Sealed front panel

Abstract

The invention relates to a sealed human machine interface (HMI) device (20) like a vehicle dashboard instrument, with an instrument housing (23) that is hermetically sealed with at least IPx4 protection level or higher, comprising a control and display front panel (22). The front panel (22) comprises at least one area (26) that is optically transparent for visual light and a visual display (26) behind the transparent area (26) and an operating panel (28) outside of the instrument housing (23), comprising at least one physical control element (24) with a physically movable or deformable portion (24a, 24b). According to the invention an electro-optical distance measurement proximity sensor (30) is arranged inside the instrument housing (23), which is arranged and configured to measure a distance information (42) from the proximity sensor (30) towards a backside of the physical control element (24) outside the instrument housing (23). This measuring is done through a sensing portion of the front panel (22) behind the physical control element (24) that is optically transparent for the electro-optical distance measurement proximity sensor (30). An evaluation electronic (32) is configured to determine and provide at least one switching state of the control element (24) based on the distance information (43) from the proximity sensor (30).

Description

[0001] Sealed front panel

[0002] The invention related to a sealed human machine interface (HMI) device according to the preamble of claim 1, for example to a vehicle dashboard instrument and to a method for determining a manual operation of a physical control element of an operating panel arranged at an outside of an instrument housing of a human machine interface device according to claim 14 and to a computer program product for operating such an HMI device.

[0003] Human machine interfaces (HMI) are used to operate or control devices and machine by human operators. Such operating comprises indicating or outputting of an information required for operating the device - like a state of the device or its environment, measurement values, operating conditions, a technical parameter, an actual value or a value to be set, etc. Such operating can further comprise modifying or inputting of an information required for operating the device - like a entering a command, setting a desired value, changing a parameter, configuring a setup, etc. preferably related to the information that is optically indicated on the HMI. Examples are control panels, operation panels, dashboards, control consoles, user interfaces, etc. A typical example of an HMI can comprise a visual or optical indication unit for output, like a visual display, screen or gauge and at least one input element like a button, switch, lever, knob, etc. This invention concerns primarily the physical HMI and its usage, not the pure software for a graphical HMI design or a virtual HMI.

[0004] An aspect with HMIs is, that the HMI device or unit often needs to be protected from environmental conditions like dirt, water, moister, etc. There are standardized protection levels which are defined for classifying devices in this respect. Widely used is the so-called Ingress Protection Code or IP-Code defined by the International Electrotechnical Commission (IEC). It comprises the "IP" prefix followed by a first number indicating the solid particle protection and a second number indicating the liquid ingress protection. An x instead of a number means that this value is technically not relevant or required to be defined. For example, IP67 means 6=being dust-tight and 7=can be emersed in water up to lm. The meaning of the numbers is defined by IEC. Another example of a definition is the NEMA-rating of enclosures in USA.

[0005] The visual indication of the HMI can simply be protected by a continuous front panel or front glass that is at least in some sections optically transparent and which can be affixed (e.g., sealed, glued, ...) to the housing to achieve a tight housing.

[0006] The input element(s) of the HMI is are complex to seal. Touchscreen and capacitive sensing can be a solution, but in many instances - in particular according to the present invention, it is desired to have real physical input elements, like buttons, knobs switches to be pressed or operated by a human. Those provide tactile sensation, they can also be found or located tactile by hand, and they provide some tactile feedback.

[0007] Providing a physical input element like a key or button classically means that some kind of hole in the housing has to be provided for passing through a portion of a classical button or that there is some soft / thin deformable portion in the sealing of the housing itself that has to be provided, like a plastic foilkeyboard or membrane keypad.

[0008] Touchless or touching capacitive or resistive switches or touchscreens are easier to be accidentally operated by a passing by object or finger, whereas a physical input element needs actual physical actuation, pressure or force. The present invention is not related to a direct sensing of a finger of the operator. For example, known capacitive or optical sensing does not provide physical buttons and is therefore not related. In many technical areas such buttonless operation is undesired, e.g., in harsh environments with dirt, moister, water, snow, etc. or when operated with gloves, etc. Another known option is to use magnetic sensors through the housing, but in many instances the therefore required magnetic element are not desirable or result in complicated technical solutions. Also, redirection of optical paths by mirrors, total-reflection, result in complex technical systems which are often not robust enough. Some examples of known attempts to provide a sealed housing without holes which is still providing physical buttons can e.g., be found in DE102006043619, US2022359141, WO2019122913A1, W02022010331A1, US2005088417.

[0009] The known solutions all result in drawbacks at one end or the other. Objects like robustness, accuracy, ease of implementation, low part count, sealing levels achievable, usability in harsh environments, durability, service and replacement, reliability, calibration, safety, error detection, and in particular their combination are examples of deficits of the known solutions in providing an HMI.

[0010] It is therefore an object of the present invention to provide an improved HMI interface - in particular by a physical design but also in view of evaluation of information, functionality, safety, etc. and methods related to this new physical design. Preferably to overcome one or more of the above-mentioned deficits. In particular to provide an improved, fully sealed HMI device with physical buttons. For example, a vehicle dashboard instrument with some kind of visual display and with physical buttons to operate it.

[0011] Those objects are achieved by the features of the independent claims. Further advantageous aspects and additions are provided by the features of the dependent claims, in the figures and in the description.

[0012] According to the invention, a sealed human machine interface (HMI) device is provided. For example, a vehicle dashboard instrument that is configured to be mounted at a vehicle instrument panel.

[0013] It is in particular designed to be capable to be operated in harsh environment with dirt, liquid and / or moisture. It comprises an instrument housing that is sealed against liquid or physical or gaseous element ingress. For example, with at least IPx4 IEC protection level, but preferably up to IPx7, IPx8 or IPx9 protection level. This protection is provided at least at the frontside of the HMI device, where it its operated, but preferably entirely, between frontside and backside. It is preferably hermetically sealed or in other words fully encapsulating its inner electronics and components from the environment.

[0014] The instrument housing comprises a control and display front panel at its frontside. By this front panel the HMI device is operatable by a human operator, in particular providing information to the operator and receiving control information from the operator.

[0015] The front panel comprises at least one area that is optically transparent for visual light, in particular a front glass, and a visual indication element inside the instrument housing, behind the transparent area of the front panel. For example, a visual indication element in form of a visual display, a screen like an LCD, TFT, or the like, a gauge, one or more LEDs, etc. Thereby an operator can see an actual state or information of the HMI-device or of a device connected thereto. Alternatively or additionally the information can also be provided in acoustic or haptic form.

[0016] The front panel also comprises an operating panel outside of the instrument housing, comprising at least one physical control element. This physical control element has a physically movable or deformable portion that is configured to be actuated by applying a force or pressure, for example by a human operator respectively his fingers. Thereby an operator can influence an actual state or information of the HMI-device or of a device connected thereto.

[0017] According to the invention, an electro-optical distance measurement proximity sensor is arranged inside the instrument housing. This electro-optical distance measurement proximity sensor is arranged and configured to measure a distance information from the proximity sensor inside the instrument housing towards a backside of the physical control element outside the instrument housing. This distance information measurement is established through the front panel, in particular through a sensing portion of the front panel behind the physical control element, which sensing portion is optically transparent for the electro-optical distance measurement proximity sensor. This means that an optical measurement of a distance value in a distance measuring unit is established from the inside of the housing through the front panel to an (backside-) area of the physical control element that is facing the front panel. The front panel can therein preferably be a one-piece item like a front glass for both the visual indication element and the operating panel but can also be separated for those two in another embodiment.

[0018] The HMI device also comprises an evaluation electronic that is configured to determine and provide at least one switching state of the control element based on the distance information from the proximity sensor. According to this determined switching state, the HMI-device and / or a thereto connected device can be operated, e.g., comprising adjusting an information provided by the visual indication element and / or sending a command or information to a device by a wired or wireless connection.

[0019] Preferably, the evaluation electronic is configured to adjust a function or a provided value of the visual indication element based on the determined state of the control element. Additionally or alternatively, the evaluation electronic is configured to provide a signal for controlling a machine or a portion of a vehicle based on the determined state of the control element. Thereby, human operator can operate the HMI-device and / or another device in connection with it.

[0020] Preferably, the electro-optical distance measurement proximity sensor comprises a laser light source transmitting pulses of a directed (e.g., collimated, zero or low divergence) light beam of a defined wavelength towards the backside of the control element - through the front panel, and the electro-optical distance measurement proximity sensor further comprises a photo-receiver (e.g. a photodiode) receiving backscattered portions of the light beam of the defined wavelength from the backside of the control element - through the front panel. A distance measuring and an evaluation electronic is configured to determine the distance value information. In particular a time-of-flight distance measuring and an evaluation electronic is evaluating a distance value according to a time of flight of the pulses from the laser light source through the front panel to the backside of the control element and back to the photoreceiver. The transmitted and received light beam through the front panel is therein preferably coaxial or at least substantially coaxial. The distance information is in particular determined with a distance resolution of about 1mm, preferably less than 1mm. Thereby, an actual distance value of the distance towards the device-inner side of the physical control element can be determined, which distance value depends on the actuation state of the physical control element, like its position, movement or deformation.

[0021] Preferably, the electro-optical distance measurement proximity sensor is configured to emit a directed light beam from a fixed, same location into a fixed same direction and to receive the light at fixed same location, in particular independent of the distance that is measured. This provides a simple setup and placement of the proximity sensor and its usage independent of the actual distance of the sensor relative to the front panel or control element along the light beam direction.

[0022] Preferably, a measurement direction of the electro-optical distance measurement proximity sensor is substantially perpendicular to the front panel. For example, the direction of the light beam from the laser light source mentioned before is fixed about orthogonal to the front panel. Thereby the evaluation of the control element can be located right behind the control element. The absolute distance from the electro-optical distance measurement proximity sensor to the front panel can be defined as advantageous in view of the design of the inner electronics of the housing. This also helps to avoid reflections from the front panel. The front panel can also comprise an anti-reflection coating on its inner and / or outer side to avoid or reduce measurement light being reflected from the front panel.

[0023] Preferably, the electro-optical distance measurement proximity sensor is measuring through an optically transparent area of the visual indication element. In an embodiment, the measurement light of the electro-optical dis- tance measurement proximity sensor can be passing through the visual display and the front panel. Thereby, the sensor can also be arranged behind a display and / or the physical control element can be located inside the viewing area of the display.

[0024] The distance measurement proximity sensor can therein be arranged substantially directly behind the front panel, in particular from almost zero to 10 mm. The distance measurement proximity sensor provides a measurement distance resolution preferably below 1 mm, in particular of 0,1 mm or below 0,1 mm.

[0025] Due to the collimated and (de facto) coaxial beam guidance of the measuring light, the sensor can also be mounted at a substantially random, in particular greater distance behind the control element. In particular, with a distance of more than 1 cm between the sensor and the control element, especially from 1 cm to 10 cm, in special designs possibly even more than 10 cm. This facilitates, for example, the design of the device and the arrangement and mounting of the sensor-carrying circuit boards in the housing, which can also be done at the backside of the device, for example. On the other hand, such a spaced arrangement of the sensor can also avoid or reduce the negative influence of any stray light that may enter through the front panel, for example.

[0026] In one embodiment, also a kind of aperture in the form of a hole can optionally be provided in an element arranged between the sensor and the control element, through which hole the measuring light is guided, which can also avoid stray light effects and / or the measurement can thereby be made more specifically on a well-defined area the rear of the control element.

[0027] In particular, the distance measurement proximity sensor can therein be configured in its evaluation electronics to only evaluate measurement values in a distance range at least proximately corresponding to the actual distance to the control element - respectively to ignore measurements from distances below and / or above a certain threshold, in particular unreasonably above or below the control element distance, like e. g. the distance of an aperture as mentioned above.

[0028] Another option therein is, that when the measurement light of the electro- optical distance measurement proximity sensor is passing through the visual indication element - e.g., in form of a TFT or LCD screen or the like - visual indication element can be configured to let the measurement light pass though or not. Thereby, e.g., the physical control element can be activated or deactivated according to the configuration of the visual indication element in the area of the physical control element - by either letting the measurement light pass towards the control element or - by blocking it and thereby hindering the control element to be evaluated. For example, this can provide an additional security level by two ways of hindering a button to be used -the software evaluation and the hardware blocking of the light. Such an embodiment also allows to locate the electro-optical distance measurement proximity sensor (and the PCB carrying it) to be located in a second stage or layer behind a display, which allows mor flexibility in device design.

[0029] Preferably, the electro-optical distance measurement proximity sensor is mounted on a printed circuit board (PCB) inside the instrument housing, in particular wherein the printed circuit board is arranged substantially parallel to the front panel and the electro-optical distance measurement proximity sensor is measuring substantially perpendicular to it. In one embodiment, this same PCB can also carry the visual indication element (like a display, LEDs, ...) or in another embodiment it can be a PCB behind the visual indication element (like a display mounted to the front panel or housing).

[0030] Preferably, the movable or deformable portion of the control element is movable substantially perpendicular to the front panel. For example, an operator can press a button towards the front panel as he is used to from classical through-hole button designs or foil-buttons.

[0031] In one embodiment, the rear side of the control element - which is impinged with the measuring light - is designed (e. g. corresponding material, color, optionally also coating) in such a way that at least a part of the measuring light from the sensor (preferably a significant part of at least 20%, preferably more than 50%) is scattered back to the sensor.

[0032] In a preferred embodiment this rear side of the control element is particularly non-mirroring or non-mirror-reflective. This makes it possible, for example, to avoid or reduce directed reflection of the measuring light (according to the angle of incidence / angle of reflection principle), in which the direction of the returning light could direct (at least partially) away from the sensor or its optical receiving element. For example, when the control element is operated with a slight angular tilt or in a non-parallel manner.

[0033] Preferably, the front panel is a single peace throughout the whole front panel, also behind the control element. For example, a front glass (which can mean a real glass or artificial-glass or plastics) which is persistent and unperforated. Preferably the front panel is also solid, in particular and nondeformable when operating a control element. Thereby, a rigid, solid and robust HMI-device with high IP-protection levels can be established.

[0034] Preferably, the control element is a button or a switch that is manually movable or deformable in front of the front panel, e.g., by an operator of the human machine interface device. The electro-optical distance measurement proximity sensor is arranged and configured to measure the movement or deformation of the control element in form of a distance information substantially perpendicular to the front panel toward an inner side of the button or a switch that is facing the front panel.

[0035] Preferably, the physical control element is attached to the front panel or attached in front of the front panel. For example, glued or vulcanized directly to the front panel or applied with holding members arranged in front of the front panel. Such a holding members and / or its control elements can also be replaceable in case of wear. The holding member can be an arrangement comprising one, preferably more control elements and being attached to the front panel. Thereby, an easy production with low part count can be established and / or repairability can be improved.

[0036] Preferably, the physical control element is in the form of a button with an at least partially deformable dome shape that comprises elastic material, that can be actuated substantially perpendicular to the front panel. Preferably, the physical control element is configured as a rubber-dome or Rubber-Key-Pads or as a snap dome or a tactile metal dome or a dome spring, attached outside to the front panel. Thereby, a change in the measured distance can be established when operating the control element, while keeping the design simple.

[0037] Preferably, the physical control element is in the form of a switch providing at least two switching states of a switch-element that is movable substantially perpendicular to the front panel when actuating the switch. In an embodiment, the switching states can be bistable, which means the switch is keeping its position after one actuation until another actuation occurs.

[0038] The invention also relates to an according method for determining a manual operation of a physical control element of an operating panel arranged at an outside of an instrument housing of a human machine interface device. Therein, the manual operation of the control element provides a movement or deformation of the physical control element perpendicular to an unperforated front panel of the instrument housing.

[0039] The method comprises an electro-optical distance measurement through an optical transparent portion of the front panel from an inside of the instrument housing towards a backside of the physical control element determines a distance value measurement. This is measured by a laser distance measuring sensor that operates perpendicular through the front panel.

[0040] The method then is determining an operation state of the physical control element according to the distance value measurement - respectively determines the operation of the control element according to a change of the continuously measured distance value. The invention also relates to a method for providing a hermetically sealed housing for an electronic control unit of a human machine interface (HMI) device. This HMI device comprises at least one physical control element with a manually movable or a deformable portion that is configured to be actuated by an operator of the human machine interface device from its frontside. The method according to the invention is established by optically measuring a distance from the inside of the housing through an at least sectional optically transparent, solid and rigid front panel towards a backside of the physical control element. The measurement been preferably perpendicular to the front panel. The Method is determining a distance value difference by the movement or deformation of the physical control element, and determining and providing a state of the physical control element according to the distance value difference. This can be used for controlling a function of the human machine interface device or of an external device according to the state of the physical control element.

[0041] In other words, the invention is related to display instruments with buttons - especially to buttons on instruments, displays on vehicles, vessels, machineries in maintain, agriculture and so on. Its scope is to provide simplified, robust switch / button on display instruments, without requiring any holes in the housing or support material. This is solved by an unperforated front panel behind the buttons and optically measuring a distance from the inside of the housing thought the front panel to the inner side of the button and deriving a switching state of the button depend on the distance which changes when the button is pressed (towards the front panel).

[0042] Respectively, the invention relates to a method for establishing a sealed interface device with a visual indication display and at least one mechanical control element. The interface device comprises an at least sectional optically transparent, solid front panel and is configured to form a hermetically sealed housing, in particular configured dust and / or liquid tight. The method uses an optical laser-measuring of a distance value from the inside of the housing, passing through an optically transparent section of the front panel towards a (front panel facing) backside of a movable or deformable portion of the mechanical control element that is attached in front of the front panel. And a determining of a switching state of the control element according to a change in the distance value. The distance measurement is in particular established by an optical time of flight laser distance measuring proximity sensor measuring the distance value substantially perpendicular through the front panel.

[0043] The invention also relates to a computer program product stored on a computer readable storage media comprising program code configured to determine a switching state of a control element attached outside of a hermetically sealed housing of an HMI-device. The program code is configured to interact with an electro-optical distance measurement proximity sensor to determine a series of distance measurement values from the inside of the housing through a front panel of the housing to a backside of the switching element. The program code then derives a change of the switching state when the distance measurement values are changing.

[0044] Further advantages, features and details of the invention are shown in the following description, in which embodiments of the invention are described with reference to the drawings.

[0045] The list of reference signs, as well as the technical content of the patent claims and figures, forms part of the disclosure. The figures are described in a coherent and comprehensive manner. Identical reference signs indicate identical components, reference signs with different indices indicate components with identical or similar functions.

[0046] It is shown:

[0047] Fig. 1 a first example of an embodiment of a HMI device according to the invention,

[0048] Fig. 2a a first detail view of an embodiment with an unactuated button, Fig. 2b a second detail view of an embodiment with an actuated button, Fig. 3 a second example of an embodiment of a HMI device according to the invention, Fig. 4a a third detail view of an embodiment with an unactuated button, Fig. 4b a fourth detail view of an embodiment with an actuated button, Fig. 5 a sixth detail view of an embodiment with an unactuated button, Fig. 6 an example of an embodiment of a value distance measurement, Fig. 7a a third example of an embodiment of a HMI device according to the invention,

[0049] Fig. 7b a font view of the third example of an embodiment of an HMI device from Fig. 7a.

[0050] Fig. 1 shows a cross-sectional cut-view of a first embodiment of a human machine interface (HMI) device 20 according to the invention. It comprises a housing 23 that is sealing its inside from environmental conditions like dirt and / or liquid to protect the inner components, electronics, etc. The device 20 has a front panel 22 shown right in the figure and a backside 21 shown left. The backside or housing shell 21 can comprise mounting gear, electrical connections, etc. The front panel 22 is configured as an interface configured for providing a visual output and receiving input to / from a human operator. It comprises a visual indication element 26 such as a graphical or numerical display or screen, LEDs, a gauge, etc. which is visible through an area of the front panel 22 that is configured to let visible radiation pass, like a transparent area 25, for example a front glass. The front panel 22 can also comprise regions where it is not transparent, can comprise graphical or textual information on it and can e.g., be made of real or artificial glass.

[0051] The front panel also comprises an operation panel 28 which comprises one or more physical control elements 24 like buttons, switches, knobs or the like at the outside of the housing 23. Those control elements 24 are configured to be operated by applying a force or pressure 41 - e.g., by a finger of the human operator - by which the physical control element 24 can moved or deformed, preferably substantially in a direction towards the front panel 22 as shown. According to the invention, the front panel 22 is also sealed behind the physical control element 24. The front panel 22 can be nonperforated, with no holes but e.g., a throughout front glass. The front panel 22 is also rigid, so that the front panel 22 itself is not substantially deformed when applying the force 41 required to operate the HMI-device 20. The front panel 22 is sealed to the housing 21, in this example circumferentially glued to the housing 21.

[0052] According to the invention, the control element 24 is evaluated by measuring a distance 42 from the inner of the housing 23, through the closed front panel 22, towards the backside of the control element 24. This is established by a distance measurement proximity sensor 31 in the housing, for example such a sensor like a VCNL36826S from Vishay or a functional equal chip that is mounted at a printed circuit board (PCB) 31 inside the housing 23. Some evaluation electronics, preferably also mounted to the same PCB is configured to derive an information of the state of the control element 24 according to the distance 42 measured respectively to a change of the distance 42 measured. This state can be a binary state like actuated / nonactuated. The state can also comprise information like how hard / far the button is pressed, e.g., adjusting a value slower or faster dependent on how much the button is de- formed / moved respectively how hard the control element is pressed.

[0053] Fig. 2a illustrates a detail view of a control element 24a in an unactuated state with no (or no sufficient) force 41a applied. The control element 24a is in home or rest position, resulting in a distance value 43a of the optical distance measurement 42a.

[0054] Fig. 2b illustrates a detail view of a control element 24b in an actuated state with sufficient force 41b applied to operate the control element 24b. In the shown example, the control element 24b is deformed by the force 41b, resulting in a reduced distance value 43b of the optical distance measurement 42b from the sensor to the backside of the deformed / moved control element 24b through the front panel 22.

[0055] Fig. 3 shows a cross-sectional cut-view of a second embodiment of a human machine interface (HMI) device 20 according to the invention. It again com- prises a housing 23 that is hermetically sealed, protecting its inside from environmental conditions. In this example, an LCD, or TFT or another optical display 27 is shown inside the housing 23 which is visible through a transparent area 25 of the front panel 22. According to the invention there is also the optical distance measurement proximity sensor 30 and its evaluation unit 32 as described before on a PCB 31. In this embodiment, the distance measuring light 42 is not only passing through a transparent region of the front panel 22 towards and back from the backside of the physical control element 24 applied to the front of the front panel 22. The distance measuring light 42 is also passing through the display 27. For example, there can be a hole in the backlight section of the display 27 allowing the measurement light 42 to pass (instead of the backlight-light). This allows e.g., an integration of the physical control element 24 in the HMI display 27 - not only besides or at the border, but also at any random position within the area of the display a desired. This e.g., allows to display configurable a labeling or indication of the physical control element 24 below or around it, in particular requiring only a single display.

[0056] In a special variant of such an embodiment, the control element 24 can also be (back-) illuminated by the display 27, as the area for the distance measuring light 42 can be smaller than the control element 24 area, e.g., a few square millimeters. The display 27 at or around this area can provide an illumination of the control element 24, in particular in a configurable way with respect to brightness, color, etc. as the display provides.

[0057] As in all embodiments, preferably, a non-visual wavelength of the measurement light of the distance measurement can be used. In particular in embodiments with a back illumination of the control element through the front panel by the display or by an LED, whereby illumination and measurement do not interfere. Another option is to shortly turn of or dim illumination during a distance measuring timeslot.

[0058] In a special variant of this embodiment, the display 27 can be controlled to let the measuring light 42 pass through or not - as it regularly does with the backlight. By blocking the measuring light, the control element 24 can be deactivated, by letting it pass it can be activated. Thereby an additional hard- ware-disable of a control element 24 can be established.

[0059] In Fig. 4a another detail view of a control element 24a in an unactuated state with no (or no sufficient) force 41a applied is shown - similar to Fig. 2a. The control element 24a is in home or rest position, resulting in a distance value 43a of the optical distance measurement 42a.

[0060] In Fig. 4b another a detail view of the control element 24b from Fig. 4a is shown in an actuated state with sufficient force 41b applied to operate the control element 24b - similar to Fig, 2b. In the shown example, the control element 24b, in particular the part that is distance measured is not deformed, but moved by the force 41b, resulting in a reduced distance value 43b of the optical distance measurement 42b from the sensor to the backside of the de- formed / moved control element 24b through the front panel 22.

[0061] Fig. 5 shows another embodiment, where there is a snap dome or click-dome as control element 24 or part of it, which is attached to the outside of the front panel 22. The inside of this dome is optically distance measured through the close front panel 22 by a distance measurement proximity sensor 30 in the PCB 31 inside of the housing 31. When the dome is actuated, it results in a distance change 42 in-between pressed and released position that is evaluated to determine a switching state.

[0062] According to the invention, the control elements 24 of the operating panel 28 can also comprise other additional mechanical components, e.g., for combining them, making them bistable or exclusive or the like and / or for assembly of an operating panel 28 comprising multiple control elements 24 and for fixing them outside the front of the front panel 22 to the housing 23.

[0063] A laser light source 50 is emitting a collimated laser beam 52 that is passing through the front panel towards a backside of the dome where the distance measuring light is backscattered and received by a photodiode 51 in the distance measurement proximity sensor 30. A distance evaluation electronics 53 is then evaluating the distance information the light has traveled forth and back to the back of the control element 24. For example, the distance can be evaluated according to a time of flight of light pulses.

[0064] Fig. 6 shows an example of a schematical view of a distance measurement proximity sensor 30 that can be used according to the invention with the laser 51 and the photodiode 51 and all the electronics 54,55 and computation equipment 53 for distance measuring in a small sized single package chip 30.

[0065] Fig. 7a illustrates a cross-sectional cut-view of a third embodiment of a human machine interface (HMI) device 20 according to the invention. It comprises a housing 23 that is sealing its inside from environmental conditions like dirt and / or liquid to protect the inner components, electronics, etc. The components and features indicated are the same or equal to the description of the other embodiments, but their arrangement and / or embodiment varies slightly. In particular, the control element 24 is configured as a flexible dome or rubber dome at the outside of the non-pierced completely throughout front panel 22. The shown different textures only indicate transparent and nontransparent sections of the front panel 22.

[0066] Fig. 7b illustrates a front view of an example of an embodiment of a human machine interface (HMI) device 20 according to the invention. It is showing the front panel 20 with a display area 25 / 25 for visual indication and the operating panel 28 comprising buttons 24 as physical control elements, e.g., form of rubber-domes attached to the outside of the front of the front panel 22.

[0067] Obviously for the person skilled in the art, the embodiments and approaches shown or described here in different figures can also be combined and interchanged differently than shown in the sense of the invention. Reference signs

[0068] Human machine interface device, HMI, vehicle dashboard instrument, Backside

[0069] Frontside, Front panel, HMI, Interface housing, instrument housing, inside control element, Button, knob, switch a / 24b Actuated I released control element front glass, transparent area, optical indication element, Display, Gauge, Sensor-transparent area or hole operating panel

[0070] Watertight sealing, Glue, welding, distance measurement proximity sensor, TOF-Sensor Electronics carrier, Printed circuit board, PCB Electronics, electrical circuit, evaluation unit Actuation, Pressure direction, force, operator-fingera / 41b Actuation I release, force I forceless

[0071] Optical distance measurement, light / laser beam, a / 42b Released Distance / actuated Distance measurement Distance value (determined by 30) a / 43b Distance value, actuated / released position Light emitter, Laser, LED

[0072] Light receiver, Photo-Sensor, Photodiode Light beam, Light path

[0073] Distance evaluation electronics, TOF-Evaluation a, 54b Transmission control and Electronics a, 55b Reception control and Electronics

Claims

Claims1. A sealed human machine interface (HMI) device (20), in particular a vehicle dashboard instrument, with• an instrument housing (23) that is sealed against liquid or physical or gaseous element ingress, preferably with at least IPx4 up to IPx8 or IPx9 protection level, in particular configured to be mounted at a vehicle instrument panel,• wherein the instrument housing (23) comprises a control and display front panel (22),• which front panel (22) comprises at least one area (26) that is optically transparent for visual light, in particular a front glass, and a visual indication element (26) inside the instrument housing (23) behind the transparent area (26) of the front panel (22), in particular a visual display, and• which front panel (22) comprises an operating panel (28) outside of the instrument housing (23), comprising at least one physical control element (24), with a physically movable or deformable portion (24a, 24b) that is configured to be actuated by applying a force, characterized in that• an electro-optical distance measurement proximity sensor (30) is arranged inside the instrument housing (23), which is arranged and configured to measure a distance information (42) from the proximity sensor (30) inside the instrument housing (23) towards a backside of the physical control element (24) outside the instrument housing (23) through a sensing portion of the front panel (22) behind the physical control element (24) that is optically transparent for the electro-optical distance measurement proximity sensor (30) and• an evaluation electronic (32) that is configured to determine and provide at least one switching state of the control element (24) based on the distance information (43) from the proximity sensor (30).

2. The sealed human machine interface device (20) according to claim 1, characterized in that the evaluation electronic (32) is configured to adjust a function or a provided value of the visual indication element (26) based on the determined state of the control element (24), and / or the evaluation electronic (32) is configured to provide a signal for controlling a machine or a portion of a vehicle based on the determined state of the control element (24).

3. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the electro-optical distance measurement proximity sensor (30) comprises a laser light source (50) transmitting pulses of a directed light beam of a defined wavelength towards the backside of the control element (24), a photo-receiver (51) receiving backscattered portions of the light beam of the defined wavelength from the backside of the control element (24), and a time-of-flight distance measuring and an evaluation electronic (53) configured to determine the distance information (42) according to a time of flight of the pulses from the laser light source (50) through the front panel (22) to the backside of the control element (24) and back to the a photo-receiver (51), in particular with a distance resolution of less than 1mm.

4. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that a measurement direction of the electro-optical distance measurement proximity sensor (30), in particular the direction of the light beam from the laser light source (50), is substantially perpendicular to the front panel (22).

5. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the electro-optical distance measurement proximity sensor (30) is measuring through an optically transparent area of the visual indication element (26), in particular wherein measurement light of the electro- optical distance measurement proximity sensor (30) is passing through the visual display and the front panel (22).

6. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the electro-optical distance measurement proximity sensor (30) is mounted on a printed circuit board (31) inside the instrument housing (23), in particular wherein the printed circuit board (31) is arranged substantially parallel to the front panel (22) and the electro-optical distance measurement proximity sensor (30) is measuring substantially perpendicular to it.

7. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the movable portion of the control element (24) is movable substantially perpendicular to the front panel (22).

8. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the front panel (22) is a single peace, solid, nondeformable, persistent and unperforated throughout the whole front panel (22), also behind the control element (24).

9. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the control element (24) is a button or a switch that is manually movable or deformable in front of the front panel (22) by an operator of the human machine interface device (20),and the electro-optical distance measurement proximity sensor (30) is arranged and configured to measure the movement or deformation of the control element (24) in form of a distance information substantially perpendicular to the front panel (22).

10. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the physical control element (24) is attached to or in front of the front panel (22).

11. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that, the physical control element (24) is in the form of a button with an at least partially deformable dome shape that comprises elastic material, that can be actuated substantially perpendicular to the front panel (22).

12. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that the physical control element (24) is configured as a rubber-dome or Rubber-Key-Pads or as a snap dome or a tactile metal dome or a dome spring, attached outside to the front panel (22).

13. The sealed human machine interface device (20) according to at least one of the previous claims, characterized in that, the physical control element (24) is in the form of a switch providing at least two switching states of a switch-element that is movable substantially perpendicular to the front panel (22) when actuating the switch, in particular wherein the switching states are bistable.

14. Method for determining a manual operation of a physical control element (24) of an operating panel (28) arranged at an outside of an instrument housing (23) of a human machine interface device (20), wherein the manual operation provides a movement or deformation ofthe physical control element (24) perpendicular to a unperforated front panel (22) of the instrument housing (23), with an electro-optical distance measurement through an optical transparent portion of the front panel (22) from an inside of the instrument housing (23) towards a backside of the physical control element (24) by a laser distance measuring sensor (30) that operates perpendicular through the front panel (22) and determines a distance value measurement, and determining an operation state of the physical control element (24) according to the distance value measurement.

15. Method for providing a hermetically sealed housing (23) for an electronic control unit of a human machine interface device (20) that comprises at least one physical control element (24) with a manually movable or deformable portion (24a, 24b) that is configured to be actuated by an operator of the human machine interface device (20) from its frontside, by optically measuring a distance (43) from the inside of the housing (23) through an at least sectional optically transparent, solid and rigid front panel (22) towards a backside of the physical control element (24) perpendicular to the front panel (22), determining a distance value (43) difference by the movement or deformation of the physical control element (24), determining and providing a state of the physical control element (24) according to the distance value (43) difference, and controlling a function of the human machine interface device (20) or of an external device according to the state of the physical control element (24).

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