WO2016165820A1

WO2016165820A1 - System and method of operating thereof

Info

Publication number: WO2016165820A1
Application number: PCT/EP2016/000599
Authority: WO
Original assignee: Scora Bvba
Priority date: 2015-04-13
Filing date: 2016-04-12
Publication date: 2016-10-20

Abstract

The system of a first and a second display devices is configured for display of data portions of a single data set available in the memories of the first and the second display devices, such that the display screen of the first display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device. Thereto, the system carries out a method comprising the loading header data from the data set; the exchange of information between the display devices by means of the communication units for coordination of the data portions to be displayed; the formatting of the data portions to be displayed in accordance with settings of the display devices, and the displaying the data portions on the display screens. Each of the display devices comprises thereto processor, a memory, a communication unit, a display screen and a user interface.

Description

SYSTEM AND METHOD OF OPERATING THEREOF

FIELD OF THE INVENTION

The invention relates to a system of a first and a second display device, each display device comprising a processor, a memory, a communication unit, a display screen and a user interface.

The invention further relates to a method of operating thereof.

BACKGROUND OF THE INVENTION

In recent years, portable computers and the components used therein have been undergoing size reduction, which has given rise to a new format of computer known as a tablet. This type of device is commonly used for presentation of pictures, films and other visual material, including books. Another promising application of tablets is the display of music scores, so that musicians need no longer to play from music scores on paper.

The provision of a system for digital music scores, particularly for use in classical music, demands very high standards of operation, so as to prevent that one of the display devices would fall out during a performance. Particularly in larger groups, such as orchestras and quartets, the failure of one selected display device may well cause the orchestra to interrupt its performance. Furthermore, it is desirable that the operation of a digital score deviates musicians not more and preferably less from playing than the existing paper scores, where it is necessary to turn over a page in the course of a longer score.

Therefore, it would be desirable to create a larger flexibility, since there is a variety of situations, wherein musicians perform in the absence of a conductor. Furthermore, the music written for some instruments, such as organ, piano and percussion, is composed of several musical lines, such that a very large display would be needed to provide the musicians with the overview that they are used to, for instance by playing from a score in book form or in the form of a series of pages coupled together by means of some adhesive tape. SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an improved system of display devices, , which is optimized for playing by an ensemble without predefined conductor or by an individual who needs to have overview of data that cannot be displayed properly on a screen of a single display device. More particularly, it is an object of the present invention to provide such a system wherein the display of the portions of the score on different displays is coordinated. Furthermore, it is an object to provide such a system that is configured for the performance of music scores by an ensemble and/or a single individual person.

It is a further object of the invention to provide a method of operating such a system.

In accordance with a first aspect, the invention provides a system of display devices, each display device comprising a processor, a memory, a communication unit, a display screen and a user interface, which memories of the display devices are provided with a data set for display in the course of time upon receipt of instructions, wherein the first and the second display devices are configured for information exchange between the communication units of the display devices such that the display screen of the first display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device.

In accordance with a second aspect, the invention provides a method of operating a system of a first and a second display device, each display device comprising a processor, a memory, a communication unit, a display screen and a user interface, which memories of the display devices are provided with a data set for display in the course of time upon receipt of instructions, comprising the steps of:

Loading header data from the data set;

Exchange of information between the display devices by means of the communication units for coordination of the data portions to be displayed;

Formatting of the data portions to be displayed in accordance with settings of the display devices, and

Displaying the data portions on the display screens,

wherein the coordination is carried out such that the display screen of the first display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device.

The invention is based on the insight that the display of complementary data portions on the screens of separate display devices requires coordination between them. Thereto, in accordance with the invention, the display devices are configured for exchange between the devices, particularly in a wireless manner. Based on accurate organisation of the data set that is present in the memory of each display device, exchange of limited data, particularly so- called metadata rather than content, may be sufficient for the coordination. Particularly, the metadata - also referred to as header data - are to indicate location information within the data set. The location information is more particularly an indicator of the order in the data set, when displayed on the screen. The order may for instance be defined per paragraph, for instance sign 28 of paragraph 11. Exchange of information between the display devices on the subdivision of the data set, then allows each processor to display the assigned data portion, for instance a plurality of paragraphs. In a preferred embodiment, therefore, the data set is subdivided into data blocks that are sufficiently small in comparison to the size of the display screen such that the data portion to be displayed can be formatted, rather than being shown as a single picture.

In a suitable embodiment of the device, hierarchy identification means are present, which are configured for identifying a hierarchy between the display devices, such that a first display device adopts a master mode and any second display device adopts a slave mode. The advantage of such hierarchy identification means is that a single display device is identified as the leading device, more particularly operating in the master mode, and which display device will be the follower device, more particularly operating in the slave mode. The advantage hereof is that no user instruction may be required for coordination of the operation of the display devices.

In a further preferred embodiment, the display devices are provided with a monitoring state and with a confirmed state, wherein the devices, initially being in a monitoring state, adopt a confirmed state upon confirmation of the hierarchy by the other display device. The state of the display devices may be controlled in the hierarchy identification means, but alternatively by the processor. This embodiment allows an operation mode wherein no second display device available. Particularly, the first display device may already adopt the master mode before a second display device is ready. The second display device later joins in slave mode.

In a further embodiment of the invention, the method comprises the steps of:

monitoring by all active display devices and identifying a hierarchy between the display devices, such that a first display device adopts a master mode and any second display device adopts a slave mode, wherein the hierarchy identification means, initially being in a monitoring state, adopt a confirmed state upon confirmation of the hierarchy by the other display device; initialising the display devices under control of the first display device, such that any second display devices process the same data set in a synchronized way;

receiving or reading a user instruction, and if the user instruction is read or received in the second display device, transmitting this instruction to the first display device; - displaying complementary data portions of the data set on the display screens of the first and any second display device under control of the first display device.

Thus, more particularly, therefore, the method according to the invention comprises a plurality of stages:

a monitoring stage, carried out by all active display devices, wherein after identification of another display device the hierarchy between the display devices is identified;

an initialisation stage, wherein the display device in the master mode provides instructions such that the processors of all display devices process the same data set and are synchronized;

a progress stage, wherein all display devices may receive instructions from a user, via internal or external user interfaces, which instructions are transmitted to the processor of the display device operating in master mode, and wherein the display of the data portion progresses in accordance with user instructions and/or a predefined programme, and optionally

a termination stage, wherein a hierarchy between the display devices is cancelled and/or the displaying of data portions on the data screens is terminated.

In a specific embodiment, the monitoring comprises:

Adopting the monitoring state;

- Monitoring receipt of an instruction via the user interface, via any other interface or via the communication unit;

Transmitting monitoring information to identify the second display device;

Upon receipt of a response to the monitoring information or upon receipt of an instruction, or upon detection of absence of response or instruction within a predefined duration, adopting an operation mode;

Upon receipt of a response to monitoring information from the second display device, switching from the monitoring state to the confirmed state;

According to this embodiment, the monitoring not merely comprises monitoring of other display devices, but also monitoring for user instructions. The operation mode is then chosen in dependence of the receipt of any answer. Suitably, the feasible operation modes are master mode and slave mode. It is however not excluded that a further mode may be chosen. In a further implementation, the monitoring uses a dedicated wireless protocol arranged for monitoring and exchange of small messages, such as Bluetooth Low Energy. Alternatively, use can be made of identification protocols, such as NFC and MIFARE. The latter may be feasible for a situation wherein two displays are used adjacent to each other. The mutual distance is then small and identification protocols, typically based on transponder technology, may be used. The distances could be further reduced in that the display devices are each provided with more than one antenna, that are arranged on side faces that are expected to face a neighbouring display device, if any one thereof is available. It is feasible that the further transmission of data runs via a different wireless protocol. In addition to using a wireless protocol, use could be made of wired communication. The exchange between the display devices may be a direct exchange or be an exchange via a third device, i.e. a wireless access point. However, in an alternative implementation, the full communication between the display devices maybe carried out via a protocol, such as Bluetooth messaging, that is merely provided with limited bandwidth and data size. In this alternative implementation, the information transmitted between the display devices is suitably limited to address and timing information and verification protocols. Such information may be written in a condensed manner, particularly in combination with further software that has been written into the memory of the display devices. If there would be a need for downloading additional data sets, such as for instance a different music score, this would be achieved by means of internet downloading or the like.

After definition of the hierarchy, the master may transmit instructions to the slave, and therewith control that any desired information is shown on the display screen of the display device operating in slave mode. However, the transmission of the instructions is not merely a transmission of information in a broadcasting manner, as the data portion to be provided on the display screen of the display device in the slave mode is to be different and

complementary to the data portion to be displayed on the display screen of the display device in the master mode. Moreover, in the event that the system comprises a third display device in addition to the first and the second display device, the data portion to be shown on the display screen of the third display device is again different from that to be shown on the first and on the second display devices.

In one embodiment hereof, the instructions comprise a programming and an update, wherein the programming defines a series of individual data portions within the data set to be displayed on the screen, and wherein the update specifies which individual data portion is to be displayed at a certain timing. The series of individual data portions are for instance embodied as the paragraphs discussed before. This subdivision enables that the amount of data to be transmitted in the course of operation can be kept small, and may thus be provided at a small bandwidth or even in a messaging protocol with a maximum content size per message. It is observed that this control by means of updates is enabled by the fact that the data sets are anyhow available on the memories of the first and the second display device. The programming may be specified on the basis of header data of the data set. The programming could be updated in the course of the operation.

In one further implementation, the processors of the first and the second display devices are configured for formatting the data portion to be displayed on their own screen. This formatting occurs on the basis of location information in the data set, and on the basis of initialisation data, that suitably have been provided by the device in master mode during the initialising stage. Alternatively, the first display device is configured for formatting the data portion to be displayed on the screens of all available display devices. The transmitting instructions then indicate the data portion to be displayed in the desired format. As discussed before, this involves the paragraphs, but also the ordering of a suitable number of signs within the paragraph onto the display screen. Such may for instance be, in the example of music scores, the position of individual lines in the score while scrolling over the screen, and a separation shown on the screen between one page and a subsequent page. This implementation may have the advantage that there is no need for loading the complete data set into the processor of the first display device (in master mode) in an initialising stage. It is sufficient that the processor loads certain data portions from the memory, and provides instructions to the second display device on the basis thereof.

In again a further option, the processor operating in master mode may, upon loading header data of the data set during initialisation, decide that the processing will be divided between the processors of the first and the second display device. In this manner, optimum use of available processing capacity is achieved. With the term 'header data' reference is made to data in a general portion of the data set, which indicates size and subdivision of the data set. Since all display devices are suitably provided with a communication unit and means for acting in master mode, the first device in master mode may specify a 'sub-master' for predefined portions of the data set, and to format such data portions on the basis of the information shared during the initialisation stage, such as clock information and information on the display settings. More particularly, it is deemed suitable that the processor is configured for generating series of data portions for display during the period that such data portions are shown and the system waits for further user instructions. Such generation typically involves the generation of the layout, dependent on the display settings into images ready for display, for instance in the form of bitmaps. The generated data sets are then stored in a memory. Once needed, they maybe used. This is deemed to increase the operation speed of the system, particularly in response to a user instruction of scrolling back and/or forth through the full data set. It is further preferred that these images will be stored in the memory. Suitably, the memory is stored and configured for storage of this images. For instance, the memory may be provided with memory blocks (for instance separate memory ICs, or a partition) which is dedicated for such images, and thus also configured for effective storage and retrieval thereof.

In the course of displaying complementary data portions on the screens, the user interfaces of the first and the second display devices are suitably both active. Since a user is typically not aware which of the display devices acts in master mode and which in slave mode, the user will not be motivated to provide instructions via a user interface only. Moreover, the most handy manner of giving instructions may depend on the user (musician) as well as the data set (music score), so that it may well be beneficial that user interfaces on both display devices, and typically at least partially embodied as a touch screen, remain active. In order to ensure that control is maintained, the slave mode is configured such that upon receipt of a user instruction, it will forward this in any suitable form to the master. In dependence of implementation and the type of user instruction, the processor operating in slave mode may process instructions or portions thereof. In one embodiment, the master sends a response to the slave upon receipt of the forwarded user instruction. Such a response indicates to the slave that the user instruction is received. The processor in slave mode may then decide to discard the user instruction from a - temporary - memory, and consider itself no longer responsible for the user instruction. If however no response is received, the slave may conclude that the communication does not work. An algorithm may then be started such that the second display device leaves the slave mode and processes the user instruction.

For such situation, it is deemed beneficial that the communication is controlled in that the individual display device may be in a monitoring state and a confirmed state. In the monitoring state, the display devices are not connected and the processors work separately, while monitoring for other display devices. In the confirmed state, the display devices are connected and one thereof acts as a master to control the operation. Hence, if the second display device transmits a user instruction, but does not obtain a response, it will leave the confirmed state and fall back into the monitoring state. While being in the monitoring state, it will execute the user instruction. It may then in the monitoring state adopt a master mode. As such, the first display device that previously acted in the master mode may then change over to a slave mode.

Preferably, at least some of the data portions that have been displayed on the screen of a display device are stored in a temporary memory of the display device. More particularly, the these data portions may be data portions at the beginning of the data set or at the beginning of one or more subsequent paragraphs. This storing of some selective data portions, or even all data portions, enables that the selective data portions may be shown again on the display screen with very limited delay, when receiving a user instruction to go back to a selected data portion. Thereto, in a further implementation, the data portions that have been shown on the screen are labelled with a number before such temporal storage. Additionally, the user interface is configured so as to enable to scroll through the numbered pages. The user may then give the instruction to return to a desired page, which may be loaded from the memory.

BRIEF INTRODUCTION OF THE FIGURES

Fig l diagramatically shows a system with a first and a second display device, and

Fig.2 shows a flow diagram;

Fig.3 shows a first part of the flow diagram of Fig. 2 specifying the monitoring stage;

Fig. 4 shows a second part of the flow diagram of Fig. 2 specifying the initialization stage; Fig. 5 shows a third part of the flow diagram of Fig. 2 specifying the further stages DETAILED DISCUSSION OF ILLUSTRATED EMBODIMENTS

The figures are purely diagrammatical and intended for illustrative purposes only. Same reference numerals in different figures refer to same or corresponding parts.

Figure l shows a system 100 according to a first embodiment of the invention comprising a first display device 20 and a second display device 120. Each of the display devices is provided with a a processor, a memory, a screen, a user input and a

communication unit, as known per se. Such devices are known per se, for instance from Samsung as Galaxy™ TAB S 10.5 Wi-Fi. The general operation of such display devices is also known per se. The display screen is suitably of a size of at least As-format and may be larger. The user interface is generally incorporated in the display as a touch screen. Furthermore, keys may be available for switching the display on and off. It is feasible that a further user interface is provided, such as a pedal (a foot interface), or an interface operated on the basis of vision and/or sound as known per se. Another option for a further user interface is a proximity sensor, which is not meant to exclude any other suitable type of interface. Such interface is deemed beneficial for the playing music, as a musician does not need any longer to use his hands for turning a page, or requesting a screen setting.

According to the invention, the system 100 is configured such that the display devices are configured for operating in a complementary way. More particularly, the system is configured such that complementary data portions of a data set stored in the memory are displayed on screens arranged adjacent to each other. It is herein preferred that refreshment of data on the screen, particularly to display additional data not displayed before, is coordinated, i.e. that the refreshment on the screens occurs at least substantially

simultaneously. Thereto, each of the display devices is preferably configured such that the processors of each display device may receive and send instructions via the communication unit to adjacent display devices 20, 120. More specifically, the display devices may operate in a master mode and in a slave mode. In the slave mode, a screen of the display device is operated on the basis of instructions received from a display device in the master mode. In the master mode, the processor provides instructions as to displaying of first and second portions of the data set on the screens of the first and the second display devices 20, 120. In the following, it is assumed that the first display device 20 acts in master mode (also called master) and the second display device 120 acts in slave mode (also called slave).

The communication from the master to the slave may be arranged in a suitable manner, such as known per se from communication via a bus, such as the l2C-bus. The system maybe configured such that the 'master' sends out a message to the 'slaves' regularly or only when a change is needed, or in accordance with a communication of both. Suitably, each display device is provided with a separate address or identifier, such that the slave may identify whether a message is relevant for him or not. The communication may be optimized that the required bandwidth will be limited. This allows that the information may be sent wirelessly without high data transmission rates, or even in accordance with a wireless protocol that merely allows limited bandwidth.

In a preferred embodiment, the system is however further configured such that messages may be transmitted from the slave to the master. In one embodiment, such messages are confirmation messages that the second display device 120 is still present and operating. In another and important embodiment, the system is configured such that the second display device 120 may transmit messages following receipt of user instructions from a user interface that is part of or coupled to the second display device 120. Such messages may be

transmitted via the same protocol or a different protocol. If the same protocol is used, this protocol preferably comprises a separate channel for the communication from slave to master. In such a mode, the conventional 'decoding' of a user instruction by the processor into appropriate instructions to any elements of the second display device 120 may thus be switched off. Instead merely a single output is given in the form of a message to the master. It will be apparent, that various implementations and alternatives are feasible here: the processor could merely forward the instruction, or decode the instruction and translate it into one or more messages of a predetermined format and content. Furthermore, the processor could store the content in its memory, at least during a limited period, so as to reduce processing. Also, it could be that - dependent on the user instruction - the processor of the second display would already process it or certain portions thereof. For instance, if the user instruction 'next page' would be received by the second display device 120, it could be configured to read the next page from its memory already, such that the first display device 20 would merely need to transmit the exact timing of its displaying. The data set is for instance a music score, Beethoven's fifth pianoconcerto. Herein, it is very beneficial that the music may be shown on two screens simultaneously, and with

simultaneous movements. However, the data set may alternatively be a book, a series of texts or otherwise. Preferred is however a data set that may be subdivided into portions, for instance paragraphs, comprising a plurality of signs to have a predefined order within a paragraph. In addition to music, text formats for which the system is highly beneficial are text in scriptures that are essentially based on pictograms, such as Chinese, Korean and Japanese scriptures. The benefit of the present system is that it allows for displaying the data portions at a desired magnitude and with a desired and variable distance between lines on a screen. In fact, the formatting of the data portion may be carried out in the course of displaying rather than by displaying a single picture that fills a full screen. However, it is not excluded that the data set is configured of a plurality of data blocks in the form of pictures with a size sufficiently small to facilitate a versatile displaying on the screens.

For sake of simplicity, the system will be explained for the embodiment that two display devices are arranged adjacent to each other. It is however not excluded that the system would be formed by three or more display devices. It is assumed in the following that the relevant data set has been loaded into the memories of the display devices, and that display devices are further provided with software for displaying the data set. Fig. 2 shows a basic flow diagram for a first embodiment of the method of the invention. As will be apparent, the method generally comprises at least four stages. The first stage 1 is the monitoring stage, so as to define a hierarchy between the display devices 20, 120. The second stage 2 is an initializing stage, wherein the master initializes the second display device 120. The third stage 3 involves reading and/or receiving a user instruction. The fourth stage 4 involves displaying of complementary data portions on the screens of the display devices 20, 120. It is to be understood that the third stage 3 does not necessarily follow on the initializing stage 2 and is not necessarily followed by the display stage 4. Rather, a user instruction may be achieved already in the monitoring stage 1 and/or the initializing stage. Furthermore, the system may be configured to move to the display stage 4 immediately after the initializing stage 2, and to wait for a user instruction only thereafter. In this and following figures, the first display device 20 is shown in the left hand column and the second display device 120 is shown in the right hand column. Only a first and a second display device 20, 120 are shown herein, which does not exclude the presence of more devices.

Fig. 3-5 show in more detail the monitoring stage 1, the initialisation stage 2 and the further stages 3, 4 in the first embodiment shown in Fig. 2. These will hereinafter be discussed one by one. As will be apparent from Fig. 5 and Fig. 2, the display stage 4 is herein a subsection of the third stage 3. Furthermore, a further fifth stage 5 is shown, as another subsection, which relates to the addition of annotations. Such annotations to the original text can be seen as a specific type of user instruction, i.e. not to change the displaying of the data set, but to add information to the data set.

The monitoring stage 1 is preferably carried out by all the available display devices 20, 120, at least during a certain predefined period of time. This is desired, since the system 100 should be able to cope with the situation of merely a single operating display device. The system is furthermore preferably configured to allow the addition of an auxiliary display device into the system after start up. The monitoring stage 1 may be carried out by means of a specific identification protocol, such as NFC or the Bluetooth™ Low Energy protocol. The transmission via this latter protocol is in the form of ultrashort messages, also known as 'beacons'. Such a beacon message suitably fits within a so-called AdvData field, which can contain o to 31 octets of data, therewith limiting the data space to 31 octets. In use, a beacon generation device will transmit a beacon message using a low energy protocol, which allows a limited transmission range from the beacon generation device, for instance up to 5 meters. Any properly configured device within the said range can receive the beacon message.

Suitably, this receiving device is configured that it will carry out certain actions upon receipt of the message automatically. A particular application in the field of advertisement is known from US2013/0065584A1. When using such low energy protocol, inclusion of other devices into the system may be prevented in several ways, for instance by using a specific bandwidth, or by requiring an authentication on the basis of data available in the memory of the display devices of the system. It will be understood that several levels of authentication are feasible here, for instance (1) display devices that have been operated in a single system before, (2) display devices that meet the system requirements, which however have not been operated in a single system before.

In order to carry out monitoring, the display devices are suitably provided with monitoring means, such as RF transmission electronics, for instance an antenna, an RF IC for

(up)converting any instruction to any RF signal in a predefined communication band, and for downconverting any RF signal to a message, optionally a power amplifier, as well as with any software needed therefore. Such monitoring means typically involve RF integrated circuits as known per se to the skilled person. It is not excluded that the monitoring means are integrated into a communication unit for wireless communication, rather than being a separate device or set of devices. Upon receipt of a monitoring message, suitably the receiving, second display device transmits a response. When the response is received by the first display device, and the second display device can be authenticated, the display device may switch from a monitoring state to a confirmed state. Suitably, this switch may involve that a different communication protocol is used for the subsequent communication between the display devices. However, this is not deemed necessary. The monitoring is thereafter cancelled in one implementation. In an alternative implementation, the frequency of sending out monitoring messages is reduced.

Options for such subsequent communication may be the use of a conventional wireless network, using an access point, the use of another wireless protocol, as well as the use of a communication arrangement that is at least partially embodied in the form of a wired network. For instance, the system may be further configured with a printed circuit board, that is - in use - to be arranged so as not to cover part of the display screens. The printed circuit board is for instance arranged at a rear side or at a bottom side or at a top side. Such a printed circuit board may be configured such that it enables fixation of the display devices onto a standard or on the plate of a piano destined for holding scores. It is suitably provided with a cover or a package. The printed circuit board may further be provided with additional electronic components, for instance to allow wireless charging of the display devices. Further options will be apparent to the skilled person. The display devices are for instance, in one embodiment fixed to the printed circuit board by means of magnets, but other fixation mechanisms for temporal and removable fixation will be apparent. Several protocols may be used for the definition of a hierarchy between the display devices 20, 120 in the system. Options are a chronological order of receiving a monitoring message; a predefined hierarchy between the display devices 20, 120 as stored in the memory; the adoption of a hierarchy on the basis of a preceding seance of joint operation in the system, unless actions have occurred; reception of a user instruction on one of the display devices; the connection of an external user interface device to one of the displays. The

implementation of such protocol will be apparent for the skilled person.

Notwithstanding this variety of options for identification of the hierarchy, it is desired to carry out monitoring so as to identify the number of display devices in the system. It is not deemed necessary that this monitoring is carried out continuously by all display devices.

Clearly, the monitoring may be carried out intermittently (with a predefined frequency), and/or during a limited period only. For instance, a display device pre-programmed to act in the slave mode, may carry out monitoring in a first period, so as to verify that there is no further display device. Optionally, the monitoring is dependent on the hierarchy in a preceding seance, user instruction or system set up (for instance with an external user interface device).

As shown in more detail in Fig. 3, the method more specifically involves, in one example embodiment, the monitoring (and/or offering of service) by the first display device 20, and optionally also the second display device 120. This information is present as a beacon, a service identifier or the like. Upon discovery of such monitoring request, the second display device 120 returns a connection request. Thereafter, the display devices 20, 120 engage in a subphase called 'connection set up'. This typically involves the transmission of a verification request, the sending of credentials in response, the acceptance of the connection and the acknowledgment thereof. Furthermore, the connection set up may include an authentication. Such authentication is particularly useful so as to enable the set up and initialisation for first and second display devices that have been used in a single system before. The authentication typically involves the identification of an device identifier and the reference in the memory, whether the said device identifier is known and what data sets have been used already.

Optionally, such authentication process could also result in exchange of the roles of master and slave, in order to be able to use information and settings available in the memories of the display devices in a most optimal manner. The verification stage 2 may include several tasks to ensure that the system is properly configured and can be controlled by the first processor. Some of these tasks may be on system level. For instance, it is desired that the operation of the processors is synchronized, or at least that a dedicated clock is installed which is followed by both processors. Further verifications may be carried out, for instance for verifying that the version of the data set in both display devices is the same. Other tasks may require that feedback from a user, i.e. a user instruction triggered by a message displayed on at least one of the screens, at least in specific system configurations. For instance, in the absence of sensors identifying whether the second display device 120 is present at the left or the right hand side of the first display device 20, it is deemed appropriate that a message is displayed on the screen so that the user confirms the arrangement of the display devices 20, 120. Additionally, the screens of the displays may be configured in this stage. For instance, a user interface defined on the display screen may be configured to be placed only on the screen of the first display or the screen of the second display. This configuration may be triggered on the basis of user instructions, but may be arranged on the basis of predefined settings read from a memory. Furthermore, such verification stage may also require identification of the settings of the display screens of the displays, and additionally, ensuring correct settings allowing displaying of complementary portions. For instance, the data portions of the data sets are to be shown on the screens with predefined and coordinated sizes. Typically, one size would be used for all data portions, even though it is not excluded that different sizes are used. Additionally, the display may be dependent on user settings: data portions may be shown page by page. Alternatively, data portions may be displayed by means of scrolling. When showing data portions page by page, the turning of a page may result in two new pages being shown or rather just one, with the other page shifting, typically from right to left.

As shown in more detail in Fig. 4, the initialisation stage 2 may involve a first and a second subphase. The first subphase 21 is the screen initialization. The second subphase 22 involves data initialization. This second subphase 22 involves in the embodiment shown a specific implementation wherein the master transmits the data set, particularly in the form of pre- configured data portions ready for display. However, there may well be alternative embodiments wherein this data initialization is carried out differently, and/or involves the transmission of some parameters, such that the second display device 120 can generate such data portions on its own. Furthermore, the initialisation stage 2 could further involve a processing management initialisation, wherein the processor of the second display device 120 is given specific processing tasks so as to prepare some of the data portions for the entire system. Particularly, the screen initialization 21 typically involves the transmission of secondary screen information, such as size and resolution from the second to the first display device. Thereafter, the first display device 20 returns display parameter to be used (including width, height and colors) and user preferences.

The data initialisation 22 typically involves, in one embodiment, the transmission of available data, and return of data available in the memory (cache), i.e. in a form (as data portions) ready for display on the screen. Thereafter, further data of the data set are transmitted from master to slave. The receipt of that information is suitably acknowledged. Finally, the instruction is given by the master to delete any preceding data set, which information is again acknowledged by the slave.

The reception stage 3 involves the reception of a user instruction. It is typically started with the detection of a user instruction, or the preparation of the device thereto. Rather than waiting for a user instruction, the system may be programmed to continue by itself at a specified pace, i.e. to display a subsequent data portion on the data screens based on other signals. One such signal is for instance the passing of a marker in the data set, for instance added during initialisation stage. Such marker may then be used as a signal to start displaying a next data portion. The marker could also be used for transmitting timing instructions, i.e. the master may indicate to a slave that he should proceed to the marker, if the slave would not be there. One other option is that the system has been initialized to start displaying a subsequent data portion, unless a user instruction is received that indicates otherwise. If preparation is needed (i.e. the user interface needs to be woken up), the processor may be provided with means for estimating a time of expecting a user instruction. A score is typically subdivided into a plurality of bars. When it takes 1 minute to play the first 30 bars that are a data portion that is simultaneously displayed on the screens, it maybe expected that the second 30 bars would take again 1 minute, unless a second portion of the score arrives with an indication of a different rhythm and speed. Thus, in one specific embodiment, the processor of the display device may estimate when to expect a user instruction. This process is shown in Fig. 5 in more detail. The first and the second display devices 20,

120 thereto contain direct user interfaces 29, 129. Furthermore, the first display device 20 is in this embodiment provided with a remote or external user input 39. This could

alternatively be coupled to the second display device 120. When the second display device 120 receives a user input, this is processed in the processor 128, and thereafter transmitted via communication unit (not shown) to the first display device 20 as input signal 140. This input signal 140 may be transmitted in a raw form or a filtered form. Suitably, as shown in this figure 5, the input from the second display device 120 is considered as a remote input and is processed in the same way and/or in the same sub-unit as information from any external user input. It is then transmitted to the processor 28 of the first display device 20 for processing. Of course, it will be understood that the information from the second display device 120 could also be transmitted directly to the processor 28.

On the basis of the user instruction as received from any source 29, 129, 39, the processor may then start further actions. Action I involves the opening of a data set. Action II involves the display of certain portions of a data set that has already been opened. Action ΠΙ involves the addition of annotations.

As discussed hereinabove, the reception of a user instruction at the slave, involves the transmission thereof or at least one message corresponding therewith to the master. In addition to detecting user instructions with respect to the data portions to be shown on the screens, user instructions may be given to add notations and/or other remarks. As a result hereof, the thus modified data set needs to be stored in the memory. In this situation, the modification needs to be processed by the processor, both of the slave device and of the master device, and it needs to be transmitted to the other device, particularly by means of specifying the location in the data set, and the modification. In one implementation, the notations are stored in a separate notations file that is displayed on the screen in an overlying manner with the original data set, for instance the score. The process of adding annotations in shown in more detail in subsection 5.

The displaying stage 4 involves the transmission of instructions from the master to the slave and the displaying. Particularly the transmission involves instruction of data portions to be shown, for instance by means of locations (addresses), and instruction of timing

information. In one embodiment, the timing and the data portions are transmitted together. In an alternative embodiment, the timing is transmitted separately from the data portions. It is feasible, that the initialising phase comprises the transmission of a programme, wherein the data set is subdivided into a series of data portions that are to be displayed on the screen of a specified display device in a certain order. The transmission of instructions during the displaying stage 4 may then be limited to the transmission of timing information and optionally an identification of the data portion to be displayed. This minimizes demands of bandwidth of wireless communication. It is observed for clarity that clock information may be implemented in various manners. A dedicated clock could be prescribed both in the master and the slave, for instance in the form of a counter, wherein the master sends out instructions on updating the counter. Such updates may be necessary in view of inherent variations between oscillators defining the clocks in the display devices. Alternatively, the clock information could be configured on the basis of markers added into the data set. The master may then specify the point when the data portion at the marker (or the instructions corresponding thereto) are to be executed. Furthermore, the clock information may be in the form of instructions to process data at a relevant point in the data set.

As shown in Fig. 5 in relation to the subsection of the display stage 4, this process typically involves, in one embodiment, in the master 20, a memory 22 (data set server), a visibility controller 23, a commander 24 for the second display device, and a display screen 25 (any needed electronics to do the displaying therewith being included). The second display device 125 also has a display screen 125. It will have other elements, which are however not indicated herein. The visibility controller 23, the commander 24 and the processor 28 may well be integrated into a single device as functions rather than as devices.

The visibility controller 23 is the key component or function for an ongoing display, as it controls the display on the display screens 25, 125, and defines any instructions for improvement. For the second display screen 125, this is carried out via commander 24. The commander 24 suitably provides the conversion to transmit instructions 141 and/or 142. Instructions 141 relate to display specific data portions having a predefined layout.

Instructions 142 relate to temporal or spatial positions within the data set, so that the second display device 120 can identify which data portions to display.

The visibility controller 23 is instructed by the processor after opening a data set. The opening of a new data set is also communicated to the second display device 120. The second display device 120 thereafter carries out an algorithm, to identify the presence of such data set, its retrieval (from memory or optionally from an external server, by wireless or wired communication). If available, an acknowledgement will be given. As to the annotations sections, this follows typically, in one embodiment, an algorithm involves annotation command detection, annotation processing, and display updating. Again in line with the process identified as signals 141 and 142, the resulting annotation data 143 maybe either transmitted separately, or it is generated into a revised data set, which is - in its entirely or only as some portions thereof - transmitted as a data set update 144. The data set of the second display device 120 is then updated, and the display on the screen can be updated. Thus in summary, the system of the invention comprises a first and a second display devices and is configured for display of data portions of a single data set available in the memories of the first and the second display devices, such that the display screen of the first display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device. Thereto, the system carries out a method comprising the loading header data from the data set; the exchange of information between the display devices by means of the communication units for coordination of the data portions to be displayed; the formatting of the data portions to be displayed in accordance with settings of the display devices, and the displaying the data portions on the display screens. Each of the display devices comprises thereto processor, a memory, a communication unit, a display screen and a user interface.

Claims

1. System of a first and a second display devices, each display device comprising a

processor, a memory, a communication unit, a display screen and a user interface, each of which memories of the display devices is provided with a data set for display in the course of time upon receipt of instructions, wherein the first and the second display devices are configured for information exchange between the communication units of the display devices, such that the display screen of the first display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device.

2. System as claimed in Claim l, wherein the first and the second display devices are provided with a hierarchy identification means being configured to identify whether the display device is to operate in a master mode or a slave mode.

3. System as claimed in Claim 2, wherein the hierarchy identification means is provided with a monitoring state and a confirmed state, said hierarchy identification means of the first display device is configured to switch from monitoring state to confirmed state upon receipt of a confirmation of the operation mode from the second display device.

4. System as claimed in Claim 3, wherein the processors of the display devices are

configured for transmission of clock information upon switching to the confirmed state while in the master mode to another display device in slave mode.

5. System as claimed in Claim 2 or 3, wherein the processor is configured for receiving and transmitting information defining locations in the data set for the data portion to be displayed and for defining timing information for updating the data portion, wherein the processor is configured for receiving information when operating in the slave mode, and is configured for transmitting information when operating in the master mode.

6. System as claimed in any of the preceding claims 2-5, wherein the processor is

configured for receiving a user instruction from the user interface, and wherein, when a display device operates in the slave mode, the received user instruction is transmitted to the display device acting in the master mode.

7. System as claimed in any of the preceding claims, wherein the communication unit of the display devices are provided with first communication means configured for a first wireless communication protocol and second communication means configured for a second wireless communication protocol.

8. System as claimed in Claim 7, wherein the first communication means is used for monitoring availability of any other display device and for defining hierarchy between the displays.

9. System as claimed in any of the preceding claims, wherein the display device is

provided with a displaying face, and rear face opposed thereto, and a pairs of opposed side faces, wherein the communication unit of the display device is provided with a first and a second antenna arranged at opposed side faces and configured for receiving and transmitting data from a neighbouring display device.

10. System as claimed in any of the preceding claims, wherein the data set represents a music score for at least one instrument, for instance a piano.

11. System as claimed in any of the preceding claims, further comprising a foot interface to be operated by at least one foot, such as a pedal, which foot interface is coupled to one of the display devices and used as an input of user instructions.

12. System as claimed in any of the preceding claims, wherein at least one of the display devices is provided with a means for speech recognition, which means are configured for receiving user instructions, particularly in relation to timing information for updating the data portion.

13. A method of operating a system of a first and a second display device, each display device comprising a processor, a memory, a communication unit, a display screen and a user interface, which memories of the display devices are provided with a data set for display in the course of time upon receipt of instructions, which method comprises the steps of:

Loading header data from the data set;

Exchange of information between the display devices by means of the

communication units for coordination of the data portions to be displayed; Formatting of the data portions to be displayed in accordance with settings of the display devices, and

Displaying the data portions on the display screens,

wherein the coordination is carried out such that the display screen of the first

display device displays at a first point in time a data portion of the data set that is complementary to a data portion of the data set displayed by the display screen of the second display device.

14. The method as claimed in Claim 13, comprising the steps of:

- monitoring availability of display devices and identifying a hierarchy between the display devices, such that a first display device adopts a master mode and any second display device adopts a slave mode;

- initialising any second display device under control of the first display device, such that all display devices process the same data set in a synchronized way;

- receiving or reading a user instruction, and if the user instruction is read or

received in any second display device, transmitting this instruction to the first display device, and,

- displaying complementary data portions of the data set on the display screens of the first and any second display device under control of the first display device.

15. The method as claimed in Claim 14, wherein the monitoring comprises

- Adopting the monitoring state;

- Transmitting monitoring information to identify the second display device;

- Upon receipt of a response to the monitoring information or upon receipt of an instruction, or upon detection of absence of response or instruction within a predefined duration, adopting an operation mode;

- Upon receipt of a response to monitoring information from the second display device, switching from the monitoring state to the confirmed state;

16. The method as claimed in Claim 14 or 15, wherein the displaying of complementary data portions comprises, in the first display device, if in the confirmed state:

- monitoring user information,

- defining first and second data portions to be displayed on the displays of the first and the second display device, in accordance with user instructions;

- displaying first data portions on the display, and - transmitting instructions to the second display device for display of the data set on its display.

17. The method as claimed in Claim 13-16, wherein the displaying of complementary data portions comprises, in the second display device

- receiving instructions from the first display device;

- displaying data portions on the display screen in accordance with the received instructions.

18. The method as claimed in any of the claims 14-17, wherein the instructions

transmitted from the first display device to the second display device comprise information defining locations in the data set for the data portion to be displayed and for defining timing information for updating the data portion.

19. The method as claimed in any of the claims 14-18, wherein the initializing comprises transmitting clock information to the second display device.

20. The method as claimed in any of the claims 14-19, wherein the hierarchy

identification means of the display devices are preprogrammed such as that a specific display device adopts by default the master mode to become the first display device.

21. The method as claimed in any of the claims 14-20, wherein a display device is

configured to start operating in the master mode, upon detection of absence of response from any other display device within a predefined duration and/or upon receipt of an instruction from a user before reception of a response from any other display device.

22. The method as claimed in any of the claims 14-21, further comprising the steps of terminating the display and cancelling the hierarchy between the display devices.