DE3511601A1 - Signal-processing device - Google Patents

Abstract

A signal-processing device which is accommodated in a closed hand-held housing, in which a surface, facing the operator, with display elements for analog and/or digital character representations, operating elements and signal connections are provided on the outside of the housing, and the surface facing the operator - located at the top in the position of use - is constructed as a homogeneous, transparent and essentially unperforated solid plate consisting of an insulating material, which exhibits at its edge regions sealing faces for connection to side walls or mouldings which form leakage paths, and a membrane-shaped layer exhibiting pressure- or contact-sensitive zones as first operating elements which, in the form of a keyboard, creates electrical contact or capacitive interaction with associated conductors located in the layer in the case of surface pressure or contact, the membrane-shaped layer exhibiting at least one recess or transparent zone which allows a view of a display area and/or mechanically moving identification elements which, in particular, are connected to moving mechanical second operating elements.

Description

description

The invention relates to a signal processing device in the preamble of claim 1 specified Art.

Such signal processing devices, as previously in various Form - but preferably as so-called multiple measuring instruments with a digital numeric display - have the disadvantage that their housing a large number of items, especially with regard to the actuators which, however, usually have to be manufactured and assembled as separate parts, such as push button elements.

It is also not possible to adapt to different use cases Realize without costly changes.

After all, electrical safety is impaired wherever where there are openings for movable key elements or where in use from closed keyboards, no measures are taken to prevent the intrusion Conductor areas leading to higher voltages by means of metallic tips and the like impede.

Because of the electrical safety regulations to be observed therefore often additional measures are required which increase the size or restrict the area of application of the device.

The invention specified in claim 1 is based on the object to design a housing for such a signal processing device so that it with compact dimensions easy usability guaranteed and also offers universal applicability.

The electrical safety of the operator should be versatile Applicability of the device - as far as foreseeable - must be adapted.

The invention is based on the knowledge that the front surface of the device forms the interface of the device to the operator and thus an interactive communication function enables. In the case of a handheld device, this naturally only stands for a relatively small space available, which is used as efficiently as possible must be in order to also meet ergonomic usability.

For multiple measuring instruments to be held in the hand there is already one Flat rectangular design common, which should be retained as far as possible, when it comes to combining a number of different functions into a single one To integrate the device or to provide for its integration.

The housing can be adapted to the most varied by simple adjustments Measurement requirements and a correspondingly modified internal structure of the device can be adapted, without, for example, changes in the injection mold of the plastic housing necessary are. In the course of further development and with devices for special measuring tasks by simply exchanging components and programs as well as designing the the operator-facing surface can be adjusted at any time without the mechanical structure of the device must be changed.

Characterized in that the front surface located in the position of use above a forms a homogeneous solid plate with an essentially impervious structure the operator is electrically secured against the interior of the device.

On the one hand, the front surface thus forms the interactive communication surface between operator and device - is therefore for all information visually the operator are presented - transparent and local for instructions to be entered by the operator sensitive to pressure or touch.

On the other hand, it represents a potential separation between the control surfaces and the interior of the housing containing the electrical circuit boards also for voltages in the kV range occurring in the context of measurement technology.

This security is to be guaranteed even if the surface damaged by sharp tools if handled improperly, as is the case with Penetrating the outer layers with a metallic object poses no risk may arise for the user. However, the operator is in any case safe, because all outside the massive - not for small hand tools penetrable - plate arranged as well as through housing recesses (and feedthroughs) from the outside on a substantially straight path electrical conductor separated from the other circuit parts via high-resistance protective resistors which are located inside the housing. In this way it is possible to use the Control surfaces hermetically sealed and essentially without moving actuating elements to be carried out, which significantly reduces the size of the device. comes. Despite this reduction in size, the concept according to the invention allows the Fulfill security requirements in an excellent way.

By applying the pressure-sensitive zones to the outside of the Transparent surface - preferably in the form of a membrane keyboard - can thus be operated Carry out from the outside, without the security encapsulation for each individual key must be interrupted, as is the case with known concepts. The coupling to the inside takes place laterally through a ribbon cable, whereby the "safety screen" is not weakened if - according to a preferred embodiment - the conductive Membrane keyboard containing areas in the side connection a group of parallel Has ladders, which are flexible through a thin recess in the interior of the housing are performed and there hit a circuit board in an area whose conductor tracks from the remaining conductors of the electrical circuit through the protective resistors and corresponding safety creepage distances are separated. At the edge of the The front surfaces are connected to the side surfaces of the housing by a corresponding one Meander-shaped design of the contact surfaces the necessary creepage conditions adhered to, including the required isolating clearances to the outer housing parts - Precisely because of the otherwise compact design - adhered to in a favorable manner can be.

The membrane keyboard, which is preferably in a correspondingly limited Recess of the front panel is embedded flush, can be in particular in shape one self-adhesive insert the slide without difficulty and remains securely adhered even with the handling necessary in operation.

in combination with the transparent front surface enables all others "Interface" functions towards the operator.

Fixed instructions can be easily put on the keyboard membrane and have a background for a high-contrast representation. The transparency of the cover plate also allows areas that are in the keyboard membrane, which also forms the rest of the cover to non-visible areas of the device, specifically to those parts where operator-relevant displays are arranged below the front or cover plate. This includes an LCD display area, which is connected downstream of the output unit of the device and provides the operator with the information supplies what he expects from the respective (special) device. Thereof in the case of an alphanumeric display, character and text representations as well as graphical representations Includes representations in a variety of forms.

In a further preferred embodiment of the device is a pressure sensitive transparent membrane keypad with keyboard functions provided above the LCD display area, so that the individual key areas are software-controlled by means of the LCD pasting surface Corresponding symbols can be assigned to different functions.

A semitransmissive LCD display is preferably located in front of a thermoluminescent film as lighting, so that even in a darkened environment an unrestricted Use of the device is enabled.

By using a pressure-sensitive membrane keyboard, in printed Single-film multilayer technology results in a number of advantages: It takes a lot takes up little space, is almost bounce-free and is due to a different printing of the Keyboard very flexible. As the symbols on the keys and the digits in the scale and other labeling elements, such as company name, model name A single screen print can be applied in the future in the device just change components or just change the software and use a different one Printing on the membrane keyboard is a completely different device according to color, name and operation from it without changing the mechanical details inside the device would have to be. This is particularly upward compatibility and variability of the device are taken into account.

If also inside the device - preferably via the side-mounted Actuators - changeable mechanically influenced displays made visible you only need a corresponding window in the top of the device covering film to be left free, so that an existing below the recess, highlighted marking becomes visible and thus advantageous in such an Further development of the switch position of laterally attached mechanical function slide switches can display without the operator's head having to be tilted to the Turn your gaze to the side surfaces of the device.

If the input or output connections of the device are also connected to one of the Side surfaces - preferably on the front surfaces - are arranged, this is how the signal feed or the power supply and the output to additional takes place Share evaluation and display devices (such as printers) with devices, the optimal cable routing in the operating position - namely parallel to the base - allow. In the case of most known multiple measuring devices, however, the measuring cables are used led away upwards and thus impede the operator's ability to access the front surface to see or to operate the operating elements available there.

The design of the front surface according to the invention therefore makes it possible on the one hand, to exchange all necessary information between the operator and the device, as far as this exchange takes place visually or mechanically "directed", like those mentioned optical information that is both fixed and movable to the operator perform.

The same applies to the entries made by the operator on the device be fed mechanically, at the same time the necessary separation of the operator from the inside of the device with regard to the live parts at any time without further notice additional measures are guaranteed.

Undirected information, such as acoustic signals, can be included make it perceptible even without opening the device. Such attitudes, which only rarely have to be changed during operation (input selector switch, operating functions) are operated via function switches on the side, which - as they are a complex mechanical Require switching intervention in several functional parts of the device - at this point are optimally arranged.

The measures according to the invention enable the front panel design a use - according to the required universal use - even in the dark or under special lighting conditions of the workplace. If namely - accordingly Another preferred embodiment of the invention - light into the side from the front panel made of transparent material is initiated, this takes over the function of a light guide and illuminates the various optically presented Floodlit areas. This includes, on the one hand, the (passive) LCD display used can also be read at night or under poor lighting conditions. Corresponding also applies to the lighting of movable markings in the device mechanical adjustment elements.

Fixed labels connected to the membrane keyboard on the other hand, transparent (possibly colored), so that this can be done in the dark appear transparently illuminated by the floodlights from below, the adjacent Areas are kept opaque for reasons of contrast.

The same applies to thermo- or barometric scales, which are used for clarification the settings to be read from mechanical elements are provided. The floodlight-like Setting elements is also advantageously marked in such a way that keypads are surrounded by an illuminated surrounding field, so that the actuation surface appears highlighted.

The concept according to the invention can also be combined in a favorable manner with displays that are pressure sensitive Zones in the area of the Display panel are arranged so that by changing representations on the Have the display assign different functions to the zones concerned. Even this variant ensures the necessary contact safety and separation from electrical ones Functions in that the pressure-sensitive areas on the surface of the transparent plate, while the display is from below.

The inventive concept also ensures that even the necessary contact safety when using tools improperly maintain leads. Even if with a screwdriver or another sharp object should be acted on the front surface, so penetrates with the usual forces to be expected, the tip or cutting edge of this tool the front panel does not, so that there is a conductive connection between devices inside and operator does not come.

According to the other underlying devices according to the invention Construction principles form the front surface during assembly or service of the device, the base plate, with all function boards and parts on the massive front panel by means of appropriate guides ready for use "stacked" can be, with only a tub-shaped or U-shaped residual housing removed remains so that all device functions are maintained during the test. All test points of the device are easily accessible and can all switching functions are carried out. The device is located themselves rotated in relation to its position of use, i.e.

Lying on the front surface, as during assembly and repair work not the operating and display functions, but the work inside the device and access to measurement points has priority. The displays on the front of the device can be followed through a double mirror or key operations can be carried out, if the corresponding service or assembly frame has a space between the keypad and document allows.

The production of special versions of the device with adaptation to certain environmental conditions are readily possible because of the inventive A hermetically sealed encapsulation is already provided in the conception. The outside surface of the device only needs to be modified so far that it the respective requirements for robustness of the surfaces and operating elements Takes into account.

The design options of the front panel taking advantage of a transparent insulating material can also be used in a wide variety of creative ways Versions room, whereby frames etc. are preferred for ergonomic separation or Highlighting certain functional areas can be provided. As the operating structure of the device is determined solely by the attached keyboard membrane, can vary Requirements are taken into account, with the size and distribution of the actuators all operating requirements can be met.

According to the task defined above, the front panel should the Include keyboard and display window.

In a known manner, a transparent window is made in the front panel inserted and the keyboard through rectangular recesses in the front panel educated.

This has the disadvantage that the front of the device consists of different Parts consists of: the actual housing front panel, the separate window and the corresponding Keys, similar to how it is solved for a pocket calculator. That in turn implies the Measuring device that all these elements at their edges by appropriate creepage distances marked so as not to endanger the operator.

According to an advantageous development of the invention, the front panel of the device as a whole molded from a highly transparent plastic and forms thus the elements window, dial window, keyboard mounting surface and housing part in one forms.

Based on the consideration that today in electronics largely Membrane keyboards are used that can be glued onto the front panel designed so that the rectangular display window from the otherwise flat Front panel protrudes by a few millimeters and that the remaining area of the plastic part Front panel is lowered by parts of a millimeter.

A membrane keyboard is then preferably inserted into this flat depression glued in, which in turn is opaque, so that only the main display window and the Scale windows that are located next to this display window can, are glass-like transparent.

As will be shown later, the electrical connection of the Keyboard done so that creepage conditions within the framework of safety by an advantageous formation of contact with the electrical inner part of the device is observed will.

The above basic consideration led to another benefit: In general, the designer endeavors to create the front panel of a device on which For example, there is a display window and control elements, by means of a frame of the window, through appropriate printing or decorative strips, a representative To give appearance.

By designing the front part as a transparent plastic part it was possible to achieve that this goal is also taken into account.

Since the other housing parts are designed to be opaque and because the Front panel is designed as a plastic part so that it is the viewer as it were appears exclusively as a millimeter-high tray on which the membrane keyboard is located located, could be achieved that on the edges of the faceplate where the transparent Plastic next to the membrane keyboard can be seen again, a trim-shaped one Frame around the keyboard is provided, which consists of several narrow, parallel, polygonal Stripe-wide surfaces set against each other was formed.

This facet-shaped frame made of fully transparent plastic in highly polished surface finish, similar to a decorative strip, leads to advantageous, Edges marked by light effects.

In addition to these safety and design aspects, the front panel important assembly-related aspects are also met.

Next to the window are two highly polished, transparent surfaces formed by the later the scale display for different areas to be set can be done.

Universal measuring devices of the future will have to be able to measure physical It is also possible to represent quantities quantitatively, for example in the form of numbers have a signal course or signal evaluation also in curve form or in In the form of diagrams. The graphic display, with the possibility of To represent texts, numbers and symbols as well as their ability to also display other forms of representation, like barometric displays or representation in Cartesian or polar or other Taking coordinates is an important piece of information. For small devices Structures that also require low energy consumption, LCD displays with a matrix-like form of representation are particularly suitable. All other two-dimensional; graphic displays require far more energy.

Advantageous further developments of the invention are set out in the subclaims marked or are referred to below together with the description the preferred embodiment of the invention shown in more detail with reference to the figures. It show: Figure la the embodiment in the assembled state and figures lb to d the embodiment according to Figure la in an exploded view, FIG. 2 shows a plan view of the device, FIG. 3 shows a longitudinal section indicated with FIG (A-A) by the exemplary embodiment according to FIG. 1 a and FIG. 4 one in FIG. 2 specified perspective cross-section (B-B) through the device.

The description of the structural design is given at the same time Reference to the various figures showing the components in different Show views - as exploded views or assembled. The description follows in the order of the later assembly, these - as detailed below will be - but in the inverted position of the device with the keyboard facing down based on this.

In the illustrated preferred embodiment is a membrane keyboard 1 provided, which consists of several insulating and conductor layers, with individual Areas of the internal matrix-shaped conductor arrangements by pressing on the corresponding Surface areas with each other in Come into contact and thus push buttons a keypad. The membrane keyboard still points to the front Labels that are to be triggered via the respective contact areas of the keypad Denote functions. There are additional markings on the front panel 2 attached, which denote the functional positions of other switching elements, which can be attached to the side walls of the housing through further recesses the positions of the relevant elements can be read from above, if these Parts carry movable display elements in the form of dial indicators or the like. The markings frame a recess for a display. All for the Operation and reading of optically recorded information are thus at the Top of the device - facing the operator - presented. A tab 3 carries all connections for the membrane keyboard in the form of parallel conductor tracks.

In the illustrated embodiment, one is the membrane keyboard load-bearing front panel 4 is formed entirely from a highly transparent plastic and thus comprises in one piece the following elements: a window 14 to look through the display, another window as a scale window 18 to see through the movable ones Display elements of the switching elements, so that a surface 16 for receiving the membrane keyboard 1. In addition to these functions, the main task of the front panel 3 is in closing the housing at the top.

This ensures that complex assembly processes and the separate Insertion of transparent windows as well of key parts not applicable - as will be shown in detail below. Also arise no harmful creepage distances.

The front panel 4 was used for the advantageous use of adhesive Membrane keyboards designed so that the rectangular display window 14 for the Display protrudes a few millimeters from the otherwise flat front panel and that the remaining area of the plastic part forming the front plate 4 is by parts one millimeter lower.

In this flat depression is the recesses having and in remaining opaque membrane keyboard 1 glued, so that only the display window 7 and scales 4, which are located next to this display window, remain transparent. The electrical connection of the keyboard 1 is preferably carried out in such a way that the Creepage conditions to be observed for the safety of the operator by appropriately designed contacting the internal circuitry of the device can be complied with.

By designing the front part 4 as a transparent plastic part could at the same time also the problem of the lighting of controls and Display can be detached: If light enters from the side, a floodlight-like effect occurs Illumination of the (LCD) display and the operating elements as well as inscriptions, if they (if necessary colored) symbols and characters in a transparent design wear. The lighting effect can be if necessary through an additional device-internal light source can be created. A corresponding thermoluminescent film is not shown in the drawing, but can be according to the sandwich-like Be inserted.

Leave with the one-piece transparent design of the front panel create additional design elements without additional effort. For example by framing the window areas, more prominent by appropriate printing Area in the form of decorative strips, areas of the front surface can be highlighted in such a way that that they are ergonomic - according to their importance in the operation of the device and thus individual operating areas or structures Have the person handling the device grasp it quickly and safely.

Since the other housing parts are made opaque and there the front panel 4 is designed as a plastic part so that it is the viewer appears almost exclusively as a flat tray raised by about a millimeter, on which the membrane keyboard 1 is located, could thus be achieved that on the edges of the front panel where the transparent plastic next to the membrane keyboard remains visible, a trim-shaped frame 17 is formed around the keyboard, made up of several narrow, parallel, polygon-like stripes of width Surfaces is formed. This facet-shaped frame made of fully transparent plastic in a highly polished surface design leads to an advantageous, through a light-flooded Edge delimitation of the entire operating area so that this - If there is an independent light source, also in a darkened environment - Easily perceptible optically as a result of the edges marked by light effects is.

On the side of the front panel facing away from the viewer are on the Outer edge in addition to partially circumferential ribs 19 attached to by reaching over the side walls of the adjoining housing part with respect to the to be attached Creepage distances to meet applicable conditions.

In addition to the aforementioned safety and design aspects, the front panel 4 also fulfills important assembly-related aspects. Next to the Window 14, two highly polished, transparent surfaces 18 are provided through which can later be displayed on the scale for different areas to be set.

There are narrow, rectangular recesses on the two end faces 19 showing the rectangular plates 35 and 40 for holding fasteners 38, 39 and 43 can accommodate.

There are also four through holes on the inside of the front panel 4 15 marked receiving domes for screwing on a display card 30 is provided. There is also a mounting pin - roughly adjacent to the center of the keyboard 10 as a centering and receptacle for the individual circuit boards present in the device 20, 60 and 70.

There are four tenons on the four corners of the inside of the faceplate 8, each of which has an inner hole, attached, which will later be used to accommodate the screw connection of the entire housing. Furthermore, a slot is in the front panel 4 in the lower part 5 provided, through which the ribbon cable-shaped contacts 3 of the keyboard 1 out and can be picked up on the inside via small pins 6, which serve as an assembly aid. The pins 8 have blind bores with a thread, which contain screw openings that are open to the inside of the device.

The top of the device is due to the closed design of the front panel hermetically protected. The front plate 4 is a self-contained insulating Plastic part forms, with any creepage distances always its outer edge area include and thus easily a sufficient contact security according to the relevant regulations, what with an arrangement with separate Button and window inserts would not be feasible.

The membrane keyboard 1 is from the front on the front panel 4 glued and the ribbon cable 3 passed through the slot 5 just mentioned in such a way that that it points into the interior of the device, so that the front panel 4 with the front side is inserted down in a simple manner in a mounting receptacle formed in this way. The ribbon cable 3 is inserted into two small receiving pins 6, with a zebra rubber 11 of two small frame-shaped adjustment elements is received with an adjacent one Controller card 20 is connected. The slot in the massive front panel 4th is arranged so that the substantially straight piercing on the neighboring controller card cannot hit any areas that are dangerous Conduct voltages or currents. The connections leading to contact elements 22 on the circuit board 20 are provided with protective resistors R, which high-resistance Form effective resistances and ensure that all conductors are in the appropriate The outer zone of the plate 20 including the foil conductor 3 and the foil keyboard 1 is protected are. The range of the high-voltage resistant resistors R is creepage distance and track free.

The one-piece front panel 4 thus unites at the same time the following functional parts, which would otherwise have to be carried out separately: a. Housing front part, b. Viewing window without creepage distance for the display 14, c. Scale display window 18, d. Keyboard receptacle, e. Design-oriented framework formation, if necessary as an orientation aid f. light guide for floodlights g. Mounting bracket for the membrane keyboard, h. Cradle for all cards, i. Mounting fixture for the slide switch parts, k. Cradle for front parts 75 and 80, 1st adjustment device for all cards as well as with receiving part of the housing screws 86.

This very advantageous design of the front panel 4 is thus used both the aspects of safety, reliability, the variability, assembly, inspection and testing, and ease of servicing, and thus educates a central structural element of the device.

The first of the circuit boards carrying electronic components, here Called the controller card, is plugged over a pin 10 on the two screw pins screwed tight and fixed by elastic pipe sections 9.

There are two more zebra rubber assemblies on the controller card 20 22 and 23. One is used to accommodate the membrane keyboard contacts 22, the other 23 of the contact with the display card 30, which is fastened by means of two screws 12 is.

Another middle card 60 is together with switch elements 50, 47, 40, 52, 49, 41, 50, 47, 40, 52, 49, 41, 53 and 54 on the through means the underlying front panel mounting device 4 attached in such a way that the creepage strips 19 on the respective longitudinal edges of the front panel at the same time serve as a sliding device for the switches.

At the top is a circuit board 70 carrying the microprocessor - likewise placed over the central pin 10 and fastened by elastic spacer tubes. The end plates 75 and 80 are inserted with the connectors and soldered.

The actual housing is formed by the housing lower part 85. It is shaped as a plastic part in such a way that that it is as a counterpart to the front panel 4 laterally has recesses 89 for receiving the slide switch.

Furthermore, there are recesses 90 for receiving end plates 75 and 80 and housing screws 86 available.

The lower housing part 85 is made of an opaque plastic manufactured and contains formations forming creepage distances on all outer edges in the form of deep U-shaped grooves 91 or in the form of additional surfaces, which - embedded in the housing part - are not accessible from the outside.

The four receiving pins 92 for the housing screws 86 are of this type formed that they in turn enclose the pin 8 of the front plate 4 in a tubular shape, to give them additional support when screwing plastic parts together.

The bearing surfaces for the housing screws 86 are set deeper, On the one hand, to take into account the safety aspect through an additional creepage distance to wear and in addition to the hollow cylinder of the screw feed holes to be able to press in the cylindrical cover parts 88, as measures against unauthorized persons Opening, guarantee purposes and security.

The housing 85 has on its bottom plate at the edge of the side surfaces a number of cylindrical studs 93 which are injected with the ground. These Pins are used to lock the slide switches on these massive cylinders slide along and thus acoustically and mechanically niche when actuated the slide switch report the latching effect.

In an alternative embodiment, these locking elements can also be used in the front panel 4 are provided. In the embodiment shown here For reasons of the spatial arrangement of the other components, they were placed in the lower one Housing part relocated.

Geometrically opposite the pin 10 of the front panel 4 is a plate-shaped receptacle 94 is provided for adjustment purposes.

In polygonal, i.e. twelve-sided, lateral detents on the lower part of the housing 85 is a stand 95 made of transparent material in different angular positions attachable so that a favorable viewing angle according to the lighting conditions can be freely chosen. The stand 95 can be rotated by 180C Can also be used as a cover for the keyboard and protects against unwanted Operating errors. Feet 96 protect the stand from scratching. A nameplate 97 is embedded in the stand and is visible in the cover position.

In the partial representations according to FIG. 4 and the exploded view according to Figure lc, the switch assembly can be seen. It represents an essential Construction element in all electronic devices, but especially in measuring devices, . By inexpensive construction of this assembly, the costs, the design and the confidence the essentials of a device - mostly Determine the extent that cannot be assessed in advance.

In the device type described here in "hand-held" design there are particular difficulties in construction. By the chosen constructive Solution is a large number of constructive difficulties in a small space Taken into account, the measures found mutually in an astonishing way support financially.

Based on the idea that printed circuit boards represent the essential connecting element for electronic components today, were the contact surfaces 62 directly in a geometrically favorable shape on the Printed circuit board 60 brought. A concept known per se has been modified here in such a way that that on the long sides 69 of the cards on the one hand on the top and on the other arranged on the opposite underside as contact surfaces so that a in the direction of the card edges U-shaped bent spring 53 each the contact surfaces Connect on the top with the corresponding mating contact surfaces on the bottom can.

Since the U-shaped bent spring 53 by being pushed onto the edge of the card 69 is bent open by itself, its restoring force generates the necessary contact pressure. The spring 53 made of a conductive spring material can be bent in a U-shape thus the corresponding contact surfaces 62 in each case in a specific position connect the top to the bottom of the card.

Are the individual contact surfaces 62 on the top and bottom the card 60 connected to the other circuit parts so that they each required connection configurations for a translational movement of the Reach contact spring 53 in the direction of the card longitudinal edge 69 in positions, so a position-dependent slide switch can be developed from this basic element.

Are several such springs 53 in a switch bracket 50, 52, 50, 52 housed at certain intervals so that they, guided in parallel, the contact elements Connect 62 on the top and bottom in the same constellation, you can do several with such a switch and its position-dependent movement Contact elements 62 simultaneously opening or closing and connect to them Way to fulfill complex switching functions.

In the switch bracket 50, 52, 50, 52 are each a number of Cuboid-shaped cavities (for example 51) are provided in the contact springs 53 can be inserted. These cavities are designed so that the Spring 53 a sufficient mechanical degree of freedom in the direction of movement perpendicular to the card 60 has to dimensional tolerances, the position of the cards 60 itself and which concern the moving switch bracket 50, no influence on the contact reliability, i.e. can take on the position of the contact springs 53. This ensures that that the position of the springs 53 solely by the geometry of the card 60 and is not determined by the position of the switch bracket 50.

However, the switch bracket 50 is shaped so that when it is moved of the switch bracket in the direction of the longitudinal edge 69 of the card 60, the springs 53 are entrained can be guided in order to reach the other switching positions in parallel can.

In practice, the switch bracket 50 must be perpendicular by a few millimeters can be moved to the card 60 without the contact springs mounted in it 53 lift off the contact surfaces 62. On the other hand, the side edges of the feathers must can be guided step by step through the contact bracket with the least amount of friction. This requires burr-free cut surfaces on the side edges of the springs and highly polished Side surfaces of the switch bracket made of an insulating plastic.

In the present version, this switch bracket is with a additional metal molded part, e.g. a stamped part 47, which in the here the present application case of the shielding.

If the switch bracket 50 and the umbrella part 47 with a screw 54 inserted into the switch button 40 and then with the self-tapping Screw 54 tightened, then forms the switch button 40 together with the screen part 47, the switch bracket 50 and the switch springs installed in the switch bracket 53 the actual switch element.

Can the shielding of the switch contact springs 53 be dispensed with? you can also use the switch buttons and the switch bracket are made from a single cohesive plastic part.

The switch button 40, 41 fulfills several functions at the same time. On the one hand, it is designed so that its switch button - the function of a slide switch accordingly - thanks to the large-scale design, it can also be used as a screen for represents the sliding path slot 89 that is necessarily to be provided in the case of the slide switch.

Because the switch button is accessible from the outside of the device must be, was in the present preferred embodiment with the screen effect also linked to the fulfillment of the creepage distance conditions.

There is a common one on the outside of the switch button Corrugation to provide the necessary frictional connection with the palms of the hands or fingers to create.

The internal mechanical parts of the consisting of a piece of plastic Switch buttons are designed so that they are rail-shaped in the slots the housing can be performed.

At the bottom of the switch button - inside the device pointing - two elements 43 which can be described by spring arms can be seen as Detent spring elements 44 act. The ends of the leaf spring-shaped locking spring 43 are cylindrically designed 44 that they with the cylinder pin 93, the are located in the housing 85, form a detent.

It is also located on the upper side - also in the interior of the housing pointing - a web 42 on the switch button, which is inside the device for receiving of position display elements 45 and 46 is used. These position indicators are used later together with the transparent front part 4 for display within the device scale.

In the application described here for the inventive Switches, four complex switch assemblies are provided, all of which are nonetheless take up little space. These are the two mode switches with the switch buttons 41 and the two measuring range switches with the switch button 40.

It was also possible to achieve that the actual contact springs 53 - regardless of any tolerances in their position exclusively by the Position of the card 60 on which the contact surfaces 62 are located can be determined.

The slide switch and the contact springs 53 moved with it ensure for a certain self-cleaning of the contact elements 62. Your contact pressure is can be determined by the design of the spring. This means that the abrasion is on the contact surfaces to keep within limits.

Since the contact button simultaneously functions as a cover, sliding guide, Latch, connecting element to the switch and carrier element for the position indicator 45 and 46 and with the plastic housing 85 the latching det, relatively complex functions can be fulfilled with little construction effort.

The slide switch of the embodiment described here has first of all an additional constructive feature. A linearly movable one Switching element is generally only shielded with a certain amount of additional effort. Since with a rotary switch the switching movement is carried out exclusively via one axis and this easily through a hole provided in a screen housing is usually a rotary switch in use for a Measuring device - especially if this is, as in the present case, for a very broadband Application is intended - with regard to the shielding effort and shielding security think.

By inserting one with additional sliding contacts 48 provided shield plate 47 over the switch bracket 50 could this difficulty can be met in a surprisingly easier way in terms of construction.

In Figure 4 it can be seen that the housing 85 as a counterpart to the front panel 4 laterally has recesses 83 for the slide switch, and on all outer edges Creep-oriented training in the form of deep U-shaped grooves 91 or has additional surfaces.

The drawing shows the engaged detent between the Pin 44, the detent spring 43 of the switch button 40, 41 and the pointed in the housing Pin 93, as well as the position elements 45, 46 received in a web 42, the the positions of the slide switch 40, 41 through the window 18 in the front panel 4 on the device scale 2.

It is also clearly visible how the switch bracket 50, 52 with a shield 47, 49 is screwed against the switch button 40, 41 is located Contact springs 53 on the longitudinal edge 69 on the top and bottom of the circuit board 60 applied contact surfaces 62 act.

The main function carriers in a device of this type are the electronic ones Components, especially the integrated circuits. You have to be on so-called printed circuit cards are mechanically fastened and carried and also take over these printed circuit boards function the individual electrical components to connect with each other in their organization.

As in this device complex integrated circuits, in subordinate Function so-called passive or active components of conventional design are used are assembled and soldered accordingly a large number of components Your organization must be properly connected is the structure and the breakdown the individual functions on the individual cards are extremely important.

The structural design and fastening of the cards was chosen in such a way that that a high degree of flexibility with a different configuration of this in the future Cards is preserved.

The layered sandwich arrangement of the assembled device appears thus as follows. In the embodiment shown here, there are five main levels distinguishable: 1. The membrane keyboard 1 is located on the outside of the device and is accessible to the operator.

2. The controller card 20, which essentially performs the functions of the Keyboard command sequence interpretation and the control of the display element 29 - here LCD element - makes.

3. The LCD element 29, the optical display surface of the device, consisting of from a matrix LCD 31 and a card 30, the so-called driver modules for the matrix LCD carries.

4. The converter card 60, here also called analog card, which receives the input signals of the measuring device in analog or digital form and to process it and above all the conversion of the recorded signals into from the micro-computer signals to be processed allowed.

5. The micro-computer card 70 that the micro-processors with the each associated memory also includes upgradeable upward compatibility.

These five functional levels are electrically connected to each other in such a way that that these cards are each checked separately for their functions, step by step into the Device can be installed and contacted.

The assembly process and thus the connection techniques are now to be described below of the device: The front panel 4 is used in the following to be described Assembly phase as a carrier plate and is also referred to as such.

First, the membrane keyboard 1 is glued to the front panel 4. Care must be taken that the ribbon cable 3 on the operating side facing away from the keyboard surface protrudes through the slot 5 in the Front panel 4 is guided and so gets to the inside of the device that it is there bent at the two pins 6 can initially be held mechanically.

Then four rubber 0-rings 7 are placed on the four corners of the Front plate located screw cylinder 8 attached. They will later be used for elastically correct absorption when screwing the entire device together.

Furthermore, the is also made of an elastic material tubular spacer buffers 9 placed on the center pin 10 of the front panel 2. It will later serve as an elastic support for the controller card 20. Then it will the zebra rubber 11 on the ribbon cable contacts 3 through the frame-shaped side parts 12 placed in the carrier plate 4 positioned.

Now the controller card 20 with the help of the two Phillips screws 25 through the center pin 10 of the support plate 4 and the hole 24 in the controller map 20 guided, put on and screwed together with this screwing process the controller card 20 is attached and over the zebra rubber 11 with the coordinate contacts the membrane keyboard 1 connected for assembly.

On the other side of the controller card 20 are also located Zebra contacts 23, on which the zebra rubber 27 can then be placed, which later establish contact from the controller card 20 to the display card 30.

The display card 30 itself is over the elastic washers 28 placed with the help of the two screws 33 and screwed, so that now the Zebra rubber 27 is the contact element between the controller card 20 and the LCD display 29 forms.

The contact plug-in elements were already in the controller card 20 when it was fitted 26, these are so-called inline connectors, applied by normal assembly and soldering. These connector elements, now supplied with current and voltage, can be used simultaneously the keyboard 1, the controller card 20 and / or the LCD 29 can be checked.

The plug contacts 26 also make the connection later at the same time to the next card 60 and to the microprocessor card 70.

On the center pin 10 of the support plate 4 is now the elastic Spacer tube 56 and also the insulating, likewise elastic spacer tubes 57 on the still not screwed longitudinal fastening slots 32 of the LCD display 29 attached or placed.

The converter card 60 is also used for the final assembly of the device Supplied fully equipped and tested. The shielding elements are also located on it 64 and 65 and the shielding elements 66 and 67, which shield the analog amplifier channels to serve.

At the same time, the switch elements are delivered to the assembly department. There are on the switch buttons 40 and and on the switch button 41 the switch bracket 50 or

52, which were connected to one another with the aid of the screws 54.

In a further operation, the contact springs 53 are attached to the correct ones Positions plugged into the switch bracket.

These four switch elements are now on the two long edges 69 of the converter card 60 inserted so that the locking spring elements, for example designated by 81, point in the direction of the lower housing part 85.

The one provided in such a way with all screen elements and switch elements Converter card 60 can now also with its dimension reference hole located in the lower part 61 are placed on the pin 10 in the front panel 4.

Care must be taken that the four switch buttons are on the rail-shaped creepage distance edge 19 of the front plate 4 inserted cleanly will.

Appropriate devices must always be taken into account here that connector elements (here 55), which are also already on the analog card 60 are located, correctly soldered in position and direction, so that they in the plug or the plug arrangement, consisting of the socket strips 26, so fit so that no tolerance shifts take place. Allow the plugs however, there is a certain tolerance in the height adjustment of the individual in their insertion direction Cards.

Since the connector can make a certain amount of definition of the cards The converter card 60 is now fastened via the screws 68 via the fastening bores 32 of the display 29 in the carrier plate 4 take place.

An elastic spacer tube 71 is then placed on the mounting pin inserted in the carrier plate 4, that in turn the correct distance to the then to assembling micro-computer card 70 is preserved. This micro-computer card 70 is connected to the analog card 60 via the plug connection elements 72, the essentially the bus structures, the power supply and the connection all other map layers. At this point the device is in its electrical Main functional levels compiled and could be checked for overall functions.

Holes located in the micro-computer card 70 can also the analog card 60 is now checked and adjusted in its final function test will.

The elastic O-ring 74 provides a buffer against the actual Housing 85 reached.

The connector walls 75 and 80 were previously with the necessary connectors and sockets and the associated screwing parts 78, 79, 77, 82, 83, 81 are provided and you can now use the guide and creeping path slots provided for this purpose Carrier plate 4 can be used and with those located on the individual cards Connections are connected by wires.

If the two cards 20 and 30 are on the front panel 4, so the first test for functionality can be carried out via the socket strips 26. An advantageous holding device as an assembly aid is designed in such a way that that for the person assembling the device the display has a double mirror system 31 is visible during the test process, so that the assemblies already assembled can be fully checked for their function.

If you now lead from the outside, for example via a plug part 76, the If voltage is applied, its function and all operating modes can be fully tested Can be simulated using the switches and the keyboard. Nevertheless, the cards are in sandwich construction mounted, accessible from the side and the device can undergo a functional test and visual inspection be subjected.

If this test is passed, it can be done with the help of the screws 86 The housing 85 provided with the glued-on rubber feet 87 is slipped over the device and screwed will.

In this way, the front panel is used for step-by-step assembly, testing and inclusion of all functional parts up to the completely tested device, so that then the actual housing lower part 85 can be put on and screwed.

Finally, the guarantee plugs 88 are pressed in.

The device is installed, checked and ready for use.

With this description, all connection techniques and assembly strategies are explained.

The invention is not limited in its implementation to the above specified preferred embodiment. Rather, it is a number of variations conceivable which of the solution shown are also fundamentally different Make use of the explanations.

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Claims (17)

Signal processing device claims 1. Signal processing device that is housed in a hand-held, closed housing, wherein the following are provided on the outside of the housing: one facing the operator Area with display elements for analog and / or digital character representations, Actuating elements and signal connections e t that the operator facing - in the position of use above - surface as homogeneous, transparent and essentially uninterrupted as well as made of an insulating material existing massive plate is formed, which has: at its edge regions Sealing surfaces for connection to side walls or formations, which creepage distances form a pressure- or touch-sensitive zone as the first actuating elements having film-shaped layer, which is in the form of a keyboard with surface pressure or touching electrical contact or capacitive action when assigned in the layer Generated conductors, the film-shaped layer at least one recess or has a transparent zone, which the view of a display surface and / or mechanically movable identification elements allows, in particular with movable mechanical second actuators are connected. 2. Signal processing device according to claim 1, d a -d u r c h g e k It is noted that the conductors have cables leading into the interior of the device lead, are connected to the first terminals of protective resistors, which the in the case of one to be specified, the operation at any point inside the device Occurring voltages exceed the maximum voltage flowing current to a limit harmless value to the human body, with each other Connections of the resistors directly or indirectly exclusively with circuit areas are connected, which after penetrating the film-shaped layer and at most a recess in the plate on a straight or moderately curved path from the outside of the housing are accessible. 3. Signal processing device according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that the foil-shaped layer is used as a foil keyboard is formed with conductor tracks intersecting in a matrix-like manner. 4. Signal processing device according to claim 3, d a -d u r c h g e k It is noted that the membrane keyboard is glued to the panel and at least one recess for looking through a behind the transparent plate having arranged inside the display elements forming LCD matrix. 5. Signal processing device according to one of claims 1 or 2, d a d u r h e k e nn n nn z e i n g n e t that the plate has a display element for character representations containing LCD display, in front of the on the outer surface a transparent membrane keyboard is provided. 6. Signal processing device according to claim 5, d a -d u r c h g e k It is noted that the membrane keyboard works capacitively. 7. Signal processing device according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that the membrane keypad can be used in two-dimensional Recesses of the plate is embedded. 8. Signal processing device according to one of claims 4 to 7, d a it is indicated that the LCD matrix is semitransmissive and can be penetrated by a light source provided in the interior of the housing. 9. Signal processing device according to claim 9, d a -d u r c h g e k It is noted that the light source is formed by an electroluminescent film will. 10. Signal processing device according to one of the preceding claims, characterized that the membrane keyboard symbols or symbols that are printed adjacent to the actuating and / or display elements Has scales. 11. Signal processing device according to one of the preceding claims, D a d u r c h e k e n n n z e i n e t that the front panel is essentially extends parallel to the circuit boards located in the device. 12. Signal processing device according to claim 11, characterized in that that the circuit boards in the device are sandwiched parallel to the front panel are stacked. 13. Signal processing device according to claim 1, characterized in that that the element that completes the front panel to form a complete housing or U-shaped. 14. Signal processing device according to one of the preceding claims, d u r c h e k e nn n e i n e i n e t that the front panel is the mounting surface for the printed circuit boards. 15. Signal processing device according to one of claims 2 to 14, d a d u r c h e k e n n n z e i c h n e t that for the implementation a band-shaped connection for the glued-on membrane keyboard a narrow passage is provided in the front surface. 16. Signal processing device according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that the edge of the front surface has at least one has partially circumferential raised web on the side facing away from the operator, wherein the web in cooperation with an adjacent, enclosing the web Housing part forms a meandering creepage distance. 17. Signal processing device according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that at least one separate sheet-like housing element adjoins, which at least one connection element for an external supply line and to the adjacent housing parts while generating a meandering creepage distance at the borders to the neighboring housing parts is attachable.