SENSITIVITY-MODIFYING DEVICE FOR TOUCH-SENSITIVE PANELS

Abstract: A device for modifying the touch sensitivity of faces or panels that are capable of registering touch by pressure. The device, for example, made in the form of a flexible sheet having a substantially smooth first surface and an opposite second surface provided with pointwise projecting irregularities, can be placed with the second surface against touch-sensitive computer screens and the like and transmit to the screen pressure on the first surface via the points on the second surface with a greater contact pressure at the contact points.

Description: SENSITIVITY-MODIFYING DEVICE FOR TOUCH-SENSITIVE PANELS The invention relates to the field of touch-sensitive panels such as, for example, touch- sensitive faces of computer screens. More specifically, it relates to a device for placing on touch-sensitive faces in order to control the sensitivity properties of such faces. Modern portable computers, mobile telephones and other apparatus are often provided with display screens or control faces that are sensitive to touch by pressure, so that, for example, by applying pressure on particular areas or sections of a screen or face it is possible to make choices according to displayed options. The input of data into apparatuses, for example, can also be done in the same way. In order to choose surely and effectively between displayed alternatives or to enter data where the density of the sections on the screen is high, a pen-like device is used in many commercially available appliances. The pen device is so designed that on normal use it applies a specific pressure per unit area that exceeds the pressure per unit area of the normal pressure contact of a finger or palm of a hand. Many touch-sensitive faces utilise this fact by having through their design a sensitivity that is such that unintended contact of, for example, fingers or the palm of a hand is not registered whereas the pressure from the pen device is. In some cases and situations it may be difficult or undesirable to operate such touch- sensitive faces with a pen device. For example, mobile telephones or measuring instruments provided with touch-sensitive faces, intended for operation using a pen device, that are to be used in adverse environmental conditions where the operator, for example, is wearing protective gear such as gloves or the like. Certainly, there are touch-sensitive faces such as, for example, some touch-sensitive computer screens, which have a sensitivity adapted to a pressure that can normally be obtained using one or more fingers, but these are often expensive and designed for particular products or uses. Moreover, such commercially available touch-sensitive faces often have the same sensitivity across the whole face. There is therefore a need to provide a touch-sensitive face for, e.g., a computer screen, which can preferably be put on the market at a price that is in the range of normal consumer products, where the touch sensitivity is such that it will register a contact pressure that can be produced by a body part or a similar control means. There is also a need to be able to adapt touch faces on apparatus such as, for example, a mobile telephone or a measuring instrument designed for operation with the aid of a pen device, so that they can wholly or partly be operated without the use of the pen device. In modern communication technology it has been found extremely useful for individuals with reduced mobility or other disabilities to use touch-sensitive screens to facilitate their communication with other individuals or to operate other apparatus. One example of such a use is a touch-sensitive computer screen for individuals suffering from a condition that causes impaired mobility, which is used to control synthetic speech and for the control of a wheelchair or other devices. However, a problem that is constantly encountered is that many potential users have different patterns of movement or varying degrees of the ability to apply pressure to a touch-sensitive screen of this kind. There is therefore a need for touch-sensitive faces or an adaptation of such faces for, e.g., a touch-sensitive computer screen, in order to tailor the touch sensitivity to the individual, or to make a greater range of products having such faces available for wider applications and for more individuals. JP 7169367 A relates to a touch- sensitive panel with high sensitivity, which panel includes a transparent basic material having a surface that has intentionally been made irregular with a roughness disclosed as between 0.06 and 3.0 μm. However, the basic material is joined to, and thus integrated with, one of the electrode layers that form a part of the registration mechanism of the touch-sensitive panel. DE 29811904U describes a protective device for a touch-sensitive face of the capacitive type, where the protective means is made in the form of a thin, transparent plastic film placed immediately adjacent to the touch sensitive face. The film is disclosed as having a thickness of between 1 and 15 μm, in order to be fastened to a frame adapted to the touch-sensitive face. EP 0111879A3 describes a multi-layer photoelectric touch-sensitive face for placement on a light-emitting screen, where one of the layers includes a surface having a plurality of irregularities positioned in a controlled manner, and integral in the structure of the touch-sensitive face, which act to maintain a certain distance between different layers that form the registration mechanism. JP 8235963 A relates to a multi-layer touch-sensitive face where one of the layers of the face structure, which also constitutes a part of the face registration mechanism, includes projecting irregularities so positioned that the distance between the registration mechanism is reduced in order to obtain better accuracy of registration when a light touch is applied to the face It is thus an object of the present invention to provide a device which allows adaptations of touch-sensitive faces, preferably at a cost that is within the range for ordinary consumer products, whereby the touch sensitivity can be adapted in such manner that the faces will register contact pressure corresponding to pressure that can be produced by using a body part or a similar control means It is another object of the present invention to provide a device which makes possible a touch-sensitive face capable of adaptation to the individual, preferably at a low cost, and which permits variation of touch-sensitivity across the touch-sensitive screen It is a further object of the present invention to provide a device that can be used to modify the touch sensitivity of faces that are sensitive to pressure contact These objects are attained by means of the present invention, which provides a device having the features disclosed in the attached patent claim 1 The invention also provides methods for the manufacture of a device as disclosed in the attached patent claims 9 and 10 Other embodiments of the invention are disclosed in the attached dependent patent claims 2-8 The invention will be explained in more detail in the following with reference to the attached drawings where Fig 1 shows a touch-sensitive computer screen of the pen-type combined with a touch- sensitive modifying device according to the invention made in the form of a film, Fig 2 is a schematic sectional view of the combination in Figure 1, Fig 3 shows an enlarged area of a film embodiment of the invention as shown in Fig 1 Fig 4 shows a film embodiment of the invention as used in the combination in Fig 1, Fig 5 is a schematic sectional view of a touch-sensitive computer screen of the pen type combined with a second embodiment of a touch sensitivity modifying device according to the invention, Fig 6 is a schematic sectional view of a touch-sensitive computer screen of the pen type combined with another embodiment of a touch sensitivity modifying device according to the invention, Fig 7 is a schematic sectional view of a touch-sensitive computer screen of the pen type combined with a further embodiment of a touch sensitivity modifying device according to the invention In the following the invention will be explained with the aid of some examples and embodiments Reference is first made to Fig. 1 where the invention is shown in the form of a flexible sheet or film that provides a pressure-boosting effect when placed on top of a touch- sensitive face that is responsive to pressure, the sheet or film being placed on the computer screen of an ordinary commercial type designed for operation using a pen When the force of a finger is applied to the sheet or film on an area on one of the sides, the force on the sheet or film will be concentrated in one or more smaller areas on the other side facing the touch-sensitive screen The pressure-boosting effect is achieved in that the flexible sheet or film has a first surface on the operating side that is substantially even or regular, whilst a second surface on the side facing the touch-sensitive face has an uneven or irregular second surface Thus, it is ensured that pressure applied to the operating side is transmitted to an underlying touch-sensitive face via a limited number of contact points provided by the structure of the second surface with a resulting higher contact pressure in each of the contact points In one embodiment of the invention the device can be so formed that the pressure necessary for registration is the same across the whole face, whilst in a second embodiment it is formed so that the pressure required by some areas is different from that required by others Areas of the face may also retain properties almost identical to those the operating unit had at the outset before the device according to the invention was placed on the operating unit. The device according to the invention has been implemented in an aid for persons suffering from aphasia, a condition involving impaired speech or the inability to speak. The aid functions so as to allow the person to communicate by pressing letters or symbols for sentences or clauses. When individual choices have been made, or when the person has "composed a message", the aid emits synthetic or digitised speech with the aid of a computer. For large parts of this group of potential users it is best to use a finger or another part of the hand, or another blunt object to touch the touch-sensitive screen. It is also desirable that it should not be possible to touch the menu unintentionally, which means that a part of the screen should be excluded from the user's control equipment. Another means, e.g., pen, mouse and/or keyboard can be used instead to operate the menu selection of this kind Another application example is the device in the form of a sheet or film that is adapted to a mobile telephone provided with a regular pen-based touch-sensitive display, where the device may, if desired, be hinged to the mobile telephone housing. When the device is put in position immediately adjacent to the display, a telephone number, for example, can be keyed by applying light or medium finger pressure without the use of the pen means. The device may possibly also be provided with structures or visible information on the operating side to enable the operator to feel or see the relevant areas that are to be used to operate the apparatus. A further application example is in a situation where there are special environmental conditions such as intense cold, heat or radioactivity. The device in the form of a sheet or film can then be adapted to a standard apparatus such as a measuring instrument or a mobile telephone provided with a touch- sensitive panel or display, so that the device adjusts the sensitivity, thereby allowing the apparatus to be operated despite the operator having to wear gloves or other restrictive protective gear. The invention is primarily intended for use with computers of a type designed to be operated by a pen. Computer screens for pen operation require pressure on a point or very great pressure on an area in order to be operated. Therefore, computers of this type are not easy to operate by pressing with a finger or another soft object without it being necessary to press very hard. By mounting the invention in the form of a see-through film or sheet over the screen, the machine can be operated by pressing with, for example, a finger, or with the side of the hand, a toe or another body part It is also possible to touch the screen with an object and have the touch registered An operating unit having a touch-sensitive screen, shown in Fig 1 , more specifically an operating unit of the type Fujitsu Point 1600 used in conjunction with the invention, has a separate menu area at the bottom of the screen This unit, which is commercially available, is a so-called POS (Point of Sale) unit The typical use of the unit is for travelling salesmen who use it to fill in by hand electronic documents such as, e.g , order forms, where the screen should preferably not register a hand placed on the screen whilst the user with the aid of a pen means fills in, for example, an electronic order form For other applications, it will be desirable to modify the touch sensitivity across a large part of the screen, whilst it is desirable that the menu area should retain its operating properties so as to render it impossible for the user on unintentionally touching of the menu area to make choices which change the properties of the operating unit per se In this case, the device has been so designed that the original operating properties have been maintained in the menu area with the result that this area must be operated using a pen or another implement having a narrow point if the contact is to be registered in accordance with the original structural purpose of the screen The device according to the invention is intended to be capable of being factory- mounted in an operating unit having a touch-sensitive control face by opening the unit and installing the device in the form of, for example, a flexible sheet or film adapted to the unit Alternatively, the device of the invention can be retrofitted by, for example, gluing or fastening the device in some other way to the unit or to parts of the touch-sensitive face of the unit The intention is that the device made in the form of, for example, a sheet or film, is cut to fit, for example, the screen size or the touch-sensitive face of the computers or units in question Optionally, the film or layer of film may be larger than the screen to facilitate cleaning or to protect the unit from, e g , the elements Once the device has been mounted, the user can operate, e g , a personal computer (PC) using a pen-based touch screen by pressing the screen with a finger instead of having to use a pen In a number of applications of the invention it is important that the visibility of the screen when used indoors or outdoors does not suffer a substantial reduction This applies to both surface reflections and implementation of the pressure-boosting properties The face of the inventive device that is to receive touches will often be exposed to the elements and should be easy to clean as regards finger grease, spittle and food debris The surface should also be wear-resistant so that it withstands frequent and prolonged use These requirements can be met by ensuring that the device itself or the upper layer of the device covers the whole of the front or face of the machine or unit, and that desired areas have pressure-boosting effect A number of embodiments of the inventive device have been developed, as have a number of methods for the manufacture thereof In the following the different production methods and the products resulting therefrom will be described and discussed In the first method, method A, a composite film, shown schematically in Figure 2, was made, which composite film comprised two films, film 1 and film 2 respectively, wherein -film/sheet 1 anti-reflection coated film or sheet to prevent the user from being distracted by the sunlight, easy-to-clean flat film (food debris, finger grease etc ), wear- resistant stands both pen and finger (depending upon film 2, some areas can only be operated by a pen, menu line at the bottom of the screen in this embodiment is pen- based, the rigidity of the film means that the pressure from a finger is distributed to the surrounding structure in film 2, the structure in film 2 can therefore be more spread, even with a thin film 2, and the film also prevents disturbing reflexes from film 2), and - film/sheet 2 pressure-boosting film, the film concentrates the pressure in small pressure points thereby allowing a greater pressure to be obtained in the small pressure points per unit of area than in the original pressure, the film is stamped or placed in the sections where it is desired that the screen is to be operated by a finger or other soft object In a first embossing method film 2a was made by selecting film 2 as a thinner plastic film than film 1, and perforated the film using pointwise stamping The burrs around the holes functioned as pressure points In a similar stamping method, film 2b was made by choosing film 2 as a thinner plastic film than film 1, and stamping the film using needles but without the needles perforating the plastic The plastic was stretched at the "needle points" so that "small knobs" were produced that functioned as pressure points in the finished device Figure 3 shows an enlarged section of the film including several pressure points The stamping of the films was done at room temperature, hot liquid bath and heat chamber Heat was used to avoid the visual effect of white in the film where the film material was stretched to permanent deformation In another similar stamping method film 2c was made by placing plastic film 2 on top of a perforated sheet Both the film and the sheet were enveloped by a "bag" to form one unit The air in the bag was then withdrawn so that a vacuum was created in the holes under the film The unit was then placed in a heat chamber so that the film softened and was drawn down a little into the holes The film then had small rounded knobs at the sites of the holes in the sheet By varying temperature, time and pressure small knobs are produced that wholly or partly fill the holes In a further method, film 2d was made by punching the plastic film 2 out in a grid so that the remaining areas functioned as pressure-boosting "strips" In another similar stamping method, film 2e was made by stamping grooves in plastic film 2 by using a suitable roller without the groove configuration on the roller perforating the film On stamping one side of the film with a roller, the plastic material was stretched out in the groove track, thereby producing projections on the other side of the film, which functioned as pressure points Fig 4 shows a device according to the invention made according to method A that is shown schematically in Fig 2, where a film, which in the above is referred to by 2a, forms the surface of the device having projecting points (small knobs) which are to rest against a touch-sensitive face when the device is in use A device according to the invention manufactured by method A can be assembled in a number of different ways such as a) the films are placed immediately on top of one another without any layer between the films, b) to obtain better view through the film, the layer between films 1 and 2 (2b, 2c or 2e) is "wetted" with liquid, e g , silicone fluid, and films 1 and 2 are glued at the edges to prevent the entry of air, c) the films are glued together using a two-component silicone in a thin layer between the films, or laminated in that film 2 is a stamped laminated film, or laminated using heat, or laminated in that film 2 is a film provided with glue on one side In a second method, method B, a composite film, shown schematically in Fig. 5, was made, and this film comprises three films, film 1, film 2 and film 3 respectively, wherein: a) to improve the visual effect films 2a-2e were placed in liquid between film 1 and film 3; films 1 and 3 were welded or glued at their outer edges; b) film 2 was laminated between films 1 and 3 ; c) fine threads (fishing line) were laminated between films 1 and 3; and d) film strips, "flat threads", were laminated between films 1 and 3. In a third method, method C, a film as shown schematically in Figure 6 was produced, and this film comprises only one film, wherein; a) the second surface of the film was structured using a hot stylus so that projections emerged on the plastic either in the form of points or strips without the first surface being touched or affected; and b) the second surface of the film was structured using a stylus at room temperature so that projections emerged on the plastic either in the form of points or strips without the first surface being touched or affected. In a fourth method, method D, a film, shown schematically in Figure 6, was made, and this film includes only one film, alternatively two films, and small plastic balls which are preferably transparent, wherein; - transparent plastic balls of identical diameter are placed on the film which is then wetted with a solvent so that the outermost layer of the balls and the film fuse together; alternatively the film can also be attached to an additional film on the underside with a wetted layer therebetween to improve the optical properties. In a fifth method, method E, a device according to the invention was made wherein: a) balls of identical diameter are "baked" into an oil layer between two films; or b) balls of identical diameter are "baked" into a silicone layer between two films. It has been found that the manufacture of the device according to the invention should preferably be done according to method A as this is the cheapest and easiest method of production and is well suited for use in small production series. However, it is clear that the device according to the invention can both be made by a number of different methods and be used in a number of different ways as will be obvious to the skilled person after reading the description of the invention. The examples of the methods of production, the embodiments and the applications described in the above are merely intended to illustrate and explain the invention and should thus not be understood as defining the limits of the invention.

Claims: P a t e n t c l a i m s 1 A device for placing on panels or faces that are touch-sensitive upon the registration of pressure, such as pen-based touch-sensitive computer screens, in order to modify or control the touch sensitivity, characterised by a substantially flat, flexible element having on one side a first surface and on the opposite side a second surface, wherein the first surface is essentially a smooth face suitable for touch using a part of the body such as a finger, hand, toe or the like, or another blunt object, wherein the second surface is, in most of the element, in generally constant or sporadic communication with the first surface for transmission of pressure applied on the first surface to the second surface; and wherein the second surface exhibits a controlled number of projecting irregularities with or without any touch pressure being applied on the first surface of the element 2 A device as disclosed in claim 1, characterised in that the element is made of a transparent or see-through material 3 A device as disclosed in any one of the preceding claims, characterised in that the projecting irregularities on the second surface of the element are distributed in a predetermined pattern 4 A device as disclosed in any one of the preceding claims, characterised in that the element is formed of a combination of two or more layers of flexible plastic material or film material 5 A device as disclosed in claim 4, characterised in that a least one sheet layer or film layer is provided with projecting irregularities 6 A device as disclosed in claim 4, characterised in that the space between the layers comprises a fluid and solid particles of a regular shape 7 A device according to claim 6, characterised in that the particle shape is spherical ellipsoid or cylindrical 8 A device as disclosed in claim 6 or 7, characterised in that the fluid and the particles are transparent 9 A method for making, by partially softening a material by heating to a certain temperature, a face having projecting irregularities into a device for placing on faces that are touch-sensitive upon the registration of pressure such as pen-based computer screens for modifying or determining the touch sensitivity, characterised by placing a sheet or film of flexible material that softens when heated on top of a rigid sheet of material that does not soften when heated, the rigid sheet being perforated with a specific pattern of holes, enveloping the sheets to form one unit so that a closed spaced can be formed under the rigid sheet, providing a vacuum in the closed space under the rigid sheet, heating the unit until the flexible material softens and is partly drawn into the openings in the perforated rigid sheet by the vacuum, and neutralising the vacuum and cooling the unit 10 A method for making, by partially softening a material by heating to a certain temperature, a transparent or see-through face having projecting irregularities into a device for placing on faces that are touch-sensitive upon the registration of pressure such as pen-based computer screens for modifying or determining the touch sensitivity, characterised by heating a sheet or film of flexible transparent material to softening point, heating a suitable stamping tool and stamping the softened sheet of film with the stamping tool so that projecting irregularities are formed in at least one surface of the sheet or film in a specific pattern without substantial whitening being produced in the stamped material

Inventors: JOHNSEN OEYSTEIN, JOHNSEN, OEYSTEIN
Applicants: JOHNSEN OEYSTEIN, JOHNSEN, OEYSTEIN
Application year: 2000
Main classification: G06F3
IPC codes: G06F3