WO2025007174A2 - Touch screen input system and method - Google Patents

Abstract

The invention relates to a touch screen input system that has at least one visually perceptible button at least at one position, said touch screen input system comprising: an active inductive input device that is designed to generate an electromagnetic alternating field; a touch-sensitive layer that is designed to detect actuations of the touch-screen input system by the input device and to capture first items of position information of the input device; a conductor loop layer that is designed to detect the electromagnetic alternating field and to determine second items of position information of the input device by comparing induction signal strengths; and a computing device that is designed to verify whether the first items of position information, the second items of position information, and the button position match, and, if they do match, to trigger the button when an actuation is detected by the touch-sensitive layer. The invention also relates to an input method and to a computer program product.

Description

TOUCH SCREEN INPUT SYSTEM AND INPUT METHODS

The invention relates to a touch screen input system and an input method therefor.

Touch screen input systems, also called touch screens, are screens that respond to touch by fingers or input devices, for example, and are used, for example, in the operation of machines and devices. In various applications, safety is desired or even required in order to avert danger to people, i.e. to prevent injury. In order to ensure safe operation of machines and devices, it must be prevented that unintentional touches trigger unwanted actions or processes.

The forerunners of modern touch screens were systems based on pens that, when placed on a cathode ray tube, amplified and supplemented the existing signal. This made it possible to display drawings on screens. Further developments made it possible to separate teletype pens from their mechanical connections so that what a user drew on a screen could be stored by transferring it to a computer.

Later, touch screens were developed that worked independently of the light from the screen, because they used a matrix of collimated, i.e. parallel, light beams that shone orthogonally across the surface of the touch screen. If a beam was interrupted by a pen, photodetectors that no longer received a signal could determine the point of interruption and thus the position of the pen.

The next developments were finger-controlled touch screens, which could detect the touch of the touch screen with one finger, and later also so-called multi-touch screens, which could detect several fingers at the same time.

With the introduction of multi-touch systems, input pens such as touch pens became less and less important, but the advantages of pen-like operation later led to pens being used more and more for handwriting, drawing and also for operating buttons, for example. Many modern high-end devices such as smartphones, tablets and laptops can also capture inputs made with pens and also implement various additional functions.

In addition, touch screens are used to operate machines, to display information, for example in department stores or train stations, to carry out transactions, for example at ATMs or ticket machines, or for combined purposes, such as in vehicles for communication, information and control.

In recent years, hybrid touch systems have been increasingly introduced that allow inputs to be made by simply touching a user's finger, for example to operate buttons or for inputs via keyboards shown graphically on a subordinate display, as well as precise, fine inputs using a stylus. These hybrid touch systems have resistive or capacitive touch sensors for detecting touches using fingers, as well as conductor loop layers for detecting the position of inductive styluses, whereby these styluses can be detected both via the conductor loop layer and via the touch sensor if they are suitably designed. Such hybrid touch systems are used, for example, in high-priced tablet computers.

When using such hybrid touch systems, the main problem that has arisen so far, as long as both sensors are activated at the same time and the user does not have to manually preset one of the two input methods, is unwanted contact with the touch surface with the hand during the actual input using the stylus.

US 11,221,688 describes an input device with a pen display position detector that detects a pen position indicated by an electronic pen held by a user on an input surface, a touch position detector that detects a touch position touched by the user on the input surface.

EP 2 631 749 describes a hybrid touch screen device that is applied to an electrical device and detects an input event by a direct touch. The pen touch panel detects a touch pen input and an input event by an input in a given detection position before a touch. An input event from the touch pen and an input event from the touch panel are detected independently of each other.

EP 2 674 849 describes a method for controlling a touch input of a terminal. The method includes determining a touch position when a touch input is detected and setting a portion of a touch pad including the determined touch position as an effective touch area of the touch pad. The method may further determine whether the touch input is a pen touch input.

In the field of industrial machine controls, conventional touch screens with capacitive or resistive touch sensors, which do not yet have the hybrid features described above, have been used for many years and are used there for flexible and intuitive operating concepts in conjunction with graphic diagrams and process representations. Depending on the type of machine or process, certain operating actions or settings can sometimes pose significant potential risks, particularly to people's lives and health, but also to property. Suitable measures must therefore be taken to ensure that such operating actions are only carried out consciously, without error and only by trained and authorized persons. In addition, it must be ensured that individual technical defects or malfunctions in the control system and the associated operating devices cannot lead to the unintentional triggering of such functions and thus endanger people.

While certain non-time-critical inputs, such as parameter changes, can be secured against unintentional and unauthorized changes by means of security queries and additional confirmations, this is not practical for functions with a direct temporal connection between actuation and execution. This applies, for example, to the movement of machine axes or robots only as long as and to the extent that an authorized user operates an assigned control element (so-called hold-to-run function). This particularly applies to special operating states of machines in which other protective measures such as safety doors or fences are temporarily opened and thus rendered inoperable, e.g. in During adjustment, setup, repair or maintenance work on machines (e.g. injection molding machines or machine tools).

To date, only specially safe switching elements and control components, particularly those with two circuits, have been used in industrial environments for the immediate triggering of potentially dangerous functions and movements, whereby the associated machine function is only triggered when both circuits (e.g. two contacts) signal an actuation at the same time.

The authority of operators is checked, for example, by using password queries or key switches.

The disadvantage of the state-of-the-art solutions is the considerable additional space required for such secure operating elements, the associated costs and the lack of flexibility in terms of number, positioning or function assignment. In addition, the authorization of an operator can only be checked via additional queries or by key switches or the like, but not directly during an operating action, so that after a positive check of an operator's access authorization and the activation of certain functionalities, it may well happen that another, unauthorized person subsequently carries out operating actions while, for example, the previously authorized person leaves the operating terminal in the meantime and inspects parts of the system or machine or carries out work on it.

The object of the present invention is to overcome the disadvantages of the prior art and to improve the safety of touch screens, and to create a flexible touch input system for the execution of dangerous or safety-critical machine functions with improved safety against external interference, technical defects and unauthorized and unwanted operating actions.

A touch screen input system, an input method for a touch screen input system and a computer program product are provided. The object of the invention is achieved by the subject matter of the independent claims. Advantageous further developments can be found in the dependent claims.

This object is achieved in particular by using an input system with at least two independently effective sensor systems, i.e. with hybrid touch features, for essentially simultaneous and independent detection of the position of a touch pen on an input surface, checking the respectively detected position for agreement with the surface of an operating element defined on the input surface by a computing unit and triggering a machine function assigned to the operating element in terms of control technology by the computing unit.

By using two technologically diverse sensor systems for detecting the actuation and the input position, it is ensured that incorrect actuation or position detection, for example due to a single technical defect, dirt, moisture or electromagnetic interference or even simply due to unintentional contact with the hand, does not occur through both sensor systems and not in the same way, and by checking the plausibility of the results of both sensors, an unintentional triggering of the function is reliably avoided.

In addition, the activation of potentially critical machine functions requires the use of a touch pen, whereas non-critical settings or status queries can be made on the same operating terminal, for example, without a touch pen and using only the conventional touch sensor, so that the touch pen and its assignment to an authorized operator already have a certain function as a key in this simple form.

Another advantage of the mandatory use of the touch pen for safety-critical machine commands is that it is clear to the user which of several buttons displayed he selects with the tip of the pen and thus activates. Simply touching such a button with a finger or the palm of the hand can either be ignored or can be used in certain cases to inform the user of the mandatory use of a touch pen. In this case, the actuation of buttons would be registered and non-critical functions would be hidden behind the The corresponding buttons are also executed, but safety-critical functions are not executed, and the operator is informed that such a critical function is only permitted by a touch pen, possibly with special authorization.

Furthermore, when using an unauthorized or authorizing touch pen, a corresponding notice is conceivable, informing the operator that the operator cannot perform the intended function with the input device used.

An advantageous further development provides that the inductive touch pen modulates a code that identifies the respective pen and can be detected by the conductor loop layer onto the magnetic field it generates or influences, which makes the touch pen technically distinguishable from other, otherwise identical pens and thus significantly expands the functionality as a key for checking the authorization of an operator or, in an industrial environment, enables a more selective allocation of authorizations to individual users.

For some applications, a particular level of security during input is desired or required. The present invention can reduce additional switching elements and/or realize additional application possibilities and functions by means of secure touch input.

In the following, the embodiments of the invention are set out, whereby it is pointed out that the embodiments can generally relate both to the system and to the alternative implementation forms (method, computer program product, etc.).

In a first aspect, according to a first embodiment, a touch screen input system is provided which has at least one visually perceptible button at at least one position. The touch screen input system comprises an active, inductive input device which is designed to generate an alternating electromagnetic field, a touch-sensitive layer which is designed to detect operations of the touch screen input system by the input device and first position information of the input device, a conductor loop layer which is designed to to detect an alternating electromagnetic field and to determine second position information of the input device by comparing induction signal strengths, and a computing device which is configured to check whether the first position information, the second position information and the button position match and, if so, to trigger the button when actuated by the touch-sensitive layer.

A match within the meaning of this document does not have to be an exact match, but can be subject to tolerance, i.e., for example, when a button is pressed, a predeterminable edge area of a button also leads to the button being pressed. A match in positions is therefore also determined if there are deviations in the coordinates or areas being compared to a technical extent. This particularly concerns deviations that are in the order of magnitude of the detection accuracy, for example a few millimeters or that are smaller than the gaps between two adjacent buttons.

The advantage here is that the button is only triggered if the position of the input device has been determined by two systems in agreement. This means that the button cannot be triggered accidentally, for example by the palm of the hand being placed on the screen or by a part of the body hitting the touch screen input device. In addition, this enables triple confirmation, since the two determined positions must match the known position of the button.

In a further embodiment, each of the at least one button has a fixed position on the touch screen input system.

The fixed positioning of buttons makes it possible to place safety-relevant functions in places that are rarely touched accidentally, e.g. in the upper touch screen area.

In a further embodiment, the input device is further configured to modulate additional input device information onto the alternating electromagnetic field. The computing device is then further configured to determine the additional input device information from the detected alternating electromagnetic field and to trigger the actuation of the button only if the additional input device information meets criteria stored for the button.

This has the advantage that, for example, input devices can be assigned an authorization, meaning that certain functions can only be performed by authorized input devices.

In a further embodiment, the input device comprises a pressure detection device which is designed to detect the pressure with which the input device is pressed onto the touch screen input system, and the additional input device information comprises the detected pressure. The input device can also alternatively or additionally comprise a fingerprint reader and the additional input device information can comprise a read fingerprint. Alternatively or additionally, the input device can have stored identification information and the additional input device information can comprise the identification information.

In a further embodiment, the touch-sensitive layer is further configured to detect direct actuations of the touch screen input system by an operator and third position information of the direct actuation, and the computing device is further configured to output a notice indicating the need for an input device for a first group of buttons that can only be triggered by an input device; and for a second group of buttons that can also be triggered without an input device, to check whether the third position information and the button position match, and if so, to trigger the button in the event of a direct actuation detected by the touch-sensitive layer.

This makes it possible to advantageously implement a mixed input mode (so-called mixed mode), in which, for example, buttons in a first group, which can then trigger safety-critical operations, can only be activated using an input device. This can create additional safety, as the risk of unintentional activation by the operator can be reduced. The Buttons in a second group, which can then trigger non-critical actions, such as menu control buttons or buttons that affect the display, can be triggered without an input device. The term "direct actuation" here means an actuation by the operator without an input device and can refer to touches with one or more fingers, the palm of the hand, a forearm, an elbow, or other parts of the body.

In a further embodiment, one of the criteria stored for the button comprises identification information of a predetermined input device from a set of several similar input devices, wherein the identification information of the predetermined input device is registered in the stored criteria by a user using the specific input device.

Because an input device can only be used once it has been activated with an additional registration, a lost input device can be easily replaced and mixing up input devices cannot have any negative consequences. In addition, a lost or stolen input device does not enable an unauthorized third party to operate the system.

These are advantageous further developments, which will be explained in the further course of the description.

According to a further aspect of the invention, an input method for a touch screen input system is described, wherein the method comprises detecting an actuation of the touch screen input system with the input device by the touch-sensitive layer, detecting the first position information of the input device by the touch-sensitive layer, detecting the alternating electromagnetic field by the conductor loop layer, and determining the second position information of the input device by the conductor loop layer by comparing induction signal strengths, checking by the computing device whether the first position information, the second position information and the button position match, and if they match, triggering the button when actuation of the touch screen input system is detected. Another advantage here is that the button is only triggered if the position of the input device has been determined by two systems in agreement. This means that the button cannot be triggered accidentally, for example by the palm of the hand being placed on the screen or by a part of the body hitting the touch screen input device. In addition, this enables triple confirmation, since the two determined positions must match the known position of the button.

In a further embodiment, the input method further comprises modulating, by the input device, additional input device information onto the alternating electromagnetic field, and determining, by the computing device, the additional input device information from the detected alternating electromagnetic field, wherein the button is only triggered if the additional input device information meets criteria stored for the button.

This also has the advantage that, for example, input devices can be assigned an authorization, meaning that certain functions can only be carried out by authorized input devices.

In a further embodiment, the additional input device information includes the pressure with which the input device is pressed onto the touch screen input system, a fingerprint and/or identification information of the input device.

In a further embodiment, the method further comprises detecting a direct actuation of the touch screen input system by an operator through the touch-sensitive layer, detecting third position information of the direct actuation through the touch-sensitive layer. For a first group of buttons that can only be triggered by an input device, a note is then issued indicating the need for an input device for actuation, and for a second group of buttons that can also be triggered without an input device, the method comprises checking by the computing device whether the third position information button position match, and if there is a match, the button is triggered when a direct actuation of the touch screen input system is detected.

This advantageously makes it possible to implement a mixed input mode (so-called mixed mode), in which, for example, buttons in a first group, which can then trigger safety-critical operations, for example, can only be activated using an input device. This can create additional safety, as the risk of unintentional activation by the operator can be reduced. The buttons in a second group, which can then trigger non-critical actions, such as menu control buttons or buttons that influence the display, can, however, be activated without an input device. The term "direct activation" here means activation by the operator without an input device, and can refer to touches with one or more fingers, the ball of a hand, a forearm, an elbow, or other parts of the body.

These advantageous further developments will be explained in the further course of the description.

According to a further aspect of the invention, a computer program product is described which can be loaded directly into a memory of a programmable control device of a touch screen input system, with program code means for carrying out all steps of a previously described input method when the program product is executed on the control device.

The embodiments show possible variants, whereby the invention is not limited to the specifically illustrated variants, but rather combinations of the individual variants with each other are also possible. In particular, the features of the system can also be implemented in a method and vice versa.

For a better understanding of the invention, it is explained in more detail using the following figures. They each show in a highly simplified, schematic representation:

Fig. 1 shows a touch screen input system according to exemplary embodiments, Fig. 2 an exemplary input device of the touch screen input system, and

Fig. 3 is a schematic flow diagram according to exemplary embodiments.

To begin with, it should be noted that in the different embodiments described, identical parts are provided with identical reference symbols or identical component designations, whereby the disclosures contained in the entire description can be transferred analogously to identical parts with identical reference symbols or identical component designations. The position information chosen in the description, such as top, bottom, side, etc., also refers to the figure directly described and shown, and these position information must be transferred analogously to the new position if the position changes.

Compared to known systems, higher security can be achieved, for example, via a two-channel architecture.

Control architectures were divided into categories by the DIN EN 954-1 standard, which describes the classification of the safety-related parts of a control system with regard to their resistance to faults and their subsequent behaviour in the event of a fault. Five control categories were defined (B, 1, 2, 3, 4), with categories 3 and 4 relating to two-channel architectures.

Since 2009, the categories have been replaced by performance levels, which are defined in DIN EN ISO 13849-1. The performance levels, PL, are marked with the letters a to e and define the probability of a dangerous failure per hour, for example PL d: 1/1,000,000 to 1/10,000,000. A PL d or e can be achieved using the solution proposed here.

Fig. 1 shows an exemplary structure of a touch screen input system 1 in a schematic representation. It comprises a touch-sensitive layer 5, a conductor loop layer 6, and visually perceptible buttons 2, of which three are shown on each layer by way of example.

The touch-sensitive layer 5 can be a resistive system, a surface-capacitive system, a projected-capacitive system, an inductive system, a wave- or sound wave-controlled system (Surface Acoustic Wave, SAW), an optical system, e.g. with an infrared light grating, or a dispersive signal technology system.

The actual display of the buttons can be done by a conventional display, which can be designed as an integrated layer with the touch-sensitive layer 5. Alternatively, the touch-sensitive layer 5 can only be a transparent layer, and a display layer can be arranged between the touch-sensitive layer 5 and the conductor loop layer 6.

The number of buttons 2 can be freely selected and depends on the intended use and the design options. It is conceivable that only one button 2 (e.g. machine start or buttons for opening or closing an injection mold) is protected by the second layer; it is also conceivable that a complete keyboard with up to 100 or more buttons is implemented. An example with two buttons 2 would be buttons 2 for moving machine axes or the like, where both circuits, i.e. those connected with an AND link, must be activated. Not all buttons on the touch screen have to be protected by the second layer. It is conceivable that some buttons can only be triggered by the touch-sensitive layer 5 or only by the conductor loop layer 6.

The system 1 further comprises an inductive input device 3, which is shown in Fig. 1 as an example as a pen. The inductive input device 3 can generate an alternating electromagnetic field 4, which can be detected by the conductor loop layer 6. The alternating field 4 is indicated in Fig. 1 by dashed circle segments, which are intended to symbolize a wave-like propagation.

Fig. 2 shows the input device 3 again, with the optional components pressure detection device 8 and fingerprint reader 9. The position of these optional components is also only schematic. For example, the fingerprint reader 9 can be mounted in such a way that when the input device 3 is used as a pen, the user's fingerprint can be read by the fingerprint reader 9. Alternatively, the fingerprint reader 9 can also be mounted in a place that is not touched during use, so that, for example, the input device 3 can be unlocked by a fingerprint before use. The same applies to the pressure detection device 8. This can be located near the tip, ie the part that is used to touch the touch screen, and can detect the pressure with which the tip is pressed onto the touch screen. Alternatively, the pressure detection device 8 can also be attached to another location on the input device 3, depending on the design of the input device 3. A differently designed pressure detection device can also be used to detect pressure exerted by the user on the input device 3, and thus confirm an intentional actuation of a button 2.

The input device 3 can, for example, be a glove with which the touch screen is operated.

Energy is required for the induction function of the input device 3. The input device can obtain this energy via a cable or have a built-in or replaceable energy storage device (for example a rechargeable battery or battery). The energy storage device can be rechargeable and can be charged, for example, by an induction charging device. This induction charging device can be installed, for example, in or on a storage device in which or on which the input device 3 is kept when not in use. The input device 3 can also be supplied with energy directly by induction, which it receives, for example, from an induction coil installed in the touch screen input system 1.

Regardless of the type of energy supply, the input device 3 can comprise a securing device, such as a wire or a cable, with which it is or can be secured to a specific location. This can ensure that the input device 3 is not lost.

The system 1 also includes a computing device 7. The computing device 7 can be installed in the screen part of the system 1, but the computing device 7 can also be an independent computer to which the signals from the components of the system that display the screen are fed. The computing device 7 can also refer to the part of a machine to be operated that carries out a control function, i.e. the controller, for the machine. The touch-sensitive layer 5 and the conductor loop layer 6 are shown offset from one another in Fig. 1 for better comprehensibility, but they are usually located on top of one another. The touch-sensitive layer 5 is located above the conductor loop layer 6, ie closer to the person operating it.

However, it is also conceivable that the conductor loop layer 6 covers only a part of the touch-sensitive layer 5 in order to secure only the part of the touch-sensitive layer 5 corresponding to the conductor loop layer 6 by a second positioning of the input device 3.

Fig. 3 shows a schematic flow chart based on which the touch screen input system 1 and the input method 100 therefor will now be described. Optional features are shown in dashed lines.

First, in step 110, an actuation of the touch screen input system 1 with the input device 3 is detected by the touch-sensitive layer 5. As already described, the touch-sensitive layer 5 can be constructed according to a known functional principle. In step 120, the touch-sensitive layer 5 also detects first position information of the input device 3, i.e. the location at which the input device 3 touches the touch-sensitive layer 5.

In step 130, the conductor loop layer 6 detects the alternating electromagnetic field 4 of the input device 3 and determines second position information of the input device 3 by comparing induction signal strengths. In this case, the conductor loop layer 6 measures induction signal strengths at the individual conductor loops of the conductor loop layer 6 and determines the position of the input device 3 by comparing them.

It should be noted that steps 110, 120 and 130 can occur in any order and even simultaneously.

In the next step 140, the computing device 7 checks whether the first position information, the second position information and the button position match. Here, the first position information is received from the touch-sensitive layer 5 the second position information from the conductor loop layer 6, and the button position from the unit that controls the representation of the buttons 2 on the display layer or the touch-sensitive layer 5 with display function.

It should be noted that the positions can be aligned with a certain tolerance in order to compensate for measurement inaccuracies. The tolerance can be set depending on the components used, the input device 3 used, the size of the buttons 2 and/or empirical values.

If the three positions match, the button is triggered in step 150 when the touch screen input system 1 is activated. When button 2 is activated, the function or command linked to button 2 is transmitted to the corresponding counterpart. If the touch screen input system 1 is activated, i.e. touched by the input device 3, and the touch position indicated by the first position information can be verified twice, i.e. by the second position information and the known button position, the function or command linked to the touched button 2 is also triggered.

Optionally, one or more of the buttons can each have a fixed position on the touch screen input system. These buttons can then also be printed on, for example, or marked with stickers, so that if the display device or function fails, a button 2 can still be found and pressed. This can also prevent burn-in, because while normal buttons can be displayed at different positions at certain intervals to prevent burn-in, this may not be possible or permitted for safety-relevant functions.

The input device can optionally modulate additional input device information onto the electromagnetic alternating field in a step 105, which can be carried out before step 110. This means that the alternating field 4 can transmit additional information that can be determined and evaluated by the computing device 7. The computing device 7 can then make the triggering of the button 2 dependent on whether the transmitted additional Input device information meets predetermined criteria. The criteria can be defined for each button 2 or for the entire operation of the touch screen input system 1.

The modulation can be incorporated into the alternating field 4 as angle modulation, as amplitude modulation, as modulation methods derived therefrom or as pulse modulation.

The additional input device information can be, for example, a device ID of the input device 3. This allows different input devices 3 to be assigned different authorizations. For example, a specific input device 3 may be required to be able to perform a specific function, e.g. starting a maintenance mode. It is also conceivable that different input devices 3 are required for several machines at the same location, for example a first input device 3 for a first machine and a second input device 4 for a second machine.

The additional input device information can also relate to the user if the input device 3 is assigned to a specific user. This can be used, for example, to store which user performed which function at which time. Several users or input devices 3 can also be grouped together, and the authorization to execute various buttons can depend on the respective group.

The authorization of an input device, for example to start a special operating mode or to press a special function button, can also depend on a login process that the user has previously carried out. This means that although there are a number of input devices that are basically authorized, after a user has logged in to a machine, only the input device used by this user for the login is authorized and this authorization can only be revoked by using the authorized input device or by another authorized user action. Input devices can each have a unique identifier that would be temporarily registered as this user's input device during the login process for the duration of the login. This means that separate rights management for the input devices is not necessary, and instead the rights of the The advantage here is that a lost input device can be easily replaced and mixing up input devices has no negative consequences. In addition, a lost or stolen input device does not enable an unauthorized third party to operate the system.

To further increase security, additional identification or authentication may be required in addition to the input device, for example through a key, a magnetic or RFID card, a smart device such as a wearable or a mobile phone, TAN tokens, biometric procedures or similar.

The exclusive authorization of the input device of the logged-in user increases security, particularly in connection with so-called special operating modes of a machine. Special operating modes can be, for example, maintenance in which otherwise effective protective measures are deactivated, such as light barriers, protective doors, protective plates or screens. Testing, setup or adjustment operations could also be a special operating mode. As long as a user is logged in to the machine, has activated such a special operating mode and is carrying his input device with him, no other person can trigger safety-critical machine functions (e.g. activation of drives, tools or energy sources or deactivation of brakes or holding devices) or authorize any other input device. This protects the logged-in user while he carries out repairs, inspections, adjustment work or similar actions on parts of a large machine or system that may not be visible to other people. However, the user who is logged in and carrying out maintenance work can trigger such safety-critical functions with his input device at any time and without any hassle, i.e. without having to lock the machine every time he leaves the control panel and then unlock it again. This significantly simplifies the temporary exclusive assignment of operating authorization to exactly one user, thereby increasing user acceptance and improving safety.

The additional input device information may also indicate the actuation of a button on the input device 3, or the input of information via other means on the input device 3. For example, an input device 3 could have a setting wheel to navigate through menu structures to scroll through the different buttons 2 in response to the operation of the setting wheel.

In addition or as an alternative to the methods just described, the input device 3 can also transmit the additional input device information to the touch screen input system 1 via another communication path. Examples of this are Bluetooth, network communication (LAN, WLAN), infrared, shortwave radio and NFC.

It may also be a criterion that additional input device information identifying a user or an input device 3 is transmitted at all.

Furthermore, the position information confirmed three times by the system 1 can also be confirmed by a fourth device. This can be, for example, a visual detection device, such as a camera, an infrared camera or the like, or an acoustic detection device, such as a microphone, by which a voice input by the user that corresponds to the button 2 to be triggered is detected. This fourth device can also determine the identity of the user if necessary, and the buttons can be activated, deactivated or adapted accordingly.

The system 1 can also, as soon as an input device 3 is detected (by the conductive loop layer 6 or, in the case of the further communication paths, by the corresponding components of the touch screen input system 1), process or forward this additional input device information so that the buttons that are not available for the current user or the current input device 3 are hidden or otherwise marked as unavailable.

The input device 3 can also include further functions. For example, the input device 3 can include a pressure detection device 8, which is designed to detect the pressure with which the input device 3 is pressed onto the touch screen input system 1. The additional input device information can then include the detected pressure. On the one hand, this can create an additional level for functions, because a button can have a different command or function assigned to it when it is lightly pressed than when it is hard pressed.

In addition, an additional level of security can be introduced and constant pressure over a long predetermined period of time can be interpreted as a failure of the input device or the input device is considered to be discarded.

In addition, the touch-sensitive layer 5 can also be equipped with a pressure sensor, and the two determined values can be checked for agreement as an additional safety function.

The input device 3 can also alternatively or additionally comprise a fingerprint reader 9 and the additional input device information can comprise a read fingerprint. The fingerprint reader 9 can be attached in a location where a user's finger would rest during conventional operation. However, the fingerprint reader 9 can also be attached in a location that does not allow the fingerprint to be read during use. In this case, the input device 3 must be activated before use. It may also be necessary to use the fingerprint reader 9 before a particularly critical operation in order to obtain authorization to carry out the operation.

Alternatively or additionally, the input device 3 may have stored identification information, and the additional input device information may comprise the identification information, as previously described.

A further embodiment is a computer program product comprising instructions which, when executed by a computer, cause the computer to perform one of the methods set out above.

Another embodiment is a computer-readable medium on which the computer program product is stored.

The embodiments show possible variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated variants the same is limited, but rather various combinations of the individual design variants are possible.

The scope of protection is determined by the claims. However, the description and the drawings must be used to interpret the claims. Individual features or combinations of features from the different embodiments shown and described can represent independent inventive solutions in themselves. The task underlying the independent inventive solutions can be taken from the description.

All information on value ranges in the description in question is to be understood as including any range and all subranges thereof, e.g. the information 1 to 10 is to be understood as including all subranges starting from the lower limit 1 and the upper limit 10, i.e. all subranges start with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Finally, for the sake of clarity, it should be noted that, in order to better understand the structure, some elements have been shown not to scale and/or enlarged and/or reduced.

reference symbol list

touch-screen input system

buttons inductive input device electromagnetic alternating field touch-sensitive layer

conductor loop layer

computing device

pressure detection device

fingerprint reader

input procedure

Modulating additional input device information

recording an actuation

collecting initial position information

capturing second position information

Checking the consistency of the position information

Determining the additional input device information

Triggering the button

Claims

patent claims 1. Touch screen input system (1) which has at least one visually perceptible button (2) at at least one position, comprising: an active, inductive input device (3) which is designed to generate an alternating electromagnetic field (4); a touch-sensitive layer (5) which is designed to detect actuations of the touch screen input system (1) by the input device (3) and first position information of the input device (3); a conductor loop layer (6) which is designed to detect the alternating electromagnetic field (4) and to determine second position information of the input device (3) by comparing induction signal strengths; and a computing device (7) which is designed to check whether the first position information, the second position information and the button position match and, if so, to trigger the button (2) when actuated by the touch-sensitive layer. 2. Touch screen input system (1) according to claim 1, wherein each of the at least one button (2) has a fixed position on the touch screen input system (1). 3. Touch screen input system (1) according to claim 1 or 2, wherein the input device (3) is further configured to modulate additional input device information onto the alternating electromagnetic field (4); and the computing device (7) is further configured to determine the additional input device information from the detected alternating electromagnetic field (4) and to trigger the button (2) only if the additional input device information meets criteria stored for the button (2). 4. Touch screen input system (1) according to claim 3, wherein the input device (3) comprises a pressure detection device (8) which is designed to detect the pressure with which the input device (3) is pressed onto the touch screen input system (1), and the additional input device information comprises the detected pressure; the input device (3) comprises a fingerprint reader (9), and the additional input device information comprises a read fingerprint; and/or the input device (3) has stored identification information, and the additional input device information comprises the identification information. 5. Touch screen input system (1) according to one of claims 3 or 4, wherein one of the criteria stored for the button (2) comprises identification information of a predetermined input device (3) from a set of several similar input devices (3), wherein the identification information of the predetermined input device (3) is registered in the stored criteria by a user using the specific input device (3). 6. Touch screen input system (1) according to one of claims 1 to 5, wherein the touch-sensitive layer (5) is further configured to detect direct actuations of the touch screen input system (1) by an operator and third position information of the direct actuation; and the computing device (7) is further configured to detect a first group of buttons (2) which can only be activated by an input device (3) are to be triggered, to issue a message indicating the need for an input device (3) for actuation; and for a second group of buttons (2), which are to be triggered even without an input device (3), to check whether the third position information and the button position match, and if so, to trigger the button (2) upon direct actuation detected by the touch-sensitive layer. 7. Input method (100) for a touch screen input system (1) according to one of claims 1 to 6, comprising: Detecting (110) an actuation of the touch screen input system (1) with the input device (3) by the touch-sensitive layer (5); detecting (120) the first position information of the input device (3) by the touch-sensitive layer (5); Detecting (130) the alternating electromagnetic field (4) through the conductor loop layer (6) and determining (135) the second position information of the input device (3) through the conductor loop layer (6) by comparing induction signal strengths; Checking (140), by the computing device (7), whether the first position information, the second position information and the button position match; and if they match, triggering (150) the button (2) when the actuation of the touch screen input system (1) is detected. 8. Input method (100) according to claim 7 for a touch screen input system (1) according to one of claims 1 to 6, further comprising: Modulating (105), by the input device (3), additional input device information onto the alternating electromagnetic field (4); and Determining (145), by the computing device (7), the additional input device information from the detected electromagnetic alternating field (4); wherein the triggering (150) of the button (2) only occurs if the additional input device information fulfills criteria stored for the button (2). 9. Input method (100) according to claim 8 for a touch screen input system (1) according to one of claims 1 to 6, wherein: the additional input device information includes the pressure with which the input device (3) is pressed onto the touch screen input system (1); the additional input device information includes a fingerprint; and/or the additional input device information includes identification information of the input device (3). 10. Input method (100) according to claim 7 or 8 for a touch screen input system (1) according to one of claims 1 to 6, wherein: one of the criteria stored for the button (2) comprises identification information of a predetermined input device (3) from a set of several similar input devices (3), wherein the identification information of the predetermined input device (3) was registered in the stored criteria by a user using the specific input device (3). 11. Input method (100) according to one of claims 7 to 10 for a touch screen input system (1) according to one of claims 1 to 6, further comprising: Detecting a direct actuation of the touch screen input system (1) by an operator through the touch-sensitive layer (5); detecting (120) third position information of the direct actuation by the touch-sensitive layer (5); and for a first group of buttons (2) that can only be triggered by an input device (3), Outputting a message indicating the need for an input device (3) for actuation; and for a second group of buttons (2) that can also be activated without an input device (3), Checking (140), by the computing device (7), whether the third position information matches the button position; and if there is a match, triggering (150) of the button (2) when direct actuation of the touch screen input system (1) is detected. 12. Computer program product which can be loaded directly into a memory of a programmable control device of a touch screen input system (1), with program code means to carry out all steps of an input method according to one of claims 6 to 10 when the program product is executed on the control device.