EP1519453A1 - Portable electronic equipment having at least one I/O terminal adapted for establishing a connection with an electronic unit located within said equipment - Google Patents

Abstract

The instrument has transmission ports interposed on transmission lines (I/OA, I/OB) between input/output terminals (A, B) and corresponding input/output terminals of a processor unit and a memory. The ports have transmission or non-transmission state permitting coupling or uncoupling of respective input/output terminals. A protection unit is interposed on the line between the terminals (A, B) and the ports.

Description

TECHNICAL AREA

The present invention relates generally to an instrument portable electronic device comprising a housing, at least one electronic unit housed at inside the housing, and at least a first input terminal and / or accessible output from the outside of the housing and comprising an electrically connecting element driver which is mounted mobile relative to the housing, this input terminal and / or output being adapted to be electrically connected to an input terminal and / or output of the electronic unit via a transmission line and to enable the transmission of electrical signals on the transmission line through the connecting element, the connecting element being able to occupy a first or second position in which the input and / or output terminal is respectively decoupled or coupled to the input and / or output terminal of the electronic unit,

TECHNOLOGICAL BACKGROUND

Electronic instruments that meet the general definition mentioned above are already known, including JP 11-126155 A, JP 2001-175610 or EP 1 134 630 A1.

JP 11-126115 A and JP 2001-175610 describe solutions similar to providing the portable electronic instrument with a set of terminals input / output placed for example laterally on the housing of the instrument. Each input / output terminal comprises a linkage member movably mounted relative to the housing of the instrument. Each link element is adapted to occupy a first position (ie a rest position not depressed) where the link is decoupled mechanically and electrically from the transmission line corresponding inside the housing and therefore the electronic unit. Each element connection may occupy a second position (ie a depressed position) where a electrical connection is established between the connecting element and the transmission line correspondingly allowing communication with the electronic unit. A specific adapter is used to bring the various link elements into their second position depressed. In addition to the above-mentioned input / output terminals, other similar terminals ensure the charging of an energy accumulator electrical housed in the electronic instrument.

EP 1 134 630 A1 describes another similar solution where a at least one push is used to transmit and / or receive data from the electronic instrument. In this case, the link element of the input / output terminal is formed by the push rod. The interest of this last previous solution resides in the use of one or more control members (typically of the type push-button) for electrically connecting the electronic instrument to a unit external, for example a personal computer. In this way, no contact element specific is necessary to establish an electrical connection between the the external unit, this electrical connection being established as soon as the the control elements configured to present the dual function mentioned above are brought into the depressed position.

A common advantage of the three solutions mentioned above lies in the fact that the connecting element ensures, when not actuated, a mechanical decoupling and electrical input / output terminals and transmission lines corresponding inside the housing of the instrument. This ensures a first level electrical protection of the interface between the electronics housed inside the housing of the instrument and the outside world.

This first level of protection, however, is not sufficient to ensure optimal protection of the interface. So, for example, although the connecting elements provide mechanical and electrical decoupling of the input / output terminals and transmission lines, there is nevertheless a relatively high risk that electrical charges may be introduced on the transmission lines when the actuation of the connecting elements. This risk is all the more important if the electrical potential of the connecting elements is left floating in the state of rest (in position not depressed).

It is also not possible to directly interface a unit electronic transmission lines. Indeed, the electronic unit is typically interfaced to other units, usually by means of a bus that is shared by these components. If the electronic unit were directly interfaced on the transmission lines of the various input / output terminals, it would then exist a significant risk that the accidental or unintentional actuation of the connecting elements causes disturbances on the bus (for example during a read operation or writing data operated in a memory by a processor unit). In the When operating a control device to fulfill the function of the terminal input / output (like the solution described in EP 1 134 630 A1), this problem then becomes critical because the control member can be actuated in any time by the user, especially while the instrument is being manipulated in a electrically conductive medium (eg in water).

To address the problem of electrostatic discharges, it is known to use electrical protection components to establish a path for the discharge of accumulated electrical charges. It is well known protective components, called ESD components ( "e lectro- s tatic d ischarge") or components TVS ( "t ransient v oltage s uppressor"). These components, however, have a major drawback in that they have a very high parasitic capacitance (typically of the order of 1 nF). If such components are placed on the lines in direct connection with the electronic unit, this stray capacitance will be present on these lines and will not only generate a high consumption but also affect the response time of these lines.

SUMMARY OF THE INVENTION

A general object of the present invention is therefore to propose a solution which ensure optimum electrical protection of the interface between the unit electronics and the outside world. Yet another object of the present invention is to propose a solution that makes interfacing without disruption possible between outside world and an electronic unit coupled to other components, for example example via a bus.

The present invention thus relates to a portable electronic instrument whose characteristics are set forth in claim 1.

Advantageous embodiments of the present invention are the subject of the dependent claims.

The proposed solution consists in particular in providing a transmission door interposed on the transmission line between the input / output terminal and the terminal input / output of the electronic unit, this transmission door having a state transmissive or non-transmissive allowing the input / output terminal to be respectively coupled to or decoupled from the input / output terminal of the unit electronic. This transmission door is completed by a protective element against electrostatic discharges interposed on the transmission line between the input / output terminal and the transmission gate.

The portion of the transmission line between the input / output terminal and the transmission gate is typically a high-consumption part. Of made available, the transmission door allows to decouple this portion high-consumption input / output terminals of the electronic unit as long as the input / output terminals are not operated to communicate with the unit electronic. In this way, the ESD protection element does not disturb, in this state, exchanges or communications between the electronic unit and the others system components. The ESD protection element, however, still fulfills its primary function of allowing the establishment of a discharge path between the transmission line (on the portion between the input / output terminal and the transmission gate) and a circuit ground, as long as loads electric accumulate or are introduced in too many numbers on this line. The ESD protection element therefore provides protection for the entrance of the transmission and downstream components, including the electronic unit.

ESD protection element and transmission gate cooperate jointly to ensure optimum electrical protection of the interface between the electronic unit and the outside world. This protection is added to that ensured by the mechanical and electrical decoupling function provided by the input / output terminal and its mobile link element.

According to a preferred embodiment, the electronic unit is coupled to a bus, the transmission line and the input / output terminal of the electronic unit being coupled to a bus line. Preferably, this bus line is brought, in the state unoccupied, at a reference voltage, a first way to pull the bus line to the reference voltage being connected to the bus line, between the door of transmission and the input / output terminal of the electronic unit. A second way to pull the bus line to the reference voltage is also connected to the line of transmission, between the input / output terminal and the transmission gate. In this way, when the transmission gate is made transmissive to allow the establishment of a link between the input / output terminal placed on the housing of the instrument and the input / output terminal of the electronic unit, the second means supplement or supplement the first way in order to compensate for the effects of the capacity parasite of the ESD protection element.

According to another preferred embodiment, the portable electronic instrument includes a user interface, this user interface comprising at least one first control member movably mounted on the housing and operable by a user, this first controller further playing the role of the terminal input / output. According to this embodiment, the control member is advantageously made in the form of a pusher mounted movably in a port of mounted in the housing so as to have a translational stroke according to a actuating axis, this push being operable by pressure to be brought a first position said not depressed to a second so-called depressed position. This pusher comprises an electrically conductive rod, forming the connecting element the input / output terminal, which passes through the mounting hole and has first and second ends opening respectively inside and the outside of the case.

Preferably, the control member actuates a first contact electrically isolated from the connecting element, to produce in response a control signal, and a second electrical contact for establishing, in position depressed, an electrical connection between the connecting element of the input / output terminal and the transmission line. This second electrical contact establishes, when the organ of command occupies the first position, an electrical connection between the element of connection and a specific electrical potential thus avoiding the accumulation of charges on the connecting element.

In general, it is indeed advantageous to provide means for bring the connecting element to a determined electrical potential when this element of link takes the first decoupling position, and to interrupt the connection of the connection element to the electric potential determined when this connecting element occupies the second coupling position and thus enables the transmission of electrical signals on the transmission line. This ensures that electrical charges can not first accumulate on the connecting element.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 montre une vue en plan générale d'un instrument électronique selon l'invention se présentant ici avantageusement sous la forme d'une montre-bracelet comprenant une pluralité d'organes de commande de type bouton-poussoir ;
• la figure 2a est une vue en coupe de l'un des organes de commande de l'instrument de la figure 1, cet organe de commande étant illustré dans sa position non enfoncée ;
• la figure 2b est une vue en coupe similaire à celle de la figure 2a où l'organe de commande est illustré en position enfoncée ;
• la figure 2c est une vue en plan partielle de l'organe de commande de la figure 2a dans sa position non enfoncée ;
• la figure 2d est une vue en plan similaire à celle de la figure 2c où l'organe de commande est illustré en position enfoncée ;
• la figure 3 est une vue de principe de la configuration et du fonctionnement de l'organe de commande des figures 2a à 2d où cet organe de commande remplit, outre sa fonction traditionnelle de commande, une fonction additionnelle permettant la transmission de signaux électriques de et/ou vers l'instrument électronique ; et
• la figure 4 est un schéma bloc illustrant un mode de réalisation préféré de l'interface entre les organes de commande et l'électronique de l'instrument.

Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of various embodiments of the invention given solely by way of nonlimiting examples and illustrated by the appended drawings in which:

• Figure 1 shows a general plan view of an electronic instrument according to the invention is here advantageously in the form of a wristwatch comprising a plurality of push button type control members;
• Figure 2a is a sectional view of one of the control members of the instrument of Figure 1, the control member being shown in its non-recessed position;
• Figure 2b is a sectional view similar to that of Figure 2a where the controller is illustrated in the depressed position;
• Figure 2c is a partial plan view of the control member of Figure 2a in its non-recessed position;
• Figure 2d is a plan view similar to that of Figure 2c where the control member is illustrated in the depressed position;
• FIG. 3 is a basic view of the configuration and operation of the control member of FIGS. 2a to 2d, in which this control member performs, in addition to its traditional control function, an additional function allowing the transmission of electrical signals from and / or to the electronic instrument; and
• Figure 4 is a block diagram illustrating a preferred embodiment of the interface between the control members and the electronics of the instrument.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention proceeds from the general idea of connecting an instrument portable electronics (eg a wristwatch) to an electrical device or external electronics via at least one input / output terminal Accessible from outside the box of the portable electronic instrument (advantageously at least one control element of the user interface is equipped with the portable electronic instrument). By "signal transmission "including" data communication at destination and / or from the portable electronic instrument. The external device can thus be a electronic communication device, for example a personal computer. By "electronic unit", we will understand any unit with which we want interact through the input / output terminals, in particular a processor unit or a memory unit.

The preferred embodiment which will be described later in this description is advantageously based on the use of two control members already present (in this case two pushbuttons) to establish a communication with an electronic unit housed inside the housing of the instrument. It will be understood that the two control members thus configured perform two functions, namely their primary control function for the function selection of the portable electronic instrument (selection of operation or information, update of data or parameters of the portable electronic instrument, e.g. time and / or date, etc.) and function additional input / output terminal for establishing a communication with at least one electronic unit housed inside the housing of the instrument.

It should be mentioned, however, that the invention is not limited to the use of control devices as input / output terminals. For the implementation of the invention, it suffices that each input / output terminal is equipped with a electrically conductive connecting member which is movably mounted relative to the housing so as to occupy at least two distinct positions in which this connecting element is coupled or decoupled from the transmission line corresponding to, for example, the solutions described in the documents JP 11-126115 A and JP 2001-175610 mentioned above). The additional use of the input / output terminal as a control device, as described below, is however, particularly advantageous in that terminals specific are not necessary.

It will be further understood that the transmission of electrical signals can be established when the control device or controls configured for this purpose are brought into their coupling position (in depressed position). The connection of the portable electronic instrument to the external device will be established thanks to a adapter arranged to bring the control members concerned into position pressed. The description of this adapter will not be discussed here because it does not not directly related to the subject of the present invention. In the continuation of the description, it will suffice to understand that this adapter is notably arranged for serve as a communication interface with an external processing unit, such as a personal computer.

The present invention will be described with reference to a timepiece advantageously in the form of a wristwatch. The invention nevertheless applies identically to any portable electronic instrument whether or not he fulfills a watchmaking function.

FIG. 1 shows an overall plan view of a wristwatch, globally denoted by the reference numeral 1, constituting an example of implementation of the invention. It includes a housing 2 delimited in this example by a lower part 3 forming middle and bottom, and an upper part 4 bezel which also carries an ice cream 5. The bezel 4 is adjusted so classic on the middle part 3, a seal being interposed between these elements to ensure the sealing of the housing 2.

The caseband 3 is traversed in this example by five control members push button type respectively denoted by the reference numerals 11, 12, 13, 14 and 15. It goes without saying that this example is given for illustrative purposes only only. The five control members 11 to 15 together form an interface user with whom the carrier can interact to select the various functions of the wristwatch 1.

The control members 11 to 15 are placed here laterally on the middle part 3 in typical places for a wristwatch, namely substantially at 2 o'clock, 3 o'clock, 4 hours, 8 hours and 10 hours respectively. It goes without saying that the control members 11 to 15 could be arranged in other places. One of the control less could be placed on the front of the watch, for example at 6 o'clock.

In what follows, we will focus only on the structure of the organ of 11. In this example, the control members 12, 13, 14 and 15 have a similar configuration. In particular, the two organs of commands 11 and 13 form input / output terminals (designated A and B respectively) for the establishment of a communication with at least one electronics housed inside the housing 2 (such an electronic unit is schematically shown in FIG. 1 and has the reference numeral 72). The control members 14 and 15 are operated to ensure the charging of a accumulator in electrical energy of the portable electronic instrument. The organ of command 12 is only used as a reserve and could be configured as a conventional control member to fulfill only its control role. This control member 12 could also be configured as a crown rod classic for setting the time of the watch.

FIG. 2a shows a partial sectional view of FIG. of the control member 11 along its axis of actuation designated X-X. As already mentioned, the control members 12, 13, 14 and 15 have a similar configuration. The control member 11 is movably mounted in an orifice of assembly 3a formed in the caseband 3 so as to have a translational stroke along the axis of actuation X-X. The control member 11 can be actuated by pressure, as a conventional pusher, to be brought from a first position called not depressed, as illustrated in FIG. 2a, at a second so-called depressed position, illustrated in Figure 2b.

The control member 11 consists mainly of a rod 100, elongated form, made of an electrically conductive material, advantageously made of metal. This rod 100 preferably, but not exclusively, has a shape cylindrical and crosses the middle part 3 from one side to the other. This rod 100 forms the element of link of each input / output terminal. A first end of the rod 100 thus opens into the cavity formed by the middle part 3 while the second end of the rod 100 opens out of the middle part 3 so as to be able to be operated by a user. The sealing is ensured in a conventional manner by one or more O-rings 9 housed in one or more grooves 110 formed on the rod 100.

On its second end, the rod 100 is terminated by a head 120 more large diameter. In this example, the rod 100 and the head 120 of the organ of order are made in one piece. As an alternative, it is perfectly possible to realize these two elements separately and then make them in solidarity with one another or overmoulding a plastic head on the conductor rod 100. To fulfill the desired function of signal transmission electrical appliances, it will be understood that in all cases it is necessary to ensure electrical to the rod 100 from the outside. Overmoulding or mounting a head plastic on the stem should be such that the outer end of the stem can be electrically contacted from the outside.

The middle part 3 is preferably also made of a material electrically conductive, the rod 100 being consequently isolated from this middle part 3 in an insulating sleeve 30. In this preferred example, this caseband 3 is elsewhere carried, in operation, at a determined electrical potential, here the potential mass of the portable instrument as schematized in the figures. The utility of this electrical connection will appear more clearly in the rest of this description.

The insulating sleeve 30 has a generally tubular shape with a shoulder 31 arranged to bear, from outside the middle part 3, on a corresponding shoulder 3b formed in the mounting hole 3a. This sleeve insulation 30 is thus introduced into the mounting hole 3a from the outside and is preferably secured to the middle part 3, for example by driving, screwing or bonding. This sleeve 30 may advantageously be made of plastic material, ceramic material, of anodised aluminum, or any other material in so far as minus the contact surface between the sleeve 30 and the conductive parts surrounding is electrically isolated.

To a certain extent, it might be possible to use a sleeve made of a material with high electrical resistivity (i.e. weakly conductor) so that sufficient current can flow between the rod 100 and the conductive middle 3, thus avoiding the accumulation of electric charges on the rod 100, the resistivity of this sleeve being however chosen to be sufficiently high (for example a few kΩ or MΩ) in order not to disturb the functioning of the internal bus.

An elastic return means 6 formed in this example of a spring helical, is placed between the shoulder 31 of the insulating sleeve 30 and the head 120 of the control organ. When pressing on the control member, this means of reminder 6 is compressed between the shoulder 31 and the head 120 as illustrated in FIG. FIG. 2b, exerting in this way a restoring force tending to bring back the control from its depressed position to its non-depressed position. It will be noted that the shoulder 31 of the insulating sleeve also ensures that the head 120 of the body of control, here conductive, does not come into contact with the caseband 3.

The control member further comprises a retaining element 40 adapted for axially retaining the rod 100 of the control member. For this purpose, the element of retainer 40 is made integral with the rod 100 and is placed on the inner side of the 3 in order to counteract the action of the return means 6 which tends to extract the control member of its housing. The retainer 40 is advantageously configured as a traditional retaining key that is introduced into a groove 140 formed on the rod 100. This retaining element 40 is also made of an electrically conductive material.

In FIG. 2a, it can be seen that, in the non-depressed position, the element of retainer 40 is supported on the middle part 3, at the periphery of the mounting hole 3a. In this way an electrical connection is provided, in an unpressed position, between the rod 100 of the control member and the middle part 3. The rod 100 of the control member is thus brought to the same electrical potential as the middle part 3. In the depressed position, on the other hand, this electrical connection is interrupted because of the axial displacement of the retaining element 40 which accompanies the movement of the rod 100.

In general terms, it will have been understood that the structure of the control is such that, in an unpressed position, the rod 100 of the control is brought to a determined electrical potential, thus making it impossible the accumulation of electrical charges on this same rod. In depressed position, by against, this electrical connection is interrupted, making possible the transmission of electrical signals via the rod 100. For the implementation of the invention, it should be understood that this electrical connection to ground, in position not depressed, is not strictly necessary.

We will now focus more particularly on the configuration of the control device and to the structure of the electrical contacts that allows to ensure, on the one hand, the primary function of the control device and, on the other hand, the additional function of means for transmitting electrical signals.

FIG. 3 shows a basic view of the configuration and operation of the control device envisaged to enable the control member to fulfill, in addition to its traditional control function, an additional function allowing the transmission of electrical signals from and / or to the electronic instrument. The control member is shown diagrammatically in this figure and bears the reference C. This control member C conventionally cooperates with a first electrical contact SW1 to fulfill its control function. A control signal SEL is thus produced in response to the activation of the electrical contact SW1, namely in response to a pressure on the control member C. A second electrical contact SW2, distinct from the first contact SW1 provides the connection with a I / O input / output line connected for example to a processing unit housed inside the portable electronic instrument. This second electrical contact SW2 performs an additional function making it possible to establish an electrical connection between the I / O input / output and the control member C, or more exactly the rod of this control member C. This possibility is schematized in FIG. Figure 3 by the connection of the control member C and the input / output I / O through the electrical contact SW2. This connection is established only when the control member C is brought into the depressed position to close the electrical contact SW2. In the non-depressed position, the electrical contact SW2 connects, as shown schematically, the control member C to a determined electrical potential V _REF represented here as an electric potential forming a mass. It will be understood that the first and second electrical contacts SW1 and SW2 are independent but are nevertheless actuated simultaneously in response to a pressure on the control member C.

The particularity of the proposed control device lies essentially in that, in the non-depressed position, the electrically conductive portion of the control member C, which serves as electrical connection means with the input / output I / O (ie the rod of the control member), is not left in the floating state but is brought to a specific electrical potential, thus avoiding any accumulation electrical charges on this part of the control member.

Referring back to FIGS. 2a and 2b, the description will now be configuration of the aforementioned electrical contacts. In these figures, we can see that the middle part 3 defines an interior cavity in which takes place, so conventional, an electronic module 7 (partially shown in Figure 2a) including a printed circuit board, or PCB, 70 carrying various electrical and electronic components (not shown in these figures) of which one data processing unit (eg microcontroller or microprocessor), storage means (eg EEPROM, FLASH or the like) and other components for the implementation of the functions of the wristwatch 1. watch components (time base, frequency divider, display means analog and / or digital, etc.) are in particular classically provided for in this example to fulfill various horological functions including including the display of time. Reference 75 indicates an optional spacer element disposed on the upper face of the PCB 70 and which supports in particular the display means of the electronic instrument.

In FIGS. 2a and 2b, a source is still partially represented of electrical energy 8 to supply in particular the electronic module 7 above. It can be a traditional battery or an accumulator rechargeable battery (and whose recharge can for example be operated via control members 14, 15, as already mentioned).

In this embodiment, the first electrical contact SW1 of FIG. is conventionally produced in the form of an electrical contact blade 50 comprising a base secured to the electronic module 7 (this base is here maintained between the PCB 70 and the spacer 75) and a flexible extension that cooperates with the end of the rod 100, this end being electrically isolated from the blade of contact 50 by an insulating sheath 150 that can be made of a material similar to that of the insulating sleeve 30. The flexible extension of the contact blade 50 is arranged to be conventionally brought into contact with the other part of the first electrical contact (not shown in Figures 2a and 2b). In this case, it is a metallization 52 formed on the edge of the PCB 70 as illustrated in FIG. partial plan view of Figure 2c. In this figure 2c, the spacer 75 has not been shown in order to discover the entire control device. Figure 2d shows a plan view similar to that of FIG. 2c, control member 11 depressed position, where we can see the flexible extension of the contact blade 50 coming in contact with metallization 52.

The function of the second electrical contact SW2 of FIG. to the retaining element 40 secured to the rod 100 and to a second contact blade 60 disposed tangentially to the rod 100 near its end covered by the insulating sheath 150. This electrical contact blade 60 is it also maintained by its base between the PCB 70 and the spacer 75. In this way, position not depressed (Figures 2a and 2c), the electric contact blade 60 is in contact with the insulating sheath 150 and, in the depressed position (FIGS. 2b and 2d), the blade electrical contact 60 is in contact with the rod 100.

In FIGS. 2a to 2d, it can be seen that the insulating sheath 150 fills two functions, namely the electrical insulation between the rod 100 and the first contact electric (whatever the position of the control device) as well as the insulation between the rod 100 and the electrical contact blade 60 (in the non depressed only). The electrical contact blade 60 could of course be isolated from the rod 100 by means of an insulating sheath separate from the insulating sheath 150.

Note also that the insulating sheath 150 is completed here by a portion of larger diameter. This feature is not necessary but prevents any possible electrical contact between the blades 50 and 60, the portion of larger diameter being interposed between these two blades.

Reference will now be made to the illustration of FIG. 4 to describe a preferred embodiment of the interface between the input / output terminals accessible from outside the housing of the instrument and the electronics of the instrument. As already mentioned above, two control members (namely the control members 11 and 13) advantageously form first and second input / output terminals A and B. Each of these input / output terminals A, B is capable of being coupled to a corresponding input / output terminal of at least one electronic unit (including in particular the units 72, 74) via a transmission line I / O _A , respectively I / O _B. In FIG. 4, two separate electronic units have been illustrated by way of example, namely a processor unit 72 (it may be a microcontroller or a microprocessor) and a memory 74 (e.g. a non-volatile memory of the EEPROM or FLASH type), these components being for example carried by the PCB 70 already mentioned. Each of these electronic units comprises first and second input / output terminals designated respectively by the reference numerals 72 _A , 74 _A and 72 _B , 74 _B. In this preferred example, each of the electronic units 72, 74 is advantageously coupled through its input / output terminals 72 _A , 72 _B and 74 _A , 74 _B to an internal bus comprising two lines designated CLK and DATA. The first and second transmission lines I / O _A and I / O _B are respectively connected to these two lines of the bus.

The lines CLK and DATA of the bus serve respectively for the transmission of a clock (or timing) signal and serial data transmission. he There are various communication protocols using two-line buses as in this case. The description of these protocols will not be discussed here. communication. It suffices to know that the processor unit 72 can for example act as a master and control the operations and the data flow on the bus and that this processor unit 72 can selectively address any other unit coupled to the bus (including the memory 74), for example by sending an addressing frame on the line of DATA data.

It should be noted that interfacing via a bus is not strictly necessary. It would be perfectly possible, for example, to couple the transmission lines I / O _A and I / O _B to the input / output terminals of the processor unit 72 only and to interface the processor unit 72 and the memory 74 with the processor. way of a separate bus. The proposed structure is nevertheless advantageous insofar as one can access one or other of the units 72, 74 (or other units coupled to the bus) via the input / output terminals A, B.

Referring more particularly to each of the transmission lines I / O _A and I / O _B , it can be seen that a transmission gate TG _A , respectively TG _B , is interposed on the transmission line between the input terminal. / output A, resp. B, and the corresponding input / output terminal 72 _A , 74 _A , resp. 72 _B , 74 _B , of each electronic unit 72, 74. Each transmission gate TG _A , TG _B has a transmissive or non-transmissive state enabling the corresponding input / output terminal A, B to be respectively coupled to or decoupled the corresponding input / output terminal of each electronic unit 72, 74. The transmission gates are well known components. For example, reference may be made to the specification of the NC7SZ66 component marketed by Fairchild Semiconductor for a detailed description of such a component.

In addition to the transmission gates TG _A , TG _B mentioned above, a protection element against electrostatic discharges TVS _A , TVS _B is also interposed on each of the I / O _A , I / O _B transmission lines between the input terminal. / output A, B and the transmission gate TG _A , TG _B. In Figure 4, these protection elements TVS _A , TVS _B are represented as a double diode head to tail. It is essentially a passive component, also well known, allowing the establishment of a discharge path when a voltage across the component exceeds a threshold (for example ten Volts). In the case in point, each TVS protection element _A , TVS _B is connected between the transmission line I / O _A , resp. I / O _B , and a mass potential. As mentioned in the preamble, this kind of protection element typically has a parasitic capacitance of high value (of the order of 1 nF).

The portion of the transmission line I / O _A , I / O _B located between the input / output terminal A, B and the transmission gate TG _A , TG _B typically constitutes a high power consumption part. Because of its arrangement, the transmission gate TG _A , TG _B thus makes it possible to decouple this high-power portion from the input / output terminals of each electronic unit 72, 74 as long as the input / output terminals A, B are not used to communicate with the electronics of the instrument. In this way, the protection element TVS _A , TVS _B does not disturb, in this state, exchanges or communications between the electronic units coupled to the internal bus. The TVS _A protective element, TVS _B however still fulfills its primary function is to enable the establishment of a discharge path between the transmission line I _/ O, I / O _B (on the portion between the input / output terminal A, B and the transmission gate TG _A , TG _B ) and the circuit ground, as soon as electric charges accumulate or are introduced in too many numbers on this line. The TVS protection element _A , TVS _B therefore provides protection for the input of the associated transmission gate TG _A , TG _B and downstream components, including the processor unit 72 and the memory 74.

It will therefore be understood that the protection element TVS _A , resp. TVS _B , and transmission gate TG _A , resp. TG _B , cooperate together to provide optimum electrical protection of the interface between the electronics of the instrument and the outside world. This protection is added to that provided by the mechanical and electrical decoupling function provided by the input / output terminal A, B and its mobile link element, namely the control member 11, resp. 13, in this example.

As illustrated in FIG. 4, the transmissive or non-transmissive state of each transmission gate TG _A , TG _B is selected by means of a control signal OE _A , resp. OE _B , applied to an entrance to the door. This control signal OE _A , OE _B is advantageously produced by the processor unit 72 itself. The transmissive state of each door can be activated by the processor unit 72 when the conditions conducive to interfacing with the outside world are present. In particular, the transmissive state of the transmission gates TG _A , TG _B will only be activated when the input / output terminals must actually be used to communicate with the electronics of the instrument. This is the case when the electronic instrument is placed on its adapter and the connecting elements of the input / output terminals are brought into their coupling position. In the example illustrated, however, this should not be the case during a conventional actuation of the control members, for example when selecting functions of the portable electronic instrument.

The activation of transmission gates TG _A , TG _B can be carried out in various ways. In FIG. 4, it can be seen that the processor unit 72 also receives five activation signals SEL ₁ to SEL ₅ originating respectively from the control members 11 to 15 forming the user interface of the instrument. In FIG. 4, the electrical contacts of the control elements 11 and 13 can be seen schematically for the production of the activation signals SEL ₁ and SEL ₃ . Activation of transmission doors TG _A , TG _B could thus be operated following the simultaneous and / or prolonged activation of the five control members 11 to 15 (a situation that would appear essentially when the instrument is placed on its adapter). Alternatively, a function of activating a communication mode could be predefined in the range of functions of the electronic instrument and this function could be called and selected by means of the user interface of the instrument.

As soon as the transmission gates TG _A , TG _B are activated, it will be understood that the high consumption part of the transmission lines I / O _A and I / O _B (we can also speak of an extension of the bus) will be connected. to the internal bus of the electronic instrument. This situation will only appear when the instrument is in communication mode. However, at this moment, the instrument is placed on its adapter, so the problem of consumption is much less acute. Indeed, the power supply of the electronic instrument can for example be ensured by means of an external supply or charging device arranged in the adapter and connected to the instrument by means of other terminals, by example through the control members 14 and 15.

The parasitic capacitance of each TVS _A , TVS _B protection element may nevertheless still be a problem. Indeed, this parasitic capacitance influences not only the consumption but also the response time of the lines in which the information travels. In the case in point, each line CLK, DATA of the internal bus is brought, in the unoccupied state, to a reference voltage, here a high voltage V _CC , via a device called "pull -up ". This is a resistive element R _P1 , resp. R _P2 , (or pull-up resistor) connected between the bus line CLK, resp. DATA, and the high voltage V _DC . The value of this resistance is chosen according to consumption criteria, bus response time and ability of the interfaced components to "drive" this bus, this value must be high to reduce the consumption on the bus, while being sufficiently low, compared to the capacity present on the bus, to minimize the response time.

When activating transmission gates TG _A , TG _B , the parasitic capacitance of each TVS protection element _A , TVS _B is found on the bus line. This parasitic capacitance is therefore added to the capacity already present on the internal bus and would have the consequence, at equal resistance, of an increase in the response time of the bus. This is why an additional pull-up device is placed on each of the I / O transmission lines _A , I / O _B , between the input / output terminals A, B and the transmission gates TG _A , TG _B . Like the elements R _P1 , R _P2 , it is again, in this example, resistive elements R _PA , R _PB connected, this time, between the high-consumption portions of the transmission lines I / O _A , I / O _B and the high voltage V _CC . These additional resistive elements thus make it possible to compensate for the increase in the capacity present on the bus lines during the activation of the transmission gates TG _A , TG _B. It will be understood that the resistive elements R _P1 , R _P2 , R _PA , R _PB could be replaced by other functionally similar devices such as, for example, current sources.

It will be understood that various modifications and / or improvements evident for those skilled in the art can be made to the embodiments described in the present description without departing from the scope of the invention defined by the claims attached. In particular, the present invention is not limited solely to a use in a wristwatch but applies to any other application in a portable electronic instrument.

On the other hand, the use of control devices as terminals input / output, although preferable and advantageous, is not necessary. Other decoupling device comprising an electrically conductive connecting element mounted mobile relative to the housing of the portable electronic instrument and allowing to electrically access the electronics housed inside this housing can be used (for example, previous solutions described in the documents JP 11-126115 A and JP 2001-175610).

The described structure of the control member can also be subjected to numerous modifications without affecting the functions sought for the implementation of the claimed invention. The middle part 3 of the instrument could alternatively be made of a non-conductive material in which case the sleeve 30 is no longer necessary. In this case, it will be preferable to have the rod 100, a conductive reference element brought to the electrical potential determined and to provide that the rod 100 is brought into contact with this element of reference in the not depressed position.

Instead of pushbuttons, we can use any other type of control device in that it has two distinct positions enabling respectively the coupling or the decoupling of the terminals input / output. One can for example think of a stem-crown presenting at least two distinct axial positions. The displacement of the connecting element could elsewhere follow a displacement other than in translation. For example, we can think of a control member where the movable member would be rotated.

We will finally understand that the nature of the electronic unit with which we desire to establish a link through the input / output terminals may be variable. he may be a processor unit as described, a memory unit only, or of a unit whose operating characteristics one wishes to adjust (for example a frequency divider circuit, a sensor, etc.).

Claims (10)

Portable electronic instrument (1) comprising a housing (2), at least one electronic unit (72, 74) housed inside said housing (2), and at least a first input terminal and / or output terminal (A; B) accessible from outside said housing (2) and comprising an electrically conductive connecting element (100) which is mounted to move relative to said housing (2),
said input and / or output terminal (A; B) being adapted to be electrically connected to an input and / or output terminal (72 _A , 74 _A , 72 _B , 74 _B ) of said electronic unit (72, 74) through a transmission line (I / O _A ; I / O _B ) and to allow transmission of electrical signals on said transmission line (I / O _A ; I / O _B ) through said connecting element (100),
said link member (100) being able to occupy a first or second position in which said input and / or output terminal (A; B) is respectively decoupled or coupled to said input and / or output terminal (72 _A , 74); _A , 72 _B , 74 _B ) of the electronic unit,
characterized in that said portable electronic instrument further comprises: a transmission gate (TG _A , TG _B ) interposed on said transmission line (I / O _A ; I / O _B ) between said input and / or output terminal (A; B) and said input terminal and or output (72 _A , 74 _A , 72 _B , 74 _B ) of the electronic unit (72, 74), this transmission gate (TG _A , TG _B ) having a transmissive or non-transmissive state enabling said terminal to the input and / or output (A; B) of being respectively coupled to or decoupled from said input and / or output terminal (72 _A , 74 _A , 72 _B , 74 _B ) of the electronic unit (72, 74); and a protection element (TVS _A ; TVS _B ) against electrostatic discharges interposed on said transmission line (I / O _A ; I / O _B ) between said input terminal and / or output terminal (A; B) and said gate of transmission (TG _A , TG _B ). Portable electronic instrument according to claim 1, characterized in that it further comprises means (3, 30, 40) for bringing said connecting element (100) to a determined electrical potential when said connecting element (100) occupies said first position, and to interrupt the connection of said link member (100) to said determined electric potential when said link member (100) occupies said second position and thereby allow transmission of said electrical signals on said transmission line (I / O _A I / O _B ). Portable electronic instrument according to claim 1 or 2, characterized in that the transmissive or non-transmissive state of said transmission gate (TG _A ; TG _B ) is controlled by a processor unit (72). Portable electronic instrument according to any one of claims 1 to 3, characterized in that it further comprises a user interface (11 to 15) for selecting functions of said portable electronic instrument and in that the transmissive state or not transmissive of said transmission gate (TG _A ; TG _B ) is selected via said user interface (11 to 15). Portable electronic instrument according to any one of the preceding claims, characterized in that it comprises a user interface (11 to 15) for selecting functions of said portable electronic instrument, this user interface comprising at least a first control member (11). ) mounted mobile on said housing (2) and can be actuated by a user,
said first controller (11) further playing the role of said first input terminal and / or output terminal (A). Portable electronic instrument according to claim 5, characterized in that said control member (11) is a pusher movably mounted in a mounting hole (3a) formed in said housing (2) so as to have a translation travel along an axis actuator (XX), this pusher being operable by pressure to be brought from a first position said not depressed to a second so-called depressed position,
said pusher comprising a rod (100) electrically conductive, forming said connecting element, which passes through said mounting hole (3a) and which has first and second ends opening respectively inside and outside said housing (2) . Portable electronic instrument according to claim 5 or 6, characterized in that said control member (11) operates: a first electrical contact (SW1) electrically isolated from said link member (100) for responsively producing a control signal (SEL); and a second electrical contact (SW2) for establishing, in the depressed position, an electrical connection between said connecting element (100) and said transmission line (I / O _A ; I / O _B ), said second electrical contact (SW2) establishing, in said first position, an electrical connection between said connecting element (100) and a determined electrical potential (Vref) thereby avoiding the accumulation of electrical charges on said connecting element (100). Portable electronic instrument according to one of the preceding claims, characterized in that said electronic unit (72, 74) is coupled to a bus, and that said transmission line (I / O _A ; I / O _B ) and said input terminal and / or outlet (72 _a, 74 _a; 72 _B, 74 _B) of the electronic unit (72, 74) are coupled to a line (CLK; DATA) of said bus. Portable electronic instrument according to claim 8, characterized in that said line (CLK; DATA) of the bus is brought, in the unoccupied state, to a reference voltage (V _CC ), a first means (R _P1 ; R _P2 ) to pull said line (CLK; DATA) from the bus to said reference voltage (V _CC ) being connected to the bus line, between said transmission gate (TG _A ; TG _B ) and said input terminal and / or output (72 _A , 74 _A , 72 _B , 74 _B ) of the electronic unit (72, 74),
second means (R _PA ; R _PB ) for pulling said line (CLK; DATA) from the bus to said reference voltage (V _CC ) being connected to the transmission line (I / O _A ; I / O _B ) between said input and / or output terminal (A; B) and said transmission gate (TG _A ; TG _B ). Portable electronic instrument according to any one of the preceding claims, characterized in that it comprises, in addition to the first input terminal and / or output terminal (A), a second input and / or output terminal (B) capable of to be coupled to a second input and / or output terminal (72 _B , 74 _B ) of the electronic unit (72, 74) via a second transmission line (I / O _B ), the transmission lines (I / O _A , I / O _B ) of the first and second input and / or output terminals (A, B) respectively transmitting a clock signal (CLK) and a signal of data (DATA).

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