (25) does not penetrate, there will be less strength but more flexibility. Although cleaning is important in any case, there are some specific applications in which it acquires special relevance to achieve optimum visual comfort, such as touch screens for mobile phones, which must withstand the action of the user's fingers, dust and humidity and the impregnations of sweat, makeup and body fat that can occur when the phone is in contact with the skin.

 In the present invention, the cleaning of the protected surface is carried out by incorporating a cleaning strip (26) on the back of the protective sheet (2). Located said strip (26) in a part such that when the sheet (2) is slid from its fully closed position to its fully open position and vice versa, the cleaning strip (26) performs a sweep of the entire protected surface (4) . Normally, this condition of location is fulfilled by an unconfined edge of the protective sheet (2) in which, moreover, as explained in the previous section, a stiffener (25) is located which allows the manual motive power to be distributed throughout the cleaning strip (26) exerting an almost uniform pressure on the surface to be cleaned. The cleaning strip (26) can be formed by simply cutting it to the appropriate size, for example, of a foamed plastic material such as polyurethane, or of a natural or artificial fabric, or preferably of a nonwoven cleaning cloth or felt constituted by polymer fibers. Some of these materials are formed by very small diameter fibers up to 0.3μηι that have a very fine abrasive effect on the protected surface and therefore, if the applied pressure on the stiffener is adequate, they produce a brilliant polish at the same time who clean it However, it should be noted that the capacity to retain dirt particles of the cleaning strip (26) is limited, so it has to be washed with some regularity and / or be replaced. Although it is possible to wash the cleaning strip (26) when the user considers it necessary, the present invention provides that the cleaning strip (26) is easily replaceable thanks to the disposition of a removable adhesive (27) on one of the faces of said cleaning strip (26). As usual in an infinity of self-adhesive objects, the adhesive of the cleaning strip (26) is covered by a protective strip (28) that is removed just before its application.

The present invention also has a self-cleaning element of the protective sheet (2) itself by means of a second cleaning strip (29), also self-adhesive and removable, which is fixed in a suitable place of the guidance system (1) , so that by sliding the protective sheet (2) from its fully closed position to its fully open position and vice versa, the second cleaning strip (29) sweeps the obverse or visible surface of the protective sheet (1). The choice of material and characteristics of this second cleaning strip (29) is made according to the requirements of the protective sheet (2), so that in some particular embodiments both stripes (26, 29) may coincide in shape and material and in others, be different. Said second cleaning strip (29) also has the function of preventing bending of the protective sheet in a plane perpendicular to the direction of sliding of said sheet because it helps its confinement without attacking or scratching it. Likewise, the cleaning effect of this second strip (29) is enhanced by manually pressing on it at the same time that the protective sheet (2) slides with traction effect.

In order to avoid the involuntary sliding of the protective sheet and to expose the delicate surface exposing it to scratches and erosions caused by other objects such as keys, coins, etc., the present invention contemplates the incorporation of a blocking mechanism of the protective sheet (2) which can have several different forms of embodiment:

 one . Blocking by pressure. The guide system suffers in a very close to the point of closure of the sheet a point narrowing of the distance between the two slots or opposite guides that border the delicate surface, preferably materialized by respective shoulders (30) in said guides, in such a way that said distance is slightly smaller than the length of the stiffener (25) disposed at the unconfined edge of the sheet (2). The aforementioned reduction of the width of passage forces to make a high force on the stiffener (25) so that, by deformation, overcome the obstacle. The constriction (30) is calculated, depending on the intervening materials so that the force necessary to overcome it is greater than the frictional force that friction can produce against the walls of the bag or pocket and, therefore, create a blockage by Pressure.

2. Magnetic lock. The device is provided with two magnets, one located in the stiffener (25) of the non-confined edge and the other at the point where said stiffener abuts for closure. The magnets are oriented so that their opposite poles come into contact creating a magnetic block which requires the application of a higher force than can be caused by friction with the walls of the bag or pocket. They can be used instead of two magnets, two elements that have a mutual magnetic attraction even if one of them does not generate its own magnetic field. 3. Blocking by friction. The thickness of the protective sheet (2) has been calculated so that the frictional force generated by the friction of the sheet against the guide system (1) is greater than the frictional force generated by the friction of the sheet with the walls of the bag or pocket, which causes a blockage by friction

Some embodiments of the invention can incorporate extremely thin sheets (2) in which the adhesion forces between the sheet and the surface that it protects (4), especially when they are wet, take on excessive relevance in relation to the degree of flexibility-stiffness of the sheet. These forces of adherence, by opposing the driving force can cause braking and inadmissible deformations in the sheet when the stresses are compression or simply the braking of the sheet when the stresses are traction. This adhesion may be due mainly to the electrostatic forces that are created by intimate contact between the sheet and the protected surface, or the presence of water (33), fats, etc. at the interface between the sheet and the protected surface. To solve this problem it is possible to adopt individually or jointly any of the following measures:

 - use materials for the protective sheet (2) and the delicate surface (4) next in the triboelectric series,

- use sheets that have, in those parts of its surface susceptible to suffer the problems of adhesion, a great density of micro-slits (31) that, when they have a uniform distribution, due to their small size and high density, are hardly appreciable to simple seen, offering the blade an appearance similar to a frosted or matt. This is because the micro-slits (31) reduce the intimate contact surface of both surfaces by decreasing the electrostatic attraction forces, and because the micro-slits trap a thin air film (32) separating the protective sheet (2). ) of the delicate surface (4) or the liquid layer (33) that impregnates the delicate surface, notably preventing or reducing adhesion and operating said air film as a sliding shoe, or - reducing the surface of the protective sheet (2) coming into contact with other parts of the protective device or the electronic device, for example, by making the confinement clearance at the edges of the sheet oriented in the direction of sliding (16) less than the clearance in the rest of its surface, as well as raising the guides with respect to the delicate surface, so that the Adhesion force that is created is very reduced because the contact surface is too, because the contact only occurs at the edges (16).

 Other systems or methods that can be used are: coating the sheet with non-stick materials such as, for example, PTFE; coating the sheet with antistatic materials; incorporation into the foil and / or the delicate surface of a band of high conductivity that discharges electrically by contact with the mass; or use sheets and / or delicate surfaces of materials that meet the characteristics specified above or in any combination thereof.

To allow the easy and fast removal of the sheet (2) to be exchanged for another sheet or to proceed with the maintenance of the same, the present invention presents means that do not require the use of tools or the disassembly of part of the electronic device or of its casing. Said means consists in that in the first section of the guiding system (7), which is necessarily accessible to the user, the grooves (7) bordering the delicate surface (4) have an opening (34) on its outer face of very little width that allows the exit or entry of the protective sheet only if the user forces said sheet (2) to reach a curvature that approximates the material to its elastic limit. This "unnatural" way of removing the protective sheet prevents said sheet from coming out through the openings (34) by accident. Although not strictly necessary, it is very convenient that the aforementioned openings are at the beginning of the first section (7), in the place where the sheet stops for closure. However, it is also possible that said sheet can not be removed from the device without disassembling part of it or the electronic device. In the preferred embodiments of this invention, the motive force is of manual origin and direct action on some part of said sheet (2), but in some particular embodiments it may be necessary to introduce mechanical drive systems and / or motorization. One possibility is to arrange an assembly formed by a pair of rotating cylinders (35) with a coating of slightly compressible material (36) such as, for example, rubber or some elastomeric plastic. Said cylinders (35) are located at some point of the sheet almost tangent to each other and separated by a distance somewhat less than the thickness of the sheet to ensure that the pressure on said sheet is adequate. At least one of the cylinders (35) receives the driving force through a drive shaft, a pulley, another cylinder, etc. The cylinders forming the assembly will preferably have the same width as the protective sheet, although they can operate with a smaller width and it is also possible to arrange several rotating assemblies at different points of the protective sheet.

In addition to the protection function of the blade of the device, it can present additional functions, such as:

 • additional blackboard function to write notes,

 • mirror function,

 · Function of second flexible sliding screen, for example of "electronic ink", arranged on a conventional screen, turning the electronic device into a mixed device suitable for reading inside and outside of enclosures,

 • with the appropriate electrical storage and conduction system, the sheets can serve as a photovoltaic panel and provide electrical energy for the operation of the electronic device itself, and

 • means to turn on and off the electronic device when moving the sheet to use or stop using said electrical device.

In the above description, the following abbreviations, symbols and terms have been used: - σ _θ : For the material proper to the point of the sheet considered, maximum tension achievable without leaving the elastic state.

- E _f : For the material proper to the point of the sheet considered, the relationship between the maximum tension attainable in the elastic state and the corresponding unit deformation obtained in the bending test. In the case of materials with linear elastic behavior, this relationship is widely known as "Young's Modulus" in flexion and is constant throughout the elastic period.

- e _e: Maximum unitary deformation in the elastic period, in bending test.

 - R: Radius of curvature of the average surface of the sheet at its point closest to the point considered of said sheet.

- d _sm : Distance from the considered point of the sheet to the average surface of the sheet.

- Edge. It is the geometric limit of a sheet or a surface not necessarily straight.

 - Confine. Reclude within the limits the sheet so that it can not be moved in a different direction to the desired one. The confinement, for the purposes of this invention, is carried out by allowing certain clearances that can be variable, for example, to avoid friction in areas of greater aesthetic value.

 - Ductile fracture. The one that takes place after an appreciable plastic deformation.

 - Throat. Longitudinal concavity or groove of a guide that serves to fit in it the edge of a sheet. The throat is characterized by its width and its depth, which can be fixed or variable. (Section in U, C, etc.)

 - Appropriate degree of flexibility-rigidity. To support the motive force, the external actions and the corresponding reactions without showing deformations that impede the functionality of the system itself, the material of a sheet must be rigid, the more rigid, the greater the acting forces. On the other hand, for the sheet to admit the intrinsic curvatures to this invention it must be flexible, which generates an apparent contradiction that can be solved in several ways:

one . The preferred way to achieve the appropriate degree of stiffness-flexibility is by making the protective sheet with a relatively stiff material but with a sheet thickness small enough so that it can accommodate the desired bends. Thus, the materials usable for the invention, according to this preferred way, are those that are within the range defined by the mathematical expression:

300> (Ε, / (3-σ _θ ))> 1

That, taking into account that E _f = σ _β / ε _β , is equivalent to

1/3> ε _β > 1/900

 By means of this expression applied to any point considered in the structural part of the sheets, those materials that are excessively deformable for the invention are discarded and, therefore, can not transmit efficiently, through their mass, the necessary driving force for the Sliding, and also those whose elastic limit is very low in relation to its rigidity are discarded because they have little capacity to admit the bending without losing essential properties for the operation of this system. And among the materials included in the range defined by the above formula, are preferred for different reasons, which are included in the sub-range determined by the following formula:

50> (E, / (3-σ _β ))> 6

That taking into account that E _f = σ _β / ε _β , is equivalent to

1/18> ε _β > 1/150

 Once the material to be used is established and, therefore, its mechanical properties are fixed, the required thickness can be determined to allow the sheet to admit the curvature designed for the concrete application by means of the following mathematical formula, which must be complied with at all points of the sheet that must be subjected to a certain flexion:

R> (Efdsm) O _e

 And among the forms of sheet that meet the above expression, those that comply are preferable:

R> 4- (Efdsm) O _e

 Well, with this second expression the tensions caused by the bending are smaller and, therefore, more resistant margin is left to absorb forces other than those of bending.

In applications where a sheet thickness (2) is needed superior to that achieved by the previous method, the restrictions of mathematical expressions can be avoided and the appropriate degree of rigidity-flexibility achieved resorting to the realization of sheets of non-uniform section. For example, to achieve a radius of curvature that would exceed the elastic limit of a smooth sheet, a sheet with grooves (37) arranged so that its longitudinal axis coincides with the generatrices of the surface of the sheet curved by the system can be designed. of guidance (1). This gives the sheet the possibility of adapting to the curvatures of the guidance system by forming a surface of polyhedral appearance instead of a perfectly curved surface. The grooves mentioned can have uniform or variable section, such as, for example, rectangular section, triangular section, semicircular section, etc.

 3. Another way of achieving the appropriate degree of rigidity-flexibility without accepting the restrictions of the formulas of mode 1, is to alternate strips of more rigid material (40), with strips of less rigid material (39), the strips being arranged according to the orientation of the generatrices, so that the joint result allows the sheet to adapt to the curvatures of the guidance system, also by means of polyhedral approaches, as in the previous case.

 4. The solutions described in the previous points can also be combined to obtain additional qualities.

See as an illustrative example of mode 1, the following non-limiting table of theoretical material aptitude in which the limit radius has been calculated for some materials in the absence of other forces other than bending forces for sheets of 0.2 mm thickness :

NON-LIMITABLE TABLE OF TEORH FITNESS: A MAT MATTERS FOR LAMIR JAS DE ES PESOR

 CONSTANT AND IV IATERIAL l JNIFORME.

 Ge E e R

 Minimum material (E / 30e)

 kg / cm2 kg / cm2 cm cm

D Rili _Let's ICTJ 1 I ITLOUoC

 Polyethylene APM 200.00 8000.00 0.02 0.40 13.33

Cellulose acetate 1 500.00 40000.00 0.02 0.80 26.67

Cellulose acetate 2 60.00 10000.00 0.02 1.67 55.56

Polycarbonate 1 400.00 23000.00 0.02 0.58 19.17

Polycarbonate 2 300.00 23000.00 0.02 0.77 25.56

Polyamide 6 450.00 14000.00 0.02 0.31 10.37

Polyoxymethylene (Derlin) 700.00 33000.00 0.02 0.47 15.71

Polyesteretherketone (PEEK - 1) 950.00 36500.00 0.02 0.38 12.81

- Sheet (2). It is a three-dimensional geometric body in which its thickness, whether fixed or variable, is much lower than its other two dimensions. A sheet can be made of a single material or be formed of a composition of several materials.

- Straight line. The line that defines the smallest distance between two points of a three-dimensional reference system. In this description, the concept is equivalent to a straight line segment.

 - Curved line. In a three-dimensional reference system, any line that is not straight or has angled sections.

- Micro-slits (31). Roughnesses that have a certain type of protective sheets on its surface consisting of grooves or pores of very small size, preferably less than 25 microns, that are uniformly distributed and in sufficient quantity and density are difficult to perceive individually and give the appearance of a matt or frosted surface and give the sheet anti-stick properties due to wetting and electrostatic forces.

- Guidance system (1). Artifice that allows the sliding of a sheet and at the same time requires that any point of the aforesaid sheet follow unfailingly in its movement a predetermined line that can be traversed in both directions. The layout of the guidance systems may be composed of a simple curve or several tangentially linked curves or alternating curves and straight sections and even have inflection points in which the path of the sheet passes from concave to convex. The guiding system can direct the sheet, at least, confining it only by two of its opposite edges by guides or, at most, confining it in all its surface or also confining it in any intermediate degree between those previously mentioned. The guidance system can include guides, construction planes, rollers, brushes, deflectors and, in general, any means belonging to the current state of the art for this purpose.

- Surface dearróllatele. Those curved surfaces that can be obtained by simple curling of a paper sheet without wrinkles or creases. Also those in which the Gaussian curvature is null in all its points. Cylinder, cone, Móbius tape, etc. - Average surface. Surface that divides a sheet of uniform or variable thickness into two parts of equal thickness. If the average surface is taken as a reference, at any point of that average surface, one face of the sheet is at a distance of + 0.5e and the opposite face at a distance of -0.5e. Being e, the total thickness of the sheet at the point considered.

 - Regulated area. Surface that can be ideally generated by the movement of a straight line called generatrix. In this description, the concept of a straight line is understood as a straight line segment. The preferred examples of embodiment of the invention within the scope of the protection of delicate surfaces of electronic devices are many. However, the specific form that may perhaps have more industrial relevance is that applied to mobile telephony terminals, as these are devices for mass consumption and intense use among the population.

 Among the different types of terminals that currently exist we choose to exemplify the realization, those that incorporate a large touch screen with very few mechanical buttons. In these devices, the screen becomes the means to enter data and to receive it, so it acquires greater relevance and, therefore, it is more interesting to protect it against external aggressions.

 The particular embodiment of the device (0) described in this example is part of a mobile telephone terminal having an approximately rectangular prism shape of substantially less than width and length. The terminal has a touch screen (4) with a large polyester surface on its front face, according to the position of use and a plastic housing (3) such as polycarbonate or the like.

 This protective device incorporated in a mobile telephone terminal (0) comprises, at least:

- A protective sheet (2) preferably made of plastic material such as polyester or the like, with a reverse finish in a matt finish, preferably with a rectangular shape with four edges correlatively designated in the clockwise direction, b _1; b ₂ , b ₃ , b ₄ . Said sheet is arranged in such a way that the edges b ₂ , and b ₄ are oriented in the same direction of movement and the edges bi, and b ₃ in the direction transverse to the movement, A guidance system or means (1) integrated in the own housing (3) of the telephone terminal formed by the following three sections: a first section located in the front part (7) of the terminal, a third section (9) located in the rear or rear part (9) of the terminal and a second section (8) located between the two previous ones and provided with a curve. The first section (7) located on the front of the terminal where the touch screen is also. Said section consists of two guides (7) or slots that are located coincident with the two opposite margins of the touch screen that is to be protected and that border the edges b ₂ and b ₄ of the sheet. Said guides (7) are located in a slightly elevated position (13) with respect to the touch screen to be protected. The distance between both guides suffers a slight point reduction (30) in a place very close to the end of the route. Just after said reduction (30), at the end of the route, said guides have a small opening (34) that serves to insert and remove the protective sheet (2) sliding. The third section (9) at the rear of the terminal that hides and guides the sheet (2) confining all its surface so that it allows a clearance of between 5 and 15 times its thickness at the edges b ₂ and b ₄ and up to 25 times its thickness on the rest of the surface and on the edge b ₃ , avoiding that the surface of the sheet (2) suffer friction except at the edges b ₂ and b ₄ . The second section (8) disposed in one of the edges of the apparatus and in part of its front face that by means of a preferably semicircular design connects the first front section (7) with the third rear section (9). In this second section (8) of the guidance system (1), the sheet (2) runs hidden from view of the user and is where greater frictional force appears because the direction of circulation of the protective sheet (2) is reversed and , therefore, the distribution of the confinement clearances must ensure that all the friction occurs exclusively at the edges b ₂ and b ₄ , to avoid that the visible front of the sheet (2) suffers premature aesthetic deterioration. In this sense, the clearances can be arranged in a relationship similar to those of the section of the rear part (9).

A linear stiffener with rounded ends (25) attached to the edge bi _, which is an edge not linked to the guidance system and which always remains accessible to the user. The length of said stiffener (25) is slightly greater than the distance that results after the point reduction of the spacing of the guides (30). The functions of said stiffener (25) are: a) To avoid that with the normal use of the system, the thin free edge of the sheet is damaged (22, 23, 24) which could reduce its functionality and aesthetic quality,

 b) Prevent the free edge of the sheet from adopting an undesired curvature that could reduce or impede the functionality of the system by derailing (21) of the sheet (2), as shown in Figure 8,

 c) Serve as a distribution element of the manual motive force applied to the sheet by pressing with the fingers on the stiffener itself (25), avoiding a concentration of tensions that can produce nicks and folds (22), dents (23) or tears (24) in the protective sheet, as shown in figures 9 and 10 respectively,

 d) Serve as a rigid support of a cleaning strip (26), and

 e) Allow blocking of the device because the force necessary for said stiffener (25) to overcome the point narrowing (30) in the separation of the guides is predictably greater than any accidental force that could open the device.

- A cleaning strip (26) of felt of micro-fibers of polypropylene or similar, self-adhesive and removable (27), fixed on the back of the sheet under the stiffener (25). Said cleaning strip (26) has the same length and width as the stiffener (25) and a thickness coinciding with the elevation that has been given to the guides (13) of the first section (7) of the guidance system (1) with respect to the touch screen (4). Said cleaning strip (26) has the purpose of sweeping the screen (4) each time the sheet (2) is opened or closed, removing dust and dirt from it.

- A strip of self-cleaning (29) of felt of micro-fibers of polypropylene or similar, self-adhesive and removable, fixed on the back of the housing (3) of the terminal in the place where the guidance system (1) passes from allow the visibility of the sheet (2) to hide it to the user (38). Said strip (29) has the task of sweeping the visible surface of the protective sheet (2) each time it is opened or closed by removing the dust and dirt existing on it.

 In this particular embodiment when the protective sheet (2) is in closed position, it has most of its surface on the front face of the apparatus with respect to its position of use, covering the screen (4). When the sheet (2) is in the open position, it passes to have most of its surface on the opposite or rear face of the same apparatus, leaving the touch screen (4) of said apparatus fully accessible. The retraction of the sheet (2) is possible thanks to the shape and arrangement of the guidance system (1) that leads the sheet to a place where it does not interfere, is not visible and, above all, is not accessible. This is very important for this embodiment, because if the sheet is accessible through the back of the terminal, it could collide accidentally with the user's hand or with any other object causing its derailment or the folding of its surface with the consequent loss of functionality and possible damage to the delicate surface or screen to be protected.

The following is a list of the references used in the figures and in the present description:

0. Protective device for delicate surfaces of electronic devices.

one . Guide system for the sliding blade.

 2. Sliding protective sheet.

3. Housing of the electronic device.

 4. Screen or delicate surface of the electronic device.

 5. Battery of the electronic device.

 6. Internal frame of the electronic device.

 7. First section of the guidance system consisting of a pair of slots or guides. 8. Second section of the guidance system with curvature.

 9. Third section of the guidance system.

10. Realization of the invention in which there are no major formal differences in the entire route of the guidance system. Confinement surfaces formed by necessarily constituent parts of the electronic device.

Confinement surfaces not inherent to the electronic device.

Surfaces highlighted in the guidance system to avoid pressure and friction on the surface of the protective sheet, except at its edges.

Surface of the guiding system that confines the sheet not by the edges oriented in the direction of sliding.

Surface of the protective sheet visible to the user when the device is closed.

Edges of the protective film oriented in the direction of sliding.

Example of tracing the guidance system formed by a simple curve. In this case an ellipse.

Example of tracing of the guidance system formed by several tangentially linked curves.

Example of the layout of the guidance system formed by alternating straight sections and curved sections.

Example of tracing the guidance system with inflection points.

Derailment of the protective sheet by bending the free edge.

Mellas and folds suffered by the free edge of a very thin sheet when applying a driving force on it.

Dents that the free edge of a protective sheet may suffer when a driving force is applied directly on it.

Tears that the free edge of a protective sheet can suffer when a driving force is applied directly on it.

Rigidizer type nervatura applied to the free edge of a protective sheet. Cleaning strip

Removable adhesive arranged on one side of the cleaning strip.

Protective strip of the cleaning strip adhesive.

Strip self-cleaning protective device.

Highlights in the guides to narrow the passage of the stiffener.

Micro-slits.

Air film trapped by the micro-slits.

Liquid layer that impregnates the delicate surface. 34. Opening of the guiding system to insert and remove the protective sheet without tools.

 35. Rotating cylinders.

 36. Compressible coating material for the rotating cylinder.

37. Grooves in a protective sheet.

 38. Place of the protective device where the protective sheet becomes visible to the user if it is not.

 39. Strip of material with less rigidity

 40. Strip of material with greater rigidity

b1 Free edge of the protective sheet accessible to the user who contacts the closing point of the device.

b2. Edge of the protective film oriented in the direction of sliding.

b3. Edge of the protective sheet oriented transversely to the direction of sliding and which does not contact the closing point of the device.

b4. Edge of the protective sheet, different from b2, oriented in the direction of sliding.

Several specific forms of the invention have been extensively tested, of which the most representative of them are described below.

Test n ^Q 1. Model of mobile phone terminal with smooth and continuous laminar protective cover. Model that reproduces a mobile telephone terminal and rectangular prism shape that on one of its sides has a touch type screen, equipped with a device for the protection of the screen by sliding flexible sheet and guidance system formed in the housing itself. apparatus, with the following characteristics:

Width of the terminal. 60, 000 mm

Terminal length 120, 000 mm

Thickness of the terminal 12,900 mm

Useful width of the screen 50, 000 mm

Useful length of the screen 95, 000 mm Surface material of the screen Polyester with hardened surface

Width of the protective sheet 55,000 mm

Length of the protective sheet 130, 000 mm

Thickness of protective sheet 0, 038 mm

Material of the sheet Polyester with matt surface

Minimum radius of curvature of the blade 5.300 mm

Stiffener width 3,500 mm

Stiffener length 49, 500 mm

Thickness of the stiffener. 1,200 mm

Stiffener material. Polypropylene

Guidance system material Polypropylene

Depth of throat of the guidance system 3, 000 mm

Throat width of the guidance system 0,500 mm

Height of the guidance system with respect to the 0.300 mm screen

Material of the cleaning strip Polypropylene felt

Thickness of the cleaning strip 0.300 mm

Material of the self-cleaning strip Felt polypropylene

Thickness of the self-cleaning strip 0,300 mm

In this model, except in the area where the screen is located, the protective sheet circulates inside the housing of the device, so that it is not accessible or visible to the user. Inside the apparatus, the space that exists for the circulation of the sheet is so tight that it does not allow significant flexions in a plane other than that which contains the motion vectors. Therefore, the sheet only needs a stiffener at its visible unlinked end.

 The test consisted in performing 30,000 opening-closing cycles along which the conditions of relative humidity and ambient temperature, humidity of the screen and ambient temperature have varied. Also in each cycle, the person in charge of the test has manipulated the screen with his fingers and every 5 cycles he has put the screen in contact with his face to simulate a real situation.

The test was carried out by alternating open-close test phases with transport phases of the device in a bag that also contained a key ring with a car key, a key ring with five different keys, two pens, a € 2 coin, three € 1 coins and n / € 0.5 coins. All and / or under / as s / gu / entities conditions: Total number of 30,000 trial cycles

Minimum test temperature -15 ^Q C

Maximum test temperature +42 ^Q C

Minimum relative humidity 6%

Maximum relative humidity 100%

Total trial time 100 days

Test regime 300 cycles / day

As a result, the protective film has remained perfectly functional after 30,000 test cycles and the screen of the model has not suffered any noticeable damage after a thorough visual inspection.

 However, in a predictable manner, the following minor type of incidents have been detected:

- When transferring the telephone model of an enclosure to an ambient temperature of - 15 ^Q C to another enclosure with +30 ^Q C and 70% RH, saturation of the air close to the model occurs for a few minutes, with intense condensations appearing on its surface. surface and inside that slightly reduce the proper functioning of the device making it necessary to increase the force applied to produce the sliding of the sheet. However, this adverse effect is not considered relevant because the device always works perfectly after the natural evaporation of the water or its artificial drying, not being so evident that the electronic device can do so.

 The cleaning strips have accumulated dirt and therefore have been washed with a hydrophilic swab and neutral soap every 1,500 cycles.

 - At the end of the test, scratches have been observed on the outer surface of the protective sheet. In the absence of such a sheet, these stripes would have appeared on the touch screen of the mobile phone. Therefore, they are merely proof that the invention has proven effective in this test.

Test n ^Q 2. Mobile telephone terminal model with a laminar protective cover with grooves transverse to the direction of travel located at regular distances. This test is carried out, with characteristics very similar to the n-1 test, to check the functionality of an exceptional variant of the protective sheet, which does not meet the condition R> ((E _r d _sm ) / ( _e )) - Nonetheless , to achieve a radius of curvature equal to that of the test n ^Q 1, the flexibility of the sheet has been increased by carrying out at regular distances a series of grooves arranged perpendicular to the direction of travel. These grooves reduce the stiffness of the sheet in a discontinuous manner to the point that said sheet can slide along the curves of the guidance system transforming into a polyhedral surface instead of a perfectly curved surface as in the n ^Q 1 test.

 In this case, it is also a model that reproduces a mobile telephone terminal and rectangular prism shape that on one of its sides has a touch type screen, equipped with a device for protecting the screen by sliding grooved sheet and system of guiding formed in the own casing of the apparatus.

The model has the following differential characteristics with respect to the n ^Q 1 test:

Thickness of terminal 14, 600 mm

Depth of the grooves of the sheet 0,250 mm

Distance between grooves 1,500 mm

Width of the grooves in the valley 0,080 mm

Width of the grooves on the ridge 0.080 mm

Minimum radius of curvature of the blade 5.300 mm

Stiffener thickness 2, 000 mm

Guidance system material Polypropylene

Thickness of the guiding system 1,000 mm In relation to the n-1 test, it can be said that greater protection of the delicate surface has been obtained, to the detriment of other aspects that may be considered more or less relevant depending on the use to be made of the device. Specifically, the following effects have been observed: The motive force required to slide the protective sheet is noticeably greater and the opening speed is noticeably smaller.

The total thickness of the device and, therefore, of the electronic device increases.

The protective sheet becomes dirtier and cleanser with more difficulty.

Claims

one . Device for the protection of delicate surfaces of electronic devices, characterized in that it comprises: a fixed part, rigid and integral with the electronic device, having a guiding system or guiding means with non-exclusively straight guiding elements, which describe at least one curve, and  a movable sliding part along the guiding system comprising a sheet, confined between said guiding elements and having a degree of rigidity-flexibility that allows the curving thereof without having been previously shaped, so that the moving part it moves between a first position in which the delicate surface is covered by the sheet, facing the lower surface of the sheet, and a second position in which the delicate surface is not hidden behind the sheet, hidden in the part fixed, and said sheet always being comprised in the fixed part of the device. Sliding mobile part of a device for the protection of delicate surfaces of electronic devices according to claim 1, characterized in that it comprises a sheet having its textured surface by a high density of micro-slits, preferably of a width and depth of less than 25 microns, for reduce adhesion due to wetting and adhesion due to electrostatic forces. Sliding mobile part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 or 2, characterized in that the sheet has a multiplicity of grooves arranged in the same direction as the generatrices of the surface resulting from the curved imposed on the sheet by the guidance system. 4. Moving part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 to 3, characterized in that the sheet is formed by a multiplicity of bands that alternate materials of greater rigidity with materials of lower rigidity, said bands being arranged in the same direction as the generatrices of the surface resulting from the bending imposed on the sheet by the guidance system. Sliding moving part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 to 4, characterized in that the sheet is made of a material that fulfills the condition: 300> (E, / 3-σ _β )> 1 Sliding mobile part of a device for the protection of delicate surfaces of electronic devices, according to claim 5, characterized in that the material fulfills the condition: 50> (E, / 3-σ _β )> 6 Sliding mobile part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 to 6, characterized in that the points of the sheet located in the areas to be curved meet the following condition: R> (Efdsm) O _e Sliding mobile part of a device for the protection of delicate surfaces of electronic devices, according to claim 7, characterized in that said points fulfill the condition R> 4- (E, -d _sm ) / σ _β Sliding moving part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 to 8, characterized in that it incorporates a linear stiffening element integral with each of the edges transverse to the direction of sliding of the sheet that does not is prevented from moving in all directions other than the planned slippage. Sliding mobile part of a device for the protection of delicate surfaces of electronic devices, according to claim 9, characterized in that said stiffener has magnetic characteristics. eleven . Moving part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 to 10, characterized in that the sheet has on its lower surface a cleaning strip, such that by bringing the protective film from its fully closed position to its completely open position and vice versa, said cleaning strip sweeps the entire visible surface of the delicate surface, eliminating dirt from it. 12. Moving part of a device for the protection of delicate surfaces of electronic devices, according to claim 1, characterized in that the thickness of the cleaning strip is equivalent to the distance between the guiding elements and the delicate surface. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to claim 1, characterized in that the system or the guiding means comprise at least two guiding elements preferably coincident with two opposite edges of the delicate surface. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1 or 13, characterized in that the guidance system or the guidance means comprise: - A section formed by two guiding elements, preferably coinciding with two opposite edges of the delicate surface, and - One or more sections located in a place that does not coincide with the surface delicate, in which the guidance means are large confinement surfaces not visible to the user of the apparatus. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1, 13 or 14, characterized in that the guiding elements present a point narrowing of the distance between them so that the separation between said elements at the point of constriction is slightly smaller than the length of the stiffener mentioned in claim 9. 16. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to claim 15, characterized in that the point narrowing is preferably located very close to a closing point of the sheet coinciding with the position of the sheet in the that the delicate surface is hidden behind the sheet. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1, 13 or 14, characterized in that it has a magnetic element located at the closing or end point of the sliding coinciding with the position of the sheet in which the delicate surface is hidden behind the sheet. 18. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1, 13, 14, 15, 16 or 17, characterized in that it has a cleaning strip, located in a place of the fixed part, such that by bringing the protective sheet from its fully closed position to its fully open position and vice versa, said cleaning strip sweeps the entire visible surface of the protective sheet eliminating dirt from it. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1, 13, 14, 15, 16, 17 or 18, characterized in that it has at least one roller rotating in the path of the sheet to reduce friction and automate the sliding of the sheet when, said at least one roller, receives a torque from a source of motive power. 20. Fixed part of a device for the protection of delicate surfaces of electronic devices, according to any of claims 1, 13, 14, 15, 16, 17, 18 or 19, characterized in that it forms part of the electronic device. twenty-one . Fixed part of a device for the protection of delicate surfaces of apparatuses, according to any of the claims 1, 13, 14, 15, 16, 17, 18 or 19, characterized in that it is an accessory element and independent of the electronic device, to which it is fixed, without thereby affecting the normal functionality of said electronic device. 22. Moving part for sliding along a system or guiding means, with at least one curve, of a device for the protection of delicate surfaces of electronic devices, characterized in that it comprises a sheet having a degree of rigidity-flexibility that it allows the curving thereof adapting to at least said curve of the guidance system. 23. Fixed part for the protection of delicate surfaces of electronic devices, characterized in that it has a guiding system or guiding means with guiding elements of not only straight tracing, which describe at least one curve.