WO2010088958A1

WO2010088958A1 - Electronic array comprising at least two dimensions

Info

Publication number: WO2010088958A1
Application number: PCT/EP2009/051352
Authority: WO
Inventors: Michaël DEMEYERE
Original assignee: Agc Glass Europe
Priority date: 2009-02-06
Filing date: 2009-02-06
Publication date: 2010-08-12
Also published as: EP2394493A1

Abstract

The invention relates to an electronic array comprising a power supply unit (10), (11), a first electronic unit and a second electronic unit in a first dimension, wherein the first electronic unit and the second electronic unit each comprise a management unit, and the first electronic unit and the second electronic unit are arranged in series to each other, further comprising a third electronic unit and a fourth electronic unit in a second dimension, wherein the second dimension is arranged perpendicular to the first dimension, wherein the third electronic unit and the fourth electronic unit each comprise a management unit, and the third electronic unit and the fourth electronic unit are arranged in series to each other. In this way, a simple, cheap and steadily ready-to-operate electronic array adapted for electronic circuit applications is provided.

Description

ELECTRONIC ARRAY COMPRISING AT LEAST TWO DIMENSIONS

FIELD OF THE INVENTION

The invention relates to the field of lighting and electronic arrays, preferably adapted for electronic circuit applications as well as methods of use of lighting.

BACKGROUND OF THE INVENTION

It is generally known for printed circuit boards, PCB for short, that the physical arrangement of the electronic components thereon, in the following also referred to as electronic units, shows little or no influence on the connection mode of the electronic units with respect to one another. This is due to the resistivity of the conductive tracks which is negligible, e.g. metallic copper tracks are used. In conventional electronics on PCB' s, such conductive tracks can have dimensions adequate to support electronic current densities such that the system performance does not suffer. This means that these dimensions can be as long as necessary. A conventional and effective way to proceed is thus to connect all the electronic units in parallel.

However, on a resistive substrate such as glass comprising a high resistance conductive layer, portions of the conductive layer have to be removed to leave conductive tracks with a high resistance. It goes without saying that it becomes necessary to ensure that these conductive tracks are as short and as wide as possible.

A conventional solution to achieve an electronic matrix, in the following also referred to as an electronic array that comprises a plurality of electronic units, is to provide in a column, i.e. in a first dimension of such an electronic array arranged in a current direction, a plurality of electronic units that are connected in series to one another. Columns of electronic components are connected in parallel with each other. The conventional solution is illustrated in Fig. 1. This figure shows a power supply unit 1 and an elec- tronic array 2 comprising a plurality of electronic units. Conductive areas which are isolated from one another and the link between such areas performed by electronic units are illustrated in this figure. The electronic units are shown as small squares in Fig. 1. Areas of no conductive layer are illustrated as vertical and horizontal dark lines. How- ever, in such a conventional solution the electronic units cannot be addressed individually. Furthermore, it would be preferable to supply a control signal to the electronic units.

The electric current flowing through electronic units which are connected in series is bound to be the same for each one of the electronic units. Nevertheless, the conventional solution is particularly disadvantageous if an electronic unit malfunctions or fails, respectively.

In case of a malfunction of an electronic unit, one can further distinguish between two cases which underline the disadvantages of Fig. 1: The first case includes an electronic unit going "open circuit", i.e. showing a large or an infinite resistance, the second case includes an electronic unit being "short circuited", i.e. showing zero resistance. According to the first case, the electric current can no longer pass through the electronic unit and thus through the column of the electronic array and all electronic units comprised by the electronic array in this column stop working. According to the second case, the impedance of the column of electronic components has changed. This impedance is made up of the resistance of the electronic unit and of the conductive layer on the substrate. Even if the electronic units continue to function, they may deteriorate, for instance, because of a higher and maybe a too high electric flows through them.

According to a second conventional solution which is more advantageous compared to that of Fig. 1, the isolating separations between columns on the conductive substrate are removed. This is shown in Fig. 2 in which the dark vertical lines of the electronic array 2 have been removed. In the absence of a malfunction or a failure of an electronic unit, the electronic array behaves identically as in case of Fig. 1. A malfunction of the electronic unit in case of a "short circuit" has the same consequences as in the example of Fig. 1. In addition it may also disrupt the neighbouring electronic unit or units which can receive less electric current. However, in contrast to Fig. 1, malfunction in case of "open circuit" shows less of a problem than in the example of Fig. 1. The electric current cannot pass through the electronic unit that has failed and is deflected in a natural way around it to other components. The electric current passes through the functionally neighbouring electronic units. However, the rest of the affected column continues to operate, which is an improvement compared to the example of Fig. 1.

There still remain two problems in the example of Fig. 2. As in the short-circuit case of Fig. 1, the total impedance of the affected column is changed and the operation of the column is not optimal. In the open-circuit case, the fact that extra electric current is spread over the neighbouring electronic units results in additional electrical stress. Therefore, the neighbouring electronic units are more likely to break-down or to break down more quickly.

An applications of an array as shown in Figs. 1 or 2 comprises a regular electronic array of voltage supplied light emitting diodes, LEDs. Although LEDs are typically current regulated, working on a resistive substrate allows also voltage regulation. In the apparatus of Fig. 1 and in the short-circuit case, the LEDs of the affected column will illumi- nate more strongly than the rest of the electronic array. As the supply voltage is fixed and the total resistance of the column is diminished by the short circuit, the power consumption becomes higher. In the open-circuit case of Fig. 1, the LEDs of the affected column will not illuminate anymore. In the short-circuit case of Fig. 2, the same happens as in the solution of Fig. 1. Moreover, the neighbouring LEDs, i.e. the adjacent columns, will illuminate less because the current will preferably flow through the LED short-circuit. In the open-circuit case of Fig. 2, the LEDs neighbouring the faulty LED will illuminate more, i.e. shows more electric current than the rest of the electronic array comprising a plurality of LEDs.

The human eye is sensitive changes in light emission power and also can be disturbed when patterns are disturbed, e.g. parts of the pattern are missing. Thus, there is a need to provide a better solution of arrays of electronic component, especially those that emit light.

SUMMARY OF THE INVENTION

It is the object of the invention to provide alternative lighting and electronic arrays, preferably adapted for electronic circuit applications as well as alternative methods of use of lighting.

An advantage of embodiments of the present invention is a possibility to obtain a simple, cheap and steadily ready-to-operate electronic array preferably adapted for electronic circuit applications.

The above object is achieved by an electronic array according to independent claim 1. The electronic array comprises a power supply unit, a first electronic unit and a second electronic unit in a first dimension, wherein the first electronic unit and the second electronic unit each have an associated a management unit, and the first electronic unit and the second electronic unit are arranged in series to each other, further comprising a third electronic unit and a fourth electronic unit in a second dimension, wherein the second dimension is arranged at an angle, e.g. perpendicular to the first dimension, wherein the third electronic unit and the fourth electronic unit each have an associated management unit, and the third electronic unit and the fourth electronic unit are arranged in series to each other.

It is an essential idea of the invention that the electronic array comprises at least two dimensions, wherein in each dimension identical or nearly identical electronic units are arranged preferably on a conductive resistive substrate such as glass comprising a conductive layer adapted for conducting electricity. The two dimensions may be defined by Cartesian co-ordinates or polar co-ordinates, for example. The electronic array com- prises a plurality of electronic units wherein each electronic unit comprises a management unit. Most preferably, the connection method used is the connection method de- scribed in connection with Fig. 2.

According to a preferred embodiment of the invention, the angled or perpendicular arrangement of the first dimension and the second dimension comprises an arrangement such that the third electronic unit is arranged parallel to the first electronic unit and the fourth electronic unit is arranged parallel to the second electronic unit. According to another preferred embodiment of the invention, the angled or perpendicular arrangement of the first dimension and the second dimension comprises an arrangement such that the impedance of the series of the third electronic unit and the fourth electronic unit is arranged electrically in parallel to the impedance of the series of the first electronic unit and the second electronic unit.

According to yet another preferred embodiment of the invention, each electronic unit is arranged on a conductive resistive substrate. Preferably, the conductive resistive sub- strate corresponds to an insulating plate such as a glass plate having a conductive layer adapted for conducting electrical current.

According to yet another preferred embodiment of the invention, the management unit comprises a detecting unit adapted for detecting a change in a physical parameter of an electronic unit. The physical parameter can be an electrical parameter. Most preferably, the management unit further comprises a control unit adapted for addressing an electronic unit and for controlling the physical parameter to be in a predetermined range, wherein the predetermined range depends on a regulation strategy for the physical parameter. The term "adapted for addressing" also comprises the meaning "configured to address", i.e. "the control unit adapted for addressing an electronic unit" comprises the meaning that "the control unit is configured to address an electronic unit". Preferably, the management unit further comprises a decoding unit adapted for decoding a command being addressed to an electronic unit. In other words, each electronic unit of the plurality of electronic units comprised by the electronic array shows a management unit that shows the following capabilities: Each management unit decodes the command which is addressed to it, for instance via a decoder that can be implemented as a microcontroller. The management unit uses the necessary portion of the electric current which flows through it for fulfilling the function of the electronic in dependence upon the command addressed to it, via for instance a power driver. Furthermore, each management unit dissipates the surplus or excess portion of the electric current which flows through it via for instance a variable resistive element, such as a varistor, shunting the basic component or basic electronic unit, respectively.

It is noted that the minimum size of the electronic array is preferably two times two, i.e. two columns of two components which are connected in series to each other. According to yet another preferred embodiment of the invention, the physical parameter comprises at least one of electric current, electric voltage, temperature and impedance. Most preferably, the electronic unit comprises a light emitting device such as at least one of an organic light emitting diode and a light emitting diode.

According to yet another preferred embodiment of the invention, the management unit further comprises a second control unit adapted for generating an open circuit if an electronic unit malfunctions. Preferably, the management unit further comprises a dissipation unit adapted for dissipating a surplus of the physical parameter, preferably an electric current and/or an electric voltage, if a neighboured electronic unit being in series or in parallel to the electronic unit comprised by the management unit malfunctions.

The management unit can be constructed so that it is less likely to break-down than the original simple electronic unit which does not comprise a management unit. Therefore, in case a given electronic unit is malfunctioning by a short-circuit, it is placed in open circuit and there is no increase in the electric current feeding the electronic units of a column nor any decrease in the electrical current feeding neighbouring electronic units. Additionally, in case of a malfunction of the open-circuit type in a given electronic unit, as the extra current is dissipated separately in each neighbouring electronic unit, no additional electric stress is generated in the neighbouring electronic unit.

According to a preferred embodiment of the invention, the array is a regular electronic array of LEDs. Accordingly, conventional LEDs are associated with the management unit described, whereby each LED is voltage controlled. If an LED goes short-circuit, the improved LED detects its malfunction and goes open-circuit. If an LED goes open- circuit, the neighbouring LEDs receive an additional extra current from the faulty column. This additional electric current is diverted via a shunt resistance and the brightness of these LEDs remains unchanged.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with ref- erence to the embodiments described hereinafter.

In the drawings:

Fig. 1 shows a first conventional solution;

Fig. 2 shows a second conventional solution;

Fig. 3 shows a management unit according to a first embodiment of the invention;

Fig. 4 depicts an electronic array according to a second embodiment of the invention;

Fig. 5 shows a regulation strategy according to a third embodiment of the invention;

Fig. 6 shows the available ranges of electric current according to the third embodiment of the invention; and

Fig. 7 shows the different ranges of operation according to the third embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Similarly, it is to be noticed that the term "coupled", also used in the claims, should not be interpreted as being restricted to direct connections only. The terms "coupled" and

"connected", along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression "a device A coupled to a device B" should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. "Coupled" may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all fea- tures of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodi- ments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Furthermore, some of the embodiments are described herein as a method or combina- tion of elements of a method that can be implemented by a processor of a computer system or by other means of carrying out the function. Thus, a processor with the necessary instructions for carrying out such a method or element of a method forms a means for carrying out the method or element of a method. Furthermore, an element described herein of an apparatus embodiment is an example of a means for carrying out the func- tion performed by the element for the purpose of carrying out the invention.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

The invention will now be described by a detailed description of several embodiments of the invention. It is clear that other embodiments of the invention can be configured according to the knowledge of persons skilled in the art without departing from the true spirit or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

In the following the invention is described in the case of an electronic array comprising at least two dimensions, wherein in each dimension identical or nearly identical elec- tronic units (for instance each electronic unit comprises one single color LED or a RGB LED) are arranged preferably on a conductive resistive substrate such as glass comprising a conductive layer adapted for conducting electricity. The two dimensions may be defined by Cartesian co-ordinates or polar co-ordinates, for example. The electronic array comprises a plurality of electronic units wherein each electronic unit comprises a management unit. Most preferably, the connection method used is the connection method described in connection with Fig. 2. The invention may be applied to a panel of laminated glass, comprising a first panel of glass, a second panel of glass, and a plasties interlayer, wherein the first panel of glass and the second panel of glass are laminated together via the plasties interlayer. One glass panel (the conductive resistive substrate) has a conductive layer, preferably a transparent conductive layer and the conductive layer is patterned to make the conductive paths, e.g. by laser ablation. The electronic units and components are arranged on the conductive layer and connected thereto and are laminated between first and second panels of glass. The invention may also be applied to all kind of panel comprising at least one conductive resistive substrate, for instance in a double glazing panel comprising a glass made conductive resistive substrate (first glass panel) carrying the electronic units, an air gap and a second glass panel, the air gap being sandwiched between the first and the second glass sheet and the electronic array being provided on the first glass panel and in the air gap between the first and second glass panel.

The conductive layer is preferably provided as coplanar and/or thin tin oxide films, e.g. indium tin oxide (ITO) films, and may be applied by any suitable method such as chemical vapour deposition (CVD) coatings or magnetron (sputtered) coatings, thus providing an electrically conductive layer. The conductive layer can also be provided as metallic layer(s) or layer(s) made of any suitable electrically conductive material. The conductive layer can also be applied by other methods such as serigraphy, screen printing, and other suitable method. For instance, the conductive layer may comprises an underlying coating comprising a conductive oxide such as silicon oxide carbide and an overlying coating comprising a conductive metal oxide such as SnO₂IF. The conductive layer may also comprises a substantially color neutral coating stack, e.g. a chemical vapor deposition (CVD) coating stack comprising a silicon oxide carbide undercoat and an overlying SnO₂:F coating, wherein the coating has preferably a resistance of about 15 ohms per square.

According to the first embodiment of the invention and as shown in Fig. 3, a management unit which is associated with or included in an electronic unit comprises a detect- ing unit 5 adapted for detecting at least one representative information relating to a malfunction of the given electronic unit, for instance by detecting changes in a physical parameter, such as temperature, impedance, electric voltage or electric current. Furthermore, the detecting unit 5 is preferably adapted to detect at least one information representative of a malfunction of a neighbouring electronic unit, for instance by detecting a change in the electric current received, which is indicated as reference numeral 9 in Fig. 3. Further, the management unit comprises a second control unit adapted for generating an open circuit of the given electronic unit if the electronic unit malfunctions or does not work properly. This is done, for example by opening a switch 8. Moreover, the management unit comprises a dissipation unit adapted for dissipating a surplus of a physical parameter such as an electric current that is received in the event of a malfunction of the neighbouring electronic unit, for instance via a resistive element shunting the basic component 3. This is indicated as reference numerals 4 and 6 in Fig. 3. The management unit decodes the command which is addressed to it via a microcontroller 7 that is also shown in Fig. 3. It is noted that putting the electronic unit into short circuit is not optimal, as in this case the neighbouring electronic unit would receive less electric current, which can hardly be corrected in contrast to a surplus electric current which could always be dissipated.

An electronic array according to a second embodiment of the invention is shown in Fig. 4. Fig. 4 shows the basic circuit 16 comprising a plurality of electronic units. The power pins 10, 11 indicating a power supply unit are also shown in this figure. The basic circuit 16 comprises a control unit 12, a driver unit 13 and a load 14. Furthermore, the basic circuit 16 also comprises the control of the power supply unit, i.e. the regulation of the operational voltage that is done by ICl, R2, R3 and R4. It also includes means for diversion of the current surplus that can be done by a switch such as a transistor Ql, and the resistance Rl. A system for measuring the operational parameters can comprise resistances R5 and R6 and the analog-to-digital converter (ADC), and in addition the resistance Rl together with another ADC. The system for controlling the operational volt- age optionally comprises a digital-to-analog converter (DAC) and the resistance R7. The switching unit 15 is also shown in Fig. 4. The switching circuit 15 comprises a switching transistor Q2 for switching between the basic circuit 16 to the electronic array. Furthermore, the switching circuit 15 comprises a system for measuring the total current given by the resistance R8 and IC3. Moreover, it comprises a logic circuit for checking the switching and given by IC2 and the supply for the switching circuit 16 given by the resistance R9, Dl and C2.

Considering that the supply management circuit is a switch operating in a binary way, one can ignore it in a first approximation with respect to the functioning of the entire circuit. The external simplified model of the circuit shown in Fig. 4 is analogous to an adjustable Zener diode that is almost perfect in its operation. Indeed, if one considers that i_lin is a constant electric current supplied to the circuit and that the functional part of the circuit consumes a current i₂ constantly varying but always smaller than i_lin, and i₃ represents the surplus current i_lin - i₂ being variable as well. Furthermore, neglecting the effect of the resistance R2, ICl will on the other hand regulate i₂ so that its control volt- age remains equal to its internal reference voltage. According to the second embodiment of the invention, the internal reference voltage optionally corresponds to 2.5 V for a given model of ICl. In this manner, the electronic unit will be seen externally as showing a constant impedance, regardless of the consumption of the applicative part of the circuit. The electronic circuit shows a large gain, the dynamic impedance of the circuit is clearly weaker than the one of a real Zener diode, whereby the electric voltage remains vertically constant independent of the electric current flowing.

The operational electric voltage of the circuit is set by the resistances R3 and R4 in the following manner, whereby the resistance R7 is neglected in a first order approxima- tion:

U = V_ref ICl x (R3 + R4)/R4.

Typically, if R3 equals R4 and V_ref ICl equals 2.5 V, the resulting regulated electric voltage U would equal 5 V. Preferably, R3 and R4 are selected such that the electric current i₂₃ is neglectable with respect to i₂. Due to the nature of the circuit, i₂₃ remains constant. One requirement of the circuit is to be able to modify its characteristic impedance for influencing the electric current i_lin once the latter is determined by natural distribution in the electronic array. Indeed, in order for each electronic unit comprised by the electronic array to function normally, each of them must show a substantially identi- cal electric current i_lin. However, this is not necessarily the case because of the problems in manufacturing tolerance of the circuits or topological positioning or defects in the electronic array.

The problem described is solved by modifying the regulating voltage of the feeding circuit in a defined way. Slight variations in operational voltage have a direct impact on the distribution of the electric current between the different equipotential elements of the electronic array. The electric voltage variation is achieved by modifying the balance of the bridge comprising the resistances R3 and R4 and by injecting a small positive or negative electric current into the connection R3 - R4. In this way, a slightly higher elec- trie voltage or slightly lower electric voltage can be generated. This is implemented by the DAC generating an electric voltage in a range lying symmetrically around the reference voltage of ICl and leading the control electric current through the resistance R7. An important condition for the proper functioning of the circuit is that it can deal with the lowest electric voltage without any consequence on its functioning. This implies that a small extra electric voltage range must be provided besides the one strictly necessary for the operational part. As a default, the operational electric voltage will be set at a mid level of the extra range and will be increased or decreased depending on the requirements or needs, respectively. In the circuit according to the second embodiment of the invention, there is an average operational electric voltage of V volts, e.g. 4.75 V as de- fault which could be adjusted in the range between V ±5% or V+10% or V ±15%, e.g. 4.5 V to 5 V.

Another function of the feeding circuit or supply circuit, respectively, consists in diverting the part of current i_lin which is not used in the load 14, globally represented by i₂. The latter electric current can be subdivided in three parts as shown in Fig. 4. One part i₂₂ is associated with the functioning of ICl, another very small part i₂₃ is necessary for the voltage divider R3 - R4. There is also a path for diverting the electric current that is potentially too large for being processed completely by ICl. This is implemented by the resistance R2, the transistor Ql and the resistance Rl. The electric voltage at the contacts of R2 is representative of the electric current absorbed by ICl, and, hence, repre- sentative for the regulation process or regulation scheme, respectively. Thus, a transistor will amplify the effect of ICl, whereby the transistor will divert the surplus electric current through the resistance Rl. Should there be a surplus electric current causing an increase of the general voltage of the current, then ICl would react by trying to absorb it via the resistance R2. This generates an increase of V_be at the contacts of the transistor Ql which reacts by strongly increasing the current flowing therethrough. In this way, one obtains an electric voltage at the contacts of R2 which is practically constant and equivalent to the voltage V_be of the transistor. By selecting an appropriate value for R2, the average operational electric current of ICl is fixed and the variation of the electric current is absorbed by Ql - Rl.

An effect of the implementation of this circuit is that the electric voltage at the contacts of Rl is the exact representation of the current available for the application in case of varying load. Hence, one can obtain a characterization of the function by measuring the operational voltage and the available current. It is worth noting that the operational voltage is fixed by the control DAC. However, this is only as much as the environment of the electronic unit comprised by the electronic array allows obtaining it.

Having provided an electronic unit that allows setting of the operational voltage in order to divert the unused electric current and providing the information about the operational voltage and the available electric current, one still has to determine the control strategy or regulation strategy, respectively, for the operational voltage or any other physical parameter to be used, in order to be implemented as a function of various operational parameters. This regulation strategy, also referred to as regulation scheme, is now going to be described with reference to the third embodiment of the invention as illustrated in Figs. 5 to 7. If an electric voltage is applied to the electronic array comprising a plurality of electronic units, a total predefined electric current is injected. The electric voltage of the electronic units is increased to the voltage set in the middle of the variation range. According to the third embodiment of the invention, the middle of the variation range corresponds to V, e.g. 4.75 V. If the electronic array is in a perfect state of operation and additionally neglecting side effects, the electric current is distributed in an equiva- lent way amongst all electronic units comprised by the electronic array.

The following defects can occur: An electronic unit is short-circuited or consumes too much current. In this case it would drain a part of the current dedicated to its neighbouring electronic units. Furthermore, it would cause an electric voltage drop at its contacts which would have repercussions on its neighbouring electronic units. An electronic unit is open-circuit, i.e. it does not take up its electric current which is then deviated to the remaining equipotential electronic units.

By performing an analysis of the operational voltage and of the unused current in the electronic unit, it becomes possible to partly determine the defects in the neighbourhood of the electronic unit and to determine the type of defect. Therefore, this would allow providing a reaction to the problem by modifying the operational voltage of the electronic unit.

According to the third embodiment of the invention, the control unit has to implement the regulation strategy according to certain criteria defined hereinafter. Fig. 5 shows six different ranges for the operational voltage. Range 1 corresponds to the range between 0 V and V₁. In this range, the voltage is too low for a proper functioning of the electronic unit. Thus this range should be avoided by disconnecting the electronic unit. Range 2 comprises the range between Vi and V₂ indicating that the voltage is sufficient for the decision-making process of the supply controller or control unit, respectively, but insufficient for managing the operation of the electronic unit. Range 3 comprises the range between V₂ and V₃ and shows that the voltage is sufficient for managing the operation of the electronic unit but with some limitations. Range 4 comprises the range between V₃ and V₄ and indicates that the electronic unit can function normally. Range 5 comprises the range between V₄ and V₅ and indicates that there is slight overvoltage to be corrected in an attempt to come back to range 4. The functioning is allowed but makes additional checking for a physical parameter, such as dissipated power or temperature, to become necessary. Range 6 indicates the range between Vs and Vβ and represents that the voltage is too large. The integrity of the electronic unit is questionable, thus it a safety procedure must be initiated, e.g. either reducing the operational voltage to come back to range 5 or by disconnecting the electronic unit. The operational voltage is limited by an external protection circuit aiming at limiting the maximum voltage at the contacts of the electronic unit. According to the third embodiment of the invention, the electronic unit corresponds to a transient voltage suppressor (TVS). According to other preferred embodiments, the electronic unit corresponds to a varistor.

According to the third embodiment of the invention and as shown in Fig. 5, it is worth noting that the regulation strategy of the supply voltage in the electronic unit shows only an effect in the ranges 4, 5 and 6. Other than this, it is the electronic array which dictates the operational voltage. According to the third embodiment of the invention and as shown in Fig. 6, also the available current can be analysed to find an optimal operational range. It is normally expected to have an electric current which is precisely defined upon starting. In operation, it is possible to dynamically indicate to the electronic unit via a data bus which current the electronic unit is supposed to manipulate and thus to adapt the distribution of the electric current during the operation in accordance with the requirements demanded. The diagram shown in Fig. 6 shows the available ranges for the electric current. I_cmp represents the total current passing through the electronic unit. I_rsv represents the reserve current measured at the resistance Rl. I_ro corresponds to a reserve of zero current.

The six different ranges according to the third embodiment of the invention are going to be described in connection with Fig. 6. Range 1 indicates the current between zero amperes and Ii . In this range, the electric current is too low for anything to function in the electronic unit. This range has to be avoided, i.e. the electronic unit has to be discon- nected. Range 2 comprises the range between Ii and I₂ and indicates that the current is sufficient for the decision-making process of the supply controller, but insufficient for managing the operation of the electronic unit. In this range, the functionality of the electronic unit has to be kept deactivated. Range 3 comprises the range between I₂ and I₃ and indicates that the voltage is sufficient for managing the functionality of the electronic unit but with some limitations. Range 4 comprises the range between I₃ and I₄ and indicates that the electronic unit functions in a nominal way. Range 5 comprising the range between I₄ and I₅ and indicates that there is a slide overcurrent or surplus current, respectively, to be corrected in an attempt to come back to range 4. The functioning is allowed but makes additional checking for physical parameters, such as for dissipated power or temperature, necessary. Additionally to precautionary measures linked to the power, it is desirable to reduce the current as it potentially represents a need for other electronic units arranged in parallel. Range 6 comprises the range between I₅ and Ie and indicates that the current is too high. The integrity of the electronic unit is questionable in this range, therefore a safety procedure should be initiated such as reducing the operational voltage in order to come back to range 5 or disconnecting the electronic unit.

When putting the two diagrams shown in Figs. 5 and 6 on top of each other, it becomes possible to determine the regulation strategy to be applied by the control unit. This is shown in Fig. 7 also representing the third embodiment of the invention. The different ranges of operation are now going to be described in connection with Fig. 7. Range 1 indicates that the electric current and/or the electric voltage are/is insufficient for the electronic unit to function properly. The electronic unit has to be disconnected in this range. Range 2 shows that the current and/or the voltage is sufficient for managing the supply but insufficient for managing the application. Therefore, the functionality of the electronic unit must be deactivated. Range 3 shows that there is enough current and voltage for activating the functionality of the electronic unit but with some limitations. The operational voltage for improving either the available voltage or the current has to be varied as a function of the type of application. Range 4 indicates that the voltage is sufficient but the current is insufficient for having the application functioning fully. The voltage has to be regulated so as to keep it at its acceptable minimum threshold, i.e. at V₃, and so as to increase the current at the same time. Range 5 indicates that the current is sufficient but the voltage is insufficient for having the application functioning fully. In this range, the electric voltage has to be increased in order to reach the acceptable lower limit I₃ for the electric current. One could even go lower than this lower limit, but then one would come back to range 3. Range 6 indicates that the current and the voltage are in appropriate operational ranges. This is the optimum operational range. Range 7 indicates that there is enough voltage to have the electronic unit functioning but there is too much current. The voltage has to be regulated in order to reduce the current so as to come back to range 6. Finally, range 8 indicates that the voltage and the current are too high for guaranteeing the integrity of the electronic unit and the electronic unit has to be disconnected from the electronic array.

In general, priority is given to an adequate regulation of the electric current. The oblique lines in the diagram of Fig. 7 represent possible variations of the operational point with respect to its ideal position when varying the operational voltage. The causes for the offset of the operational point with respect to its ideal position have been determined. Therefore, it has become possible to evaluate the possible defects in the electronic array in the neighbourhood of the electronic unit under test. This is going to be described in the following in connection with Fig. 7.

Range 3 indicates that V < V₃ and I < I₃ and represents that the voltage and the current is too low. This is caused by a short-circuit in the lateral equipotential neighbourhood of the electronic unit. The lower these values, the closer the short-circuit is. Range 4 indicates V > V₃ and I > I₃ and represents that the voltage is right or too high but the electric current is too low. This is caused by a short-circuit in the lateral neighbourhood of the electronic unit or in the very close neighbourhood in the levels above or beneath in the electronic array. Range 5 indicates V < V₃ and I > I₃ and represents that the voltage is too low but the current is sufficient. This is caused by an open-circuit of an electronic unit located above or below in the electronic array. Finally, the upper part of the range 7, i.e. V > V₄ and I > I₄, indicates that too much current and voltage is present. This is caused by a laterally neighbouring electronic unit in open-circuit or a vertically adjacent electronic unit that is short-circuited. It is worth noting that a finer discrimination can be made by measuring a second operational point on the same curve for a given electronic unit. This would allow even more precisely to quantify where the defect is located as well as to determine the type of defect. The supply control unit manages the operation ranges 2 to 8.

The principal or basic component will also manage the functionality and may cause in certain detection events an immediate stop to become necessary. For instance, through monitoring temperature by means of an integrated sensor a defect in a part of the circuit can be detected, for instance an impedance outside the tolerances of the load. It is the switching circuit which will manage both cases by controlling the functionality of the main circuit.

The switching circuit must keep the switch closed as long as the main circuit shows a continuous and expected activity on one of its outputs such as Xdata. The control circuit shows the following functionalities: It ensures the connection of the electronic unit at the starting-up, it performs a check at the starting-up in order to ensure that the operational point is valid, it disconnects the electronic unit if it seems defective at the end of the starting-up test, it disconnects the electronic unit in operation if it does not show any activity anymore on the Xdata line, it continuously measures the operational current, it disconnects the electronic unit if the current is abnormally high, it disconnects the component if the operational voltage is too high and it maintains the electronic unit disconnected until the switching-off of the system.

The operational principle is described in the following in connection with Fig. 4: When the voltage is applied to the system, transistor Q2 is opened and a small electric current is supplied to the circuits IC2 and IC3 by the electronic array via resistance R9 and Dl. C2 ensures a provision of charges IC2 and IC3 operating autonomously for some time. If the operational voltage U_sup is in a range which is valid for the integrity of the electronic unit, transistor Q2 is closed in a measurement of current I_sup that is made quite rapidly after closing the transistor. Various cases may present themselves then: Firstly, voltage and current can be in the normal ranges of tolerance with respect to the prede- fined levels for the starting-up. Ql remains closed in this case. Secondly, the voltage can drop and the current can be too high. Then, the electronic unit is short-circuited. Ql is re-opened and the voltage drops at the contacts of the electronic unit and also produces a defect in supplying the switching circuit. This is the reason why Dl isolates the circuit from the rest and allows it to function autonomously with the energy stored in C2 until Ql is re-opened, which will eliminate the short-circuit. Thirdly and finally, the voltage can remain too high and the current too low. Then, the electronic unit is in open-circuit. Ql is re-opened as the electronic unit cannot function anyway.

Once the starting-up test is finished, the ranges are extended to the maximum voltage and electric current which can be coped with by the principle or basic component. It is the latter which will instruct the switch to cut or stop, respectively. If the electric voltage or the electric current are above the range what is manageable by the principal component, Q2 will be systematically opened and will maintain in this state. Once Q2 is re- opened, it cannot be closed again to get the switching-off of the system.

It is noted that the electric current measuring resistance R8 shows an impedance which does not exceed a few mega ohms. The voltage U_sns at its contacts may thus be considered to be negligible in any scenario. This voltage is amplified with a very important factor by IC3 for being measurable by IC2, i.e. I_sup. The resistance R9 shows a relatively large value. Independent of the electronic unit that is defective in the switching circuit, a simple circuit defect can only generate at most a total or partial disconnection of the electronic unit comprised by the electronic array, thus avoiding a large propagation of the defect in the neighbouring electronic units of the electronic array.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodi- ments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practising the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A single unit may fulfil the functions of several items recited in the claims. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An electronic array comprising: a power supply unit (10, 11), a first electronic unit and a second electronic unit in a first dimension, wherein the first electronic unit and the second electronic unit each comprise a management unit, and the first electronic unit and the second electronic unit are arranged in series to each other, further comprising a third electronic unit and a fourth electronic unit in a second dimension, wherein the second dimension is arranged at an angle to the first dimension, wherein the third electronic unit and the fourth electronic unit each comprise a management unit, and the third electronic unit and the fourth electronic unit are arranged in series to each other.

2. The electronic array according to claim 1, wherein the angled arrangement of the first dimension and the second dimension comprises an arrangement such that the third electronic unit is arranged parallel to the first electronic unit and the fourth electronic unit is arranged parallel to the second electronic unit.

3. The electronic array according to claim 1, wherein the angled arrangement of the first dimension and the second dimension comprises an arrangement such that the impedance of the series of the third electronic unit and the fourth electronic unit is arranged parallel to the impedance of the series of the first electronic unit and the second electronic unit.

4. The electronic array according to any of the preceding claims, wherein each electronic unit is arranged on a conductive resistive substrate.

5. The electronic array according to claim 4, wherein the conductive resistive substrate corresponds to a glass panel having a conductive layer adapted for conducting electricity.

6. The electronic array according to any of the preceding claims, wherein the management unit comprises a detecting unit adapted for detecting a change in a physical parameter of an electronic unit.

7. The electronic array according to claim 6, wherein the management unit further comprises a control unit adapted for addressing an electronic unit and for controlling the physical parameter to be in a predetermined range, wherein the predetermined range depends on a regulation strategy for the physical parameter.

8. The electronic array according to one of claims 6 and 7, wherein the management unit further comprises a decoding unit adapted for decoding a command being addressed to an electronic unit.

9. The electronic array according to one of claims 6 to 8, wherein the physical parameter comprises at least one of electric current, electric voltage, temperature and impedance.

10. The electronic array according to any of the preceding claims, wherein the electronic unit comprises at least one of an organic light emitting diode and a light emitting diode.

11. The electronic array according to one of claims 6 to 10, wherein the manage- ment unit further comprises a second control unit adapted for generating an open circuit if an electronic unit malfunctions.

12. The electronic array according to one of claims 6 to 11, wherein the management unit further comprises a dissipation unit adapted for dissipating a surplus of the physical parameter, preferably an electric current and/or an electric voltage, if a neighbored electronic unit being in series or in parallel to the electronic unit comprised by the management unit malfunctions.

13. The electronic array according to any of the claims 5 to 12 wherein the glass panel is a first glass panel and is laminated to a second glass panel with the electronic array laminated between the first and second glass panel.

14. The electronic array according to claim 13, wherein the first and second glass panel are laminated together with a plastic sheet laminated therebetween.

15. The electronic array according to any of the claims 5 to 12 wherein the glass panel is a first glass panel and is associated to a second glass panel with the electronic array being provided on the first glass panel and in an air gap between the first and second glass panel.