Tactile acquisition device comprising an alignment of tactile sensors
Patent Information
- Application Number
- FR2023002676
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-03-22
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2043-03-22
Smart Images
Figure 00000016_0000
Abstract
Description
Title of the invention: Touch acquisition device comprising an alignment of touch sensors Field of invention
[0001] The present invention relates to the field of series of tactile sensors, making it possible to capture by a simple interaction a time-stamped acknowledgment of the execution of a task, and optionally the location of the acknowledgment.
[0002] A particular and non-limiting application concerns signage for guiding an operator to a designated location. These solutions, known under the English name "pick-to-light", are particularly suitable for reducing the number of movements in the warehouse and are part of the techniques to be adopted to improve the efficiency of operators by going so far as to eliminate purchase orders.
[0003] For such applications, light beacons equipped with buttons are integrated into the front of each of the channels of the dynamic shelving and are controlled by the warehouse management software which controls their state in order to indicate to the operator that goods must be extracted from a channel and specifies the number of units to be picked. The picker then scans the destination location of the goods: this can be the shelf of a removal trolley, a bin (or drawer), or directly the order package. When he has extracted the desired units, he presses a key to inform the warehouse management system (WMS, acronym for the English term "Warehouse Management System") of the execution of the operation, then the light signal goes off. The beacons where the products to be collected are located automatically light up when a new order must be prepared.
[0004] To prepare several orders at once with one or more operators performing the tasks at the same time (it is possible to assign a light beacon to each user or a color to each user). Therefore, the more operators working at the same time, the more profitable this system is.
[0005] Alternatively, the use of these solutions also allows the reloading of the bins, then being designated by the English term "put-to-light". The light system indicates to the order picker the number of references to be placed in each package or compartment of the shelf.
[0006] Conventional pick-by-light or put-to-light systems consist of individual electronic devices, with which this optical signaling is guaranteed for each shelf compartment. These systems are fixed either individually or in suitable strips in the form of a housing on the shelf.
[0007] Each storage space is identified by an LED affixed to a shelf or a condi operation in the form of a strip comprising a network of LEDs each controlled by a microcontroller. This strip comprises a printed circuit which is itself connected to a server by a radio-frequency link or by a wired link. The server addresses one or more LEDs to be activated by a coded signal, for example in PWM phase width modulation or more simply by NRZ coding (acronym for the English term "Non Return to Zero"). It is thus possible to control by a simple link the activation of any one of the LEDs or of a set of LEDs, the activation consisting of controlling its switching on or off, or even its color when the LEDs are of the configurable multicolor type.
[0008] Acknowledgment of the withdrawal can be carried out by detecting the presence of the operator in front of the bin concerned, for example by a proximity sensor, or by a button activated by the operator, on an individual box comprising the indicator of the quantity to be withdrawn.
[0009] Generally speaking, the invention aims to provide a ribbon comprising a series of aligned touch sensors to allow rapid installation on an area to be controlled, preferably in a modular form allowing several elements to be chained together to form a longer series. State of the art
[0010] Patent EP2061991B1 is known describing an integrally formed single-piece LED light strip containing a conductive base comprising first and second bus members formed from a conductive material. The bus members distribute power from a power source to LEDs that are mounted on the first and second bus members so that they draw power from and add mechanical stability to the first and second bus members. The integrally formed, flexible single-piece LED light wire is assembled such that the first and second bus members are connected to each other before mounting the LED and this integrally formed single-piece LED light wire is formed without a substrate.
[0011] Patent application DE202018002291U1 proposes the use of LED strips with individually addressable LEDs for identifying individual shelf compartments in shelves, characterized in that specific shelf compartments can be individually identified by the targeted activation of individual LEDs of such an LED strip.
[0012] Patent JP2006347670 describes a display device consisting of a push button and a 4- to 7-segment LED. The illuminated push button indicates that the coin is being picked up by the operator when the button glows. When the operator picks up the coin, he presses the button to clearly indicate that the coin has been removed. The 4- to 7-segment LED indicates the number of coins picked up by the segment.
[0013] Patent JP2006248735 also proposes a “pick-to-light” solution implementing a plurality of devices installed in parallel are provided in each picking zone of the picking device. When the picking of the delivered goods is finished, an operator intervenes to confirm that the picking is finished by actuating a picking end button.
[0014] Patent application US20060197474Al describes a modular LED strip, comprising a multiple conductor wire, including a common data wire, and a plurality of nodes, arranged along the multiple conductor wire. Each node comprises an LED and a node microprocessor, having a unique address. The node microprocessor is configured to independently control the illumination of the LED according to node-specific operating instructions that are transmitted via the common data wire.
[0015] Patent FR3059130B3 describes a device for guiding light to a person in a storage room over a large area. This device comprises an electronic communication box which provides a TCP / IP and UDP / IP protocol, an internal bus and one or more electronic boxes in order to control addressable LED strips.
[0016] Patent FR3055453B3 describes a device for assisting order preparation by light guidance on a low-cost mobile order preparation trolley. This device comprises a wireless electronic communication box which provides a TCP / IP and UDP / IP protocol in order to control addressable LED strips. Disadvantages of the prior art
[0017] The solutions of the prior art are not entirely satisfactory because the configuration of the series of sensors is fixed and does not allow any flexibility. To equip a larger control zone, the only solution is to
[0018] For signage applications, it is difficult to synchronize the state change command of the diodes with the action of the operator.
[0019] The proposed solutions are relatively complicated to install and require complex cabling between the WMS server and the various shelves.
[0020] A secondary problem concerns the integration of the buttons in the indicator for locating the compartment to be sampled or loaded and the ease of handling when the operator is wearing gloves, as well as the sensitivity to external disturbances, in particular electromagnetic fields. The solutions of the prior art generally provide “indicator-acknowledgement button” assemblies in the form of individual boxes, which complicates installation and connection to the WMS central unit. Solution provided by the invention
[0021] In order to overcome the drawbacks of the prior art, the present invention relates to in its most general meaning a tactile acquisition device comprising an alignment of tactile sensors characterized in that it comprises a printed circuit comprising an alignment of N tactile sensors each connected by a track to a controller delivering on a BUS track of said printed circuit a digital signal as a function of the identifier and the state of the corresponding sensor as well as an identifier of said device, said BUS track being capable of being connected either to a server or to another device to form a chain of tactile sensors.
[0022] Advantageously, said sensors (11 to 14) consist of conductive electrodes formed on the surface of said printed circuit, each of said conductive electrodes being connected by a conductive track to a capacitive contact microcontroller.
[0023] Preferably, said conductive electrodes are formed by a conductive surface surrounded by an insulating peripheral zone separating it from a conductive ground plane formed on the surface of said printed circuit.
[0024] According to a variant, said conductive electrodes have a surface area of between 50 mm2 and 500 mm2.
[0025] According to a variant, said conductive electrodes are coated with an elastically deformable insulating material.
[0026] Preferably, said conductive electrodes form an alignment with a pitch of between 10 and 100 mm, and a space between two consecutive electrodes of between 3 and 10 mm, the pitch of said alignment of electrodes being identical to the pitch of said alignment of light-emitting diodes,
[0027] Advantageously, said length of the connecting tracks from the conductive surface to the microcontroller being less than 200 mm.
[0028] Preferably, said light-emitting diodes are controlled by a common NRZ coded signal.
[0029] The invention also relates to a signaling system comprising a touch acquisition device mentioned above, characterized in that it further comprises an alignment of N light-emitting diodes arranged on a printed circuit, each of said light-emitting diodes integrating a controller controlling its state as a function of a coded signal transmitted by a track of said printed circuit.
[0030] Advantageously, said alignments of sensors and said alignments of light-emitting diodes are produced on a common printed circuit.
[0031] According to a variant, said sensor alignments and said light-emitting diode alignments are produced on a common flexible printed circuit, with common electrical supply tracks for said sensor alignments and said LED alignments.
[0032] According to another variant, said alignments of sensors and said alignments of light-emitting diodes are produced on two adjacent separate printed circuits.
[0033] Preferably, said alignment of N light-emitting diodes is associated with an alignment of acknowledgment sensors each arranged near one of said light-emitting diodes, said sensors being associated with at least one controller delivering a signal on one of said tracks of said printed circuit according to the identifier and the state of the corresponding sensor.
[0034] According to a particular embodiment, each printed circuit has at its two lateral ends, a connector, male on one side of the alignment of LEDs and / or touch sensors and female on the other side, for connecting the power and data tracks to the power and data tracks of a consecutive printed circuit, for chaining the elements, or for connecting the element closest to the server to said server.
[0035] Detailed description of a non-limiting example of embodiment
[0036] The present invention will be better understood on reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:
[0037] [Fig.l] [Fig.l] represents a schematic view of a signage strip according to the invention General principles of the invention
[0038] The general principle of the invention relates to strips, preferably flexible, of aligned touch sensors which can be connected to a server by only three wires, two wires for power supply and one wire for signal transmission (or possibly local power supply and wireless transmission), and which can be chained to form longer series of sensors, without hardware modifications to the strips, and in a self-configured manner.
[0039] The device is constituted by a printed circuit, preferably flexible, having an alignment of acquisition zones each connected by a printed track to a microcontroller, the printed circuit further having two power supply tracks (a ground track (2) and a track (2) connected to a voltage source typically), and a track (1) forming a data bus connected to the output of the microcontroller (10). The tracks (1 to 3) preferably terminate at the edges on either side of the alignment of acquisition zones at connecting pins, for the connection of a connecting cable connecting the acquisition device to a server or to another chained acquisition device, to form a cascade of devices connected to the server by a single link, the microcontrollers of each of the devices being automatically configured according to the signals present on the data bus (1).
[0040] The acquisition zones can be made up in different ways: contactor, formed for example by a deformable metal sheet capable of ensuring contact with the printed circuit (5), resistive sensor, inductive sensor, infrared sensor, surface acoustic wave (SAW) sensors... Capacitive sensors
[0041] As indicated previously, different sensor technologies are possible, and in particular, for their capacity for integration into a flexible system with a flexible printed circuit, resistive or capacitive touch sensors.
[0042] A resistive sensor is a transducer or electromechanical device that converts a mechanical change, such as displacement, into an electrical signal that can be processed after conditioning. These passive sensors are the most widely used in instrumentation.
[0043] After a study of the different resistive sensors and the possible diversion of their “classic” use, only the resistive sensor with touch strip was retained. Indeed, the other sensors did not present any viability with regard to our project, in particular due to their high cost.
[0044] The resistive sensor is in the form of two parallel strips separated by an air gap. When an object presses on the upper strip, it will come into contact and close the circuit to form a voltage divider bridge. It is then sufficient to measure the out voltage to determine the contact position. This sensor is thus similar to a linear potentiometer.
[0045] Such a sensor can be integrated into the signaling system by depositing on the printed circuit, between two conductive tracks, an elastic support of resistive strip extending between the two conductive tracks, and an insulating strip with a window opening onto a conductive strip. By pressing on the surface of the resistive strip, the assembly deforms and the resistive strip comes into contact with the conductive strip. The outer strip is typically polypropylene (transparent) or opaque Kapton HN (trade name), and the conductive strip is an adhesive copper strip or a PCB copper rod or a copper sheet. The resistive strip is for example a magnetic ribbon.
[0046] The preferred embodiment uses capacitive sensors whose principle is based on the variation in capacitance of an electrode caused by the proximity of a finger to the latter. This technology does not require a mechanical element, thus offering very good durability. It also makes it possible to create very free sensor shapes, thus adapting to different use cases.
[0047] There are two implementations of these capacitive sensors.
[0048] The first is of the intrinsic capacity type (in English "Self capacitance"), and is made up of an electrode (copper surface), having its own capacity (facing the ground plane). When a user approaches the sensor, the field lines emitted by the electrode are disturbed, thereby increasing the equivalent capacity of the electrode (parallelization of the own capacity of the electrode and the intrinsic capacity of the user). It is then sufficient to measure this variation in capacity to detect a press, the design of the buttons is very simple because only one electrode is needed to make a sensor. With this method, each button (electrode) will emit field lines in the form of a sphere, this limits the proximity of the buttons to each other, because they interfere with each other.
[0049] The second solution is called Mutual Capacitance and is based on the implantation of two electrodes, one emitting and one receiving. The field lines are guided between the two electrodes and, unlike intrinsic capacitance, the equivalent capacitance decreases when a user brings his finger closer to the touch zone. The fact that the field lines are guided between the two electrodes makes it possible to increase
[0050] the button density without increasing the risk of coupling too much.
[0051] This technique requires 2 control pins per sensor (Rx and Tx electrodes). This This method allows you to create button matrices, thus allowing you to manage a large number of sensors with a reduced number of controller pins.
[0052] The first solution (intrinsic capacitance) is particularly suitable for the invention because it allows a single electrode to be formed per sensor, simply by a metallized area of the printed circuit. It also has good sensitivity.
[0053] Each sensor (11 to 14) consists of a metallized electrode formed on the printed circuit (5). Common shapes are solid discs, squares and rectangles, fitting into a surface area of 8 to 20 mm on each side. The choice of size makes it possible to optimize sensitivity and latency: Sensors with a large surface area have a larger default capacitance, and this effect is amplified if other sensors are nearby. A large sensor will have a larger time constant, which leads to longer charging, discharging and measurement times. This then increases latency and consumption. A larger sensor will be more sensitive.
[0054] It is preferable to sufficiently space the electrode from the edge of the board. The use of ground plane (3) between the electrode and the edge of the board improves noise immunity.
[0055] Each electrode (11 to 14) is connected to a microcontroller (10) by a single conductive track (31 to 34).
[0056] The tracks (31 to 34) connecting the electrodes (11 to 14) to the microcontroller (10) must be as short as possible. Increasing the length of a track means increasing its load. The effect of radiated noise is greater on longer tracks than on shorter tracks. To achieve a higher level of noise immunity against radiated noise, the track length should be as short as possible (typically <200 mm).
[0057] To prevent false touches on the sensor tracks (31 to 34), it is necessary that the track width is between 100 and 500 pm. The sensor track must be routed on the non-touch part of the board and should preferably be connected to the sensor with a through-hole via. This makes the track insensitive to touch.
[0058] The sensor tracks (31 to 34) should not be placed close to other tracks and components, as this can cause charging and interference. Longer tracks will load the sensor and reduce its sensitivity. Sensor noise increases when switching signals are close to the sensor signals.
[0059] The spacing between tracks (31 to 34) and the track (31 to 34) - ground (3) spacing must be at least three times greater than the width of track (31 to 34). For sensor tracks crossing other tracks on another layer, it is advisable to cross the tracks at right angles. This reduces capacitive crosstalk.
[0060] A mass ocean located on the layer under the electrodes (11 to 14), on the opposite surface, is used to prevent false touches and electromagnetic interference (EMI), as well as a mass ocean (3) around the sensors in order to isolate them. These mass oceans can be partially filled to reduce the load capacitance. Indeed, the passive protection increases the RC time constant of the sensor and therefore its acquisition time.
[0061] Grounds close to the touch sensor will cause a reduction in touch sensitivity because the electric field emitted by the electrode will be attracted to the ground layer.
[0062] When the substrate affixed to the electrode (11 to 14) is thicker than the distance separating the electrode and the ground layer, the electrode must be moved as far as possible from the ground plane.
[0063] Additionally, the ground plane can be reduced to 50% or 25% fill, which reduces the sensor load while still providing protection. If the application does not risk accidental touch from the back of the board, the ground plane below the electrodes can be removed. This reduces the load capacitance while still providing isolation of the sensor from other circuit components or EMI.
[0064] Exploitation of signals produced by sensors
[0065] For the management of capacitive touch sensors, the electrodes are connected to the inputs of a capacitive touch microcontroller of the CapTIvate type (trade name). This technology is based on the principle of charge transfer to measure the capacitance of the capacitive button and manages the intrinsic capacitance and mutual capacitance modes. The measurement method is based on charge transfer, its principle is as follows: the sensor capacitance must charge up to a certain potential and discharge into a sampling capacitance. This transfer is repeated a certain number N of times until this capacitance is fully charged. This number N of cycles makes it possible to define the sensor's capacitance. When our finger touches the sensor, the sensor's capacitance increases and therefore, the amount of charge transferred to the sampling capacitance is greater. It will then be charged in fewer cycles N than if there was no finger present. The number of cycles is then interpreted by the system and converted into an abstract measure of the capacitance to be more easily usable at the software level.
[0066] When the system is initialized, a first capacity measurement will be carried out. This measurement will be considered by the system as the reference. When a touch is made, the Cx capacitance will increase; if it exceeds a certain threshold above the reference, the system will consider that a touch has been detected.
[0067] For example, the microcontroller is equipped with a 32-bit ARM CORTEX-M0+ core, clocked at 48 MHz and operating at a supply voltage of 3.3 V. This component is equipped with a PTC peripheral which can control up to 16 intrinsic capacitive sensors. Data processing
[0068] The functionalities of the software library are grouped into three modules:
[0069] a) The acquisition module manages all the basic actions such as the calibration and adjustment of the sensors as well as the launch of the acquisition of the measurement.
[0070] b) The post-process, compatible module makes it possible to determine the state of each sensor (high or low state) from the measurements made by the acquisition module. It also offers various functionalities allowing the sensors to adapt to environmental conditions.
[0071] c) The signal conditioning module provides noise filtration and signal coding to produce frames comprising a sensor identifier and a codification of the sensor state. Example protocol
[0072] The main controller (10) provides the interface between the server (RS485 link) and the touch acknowledgment devices (or optionally the signaling assemblies comprising LED alignments and touch sensor alignments on the same flexible or rigid printed circuit, or on two juxtaposed flexible or rigid printed circuits.
[0073] A controller (10) of type STM32F103 (commercial name) can manage 3 serial links.
[0074] A controller (10) of type STM32H730VBTx (trade name) having 9 serial links (8 for the sections and 1 for RS485 communication with the server) can control 8 strips of sections each having a serial link.
[0075] The support management communication protocol allows the transmission of the events that occur on the section keys (on which the state of a key has changed) to the main controller LC8.
[0076] Decomposition of a frame: When a key is pressed or released, the section sends a frame to the main controller.
[0077] We find two pieces of information in this frame: - Event type: key press or release (Edge Bit field) - Identification of the updated key: Section number (Counter field station) + Button number updated on the section (Button number field)
[0078] A frame is composed of two bytes (16 bits of useful data in total).
[0079] An identifying bit makes it possible to identify whether it is the first byte of the frame (value "0") or the second byte (value "1"). The first byte contains a 6-bit coded value corresponding to the station counter (designating the number of the sensor alignment in a set of chained devices); the second byte contains the number of the sensor in its alignment, coded on 4 bits plus a "flag" bit.
[0080] Time marker management: To be able to process this data relating to support, it is necessary to add time information and thus place the events in temporality. This time management is done on the main controller, that is to say that it is upon reception of a frame that a time marker will be added. The main controller takes into account the travel time of the frame coming from the different devices.
[0081] The server's main controller performs the following processing:
[0082] a) Reception of the frames, triggered by the detection of a signal, and verification of the received packets. This check concerns the 0-1 alternation in the first bit of each byte. If the controller detects that the sequence is not respected, this means that a packet is missing and therefore that the frame is erroneous. In this case the controller deletes the packet from the erroneous frame.
[0083] b) Creation and timestamping of events, by decoding the received frames and using an application code. This processing layer will read the reception buffer and retrieve the information in the frames (button number and event type). As for the button number, we will merge the station counter field and the button number field to obtain a unique identifier for the button across the entire system. Here is the calculation of the button number:
[0084] Button number = ribbon number * 1000 + section number * 9 + button number on the section
[0085] With ribbon number: 0 to 7 Once this information is retrieved, it is enough to associate a timestamp with it to obtain a complete event. This timestamp is defined by the number of ms that have elapsed since the last system reset. It is a 32-bit value that can be retrieved by the function.
[0086] c) Processing of support types, by using the flag indicating an acquisition step, and processing by an application code to characterize the interaction of the human operator
[0087] d) triggering actions associated with human interaction. Application to signage
[0088] For signage applications, the invention consists of installing on a printed circuit forming an elongated strip an alignment of individually controllable associated light-emitting diodes (21 to 24),
[0089] a) either on the same flexible printed circuit,
[0090] b) either on an adjacent printed circuit, acknowledgment zones (11 to 14), each placed in the vicinity of the corresponding light-emitting diode, with a reduced number of wires to facilitate the chaining of the modules.
[0091] These modules are typically coated with a self-adhesive sole to facilitate fixing on a shelf or packaging. The control of the light-emitting diodes (21 to 24) is carried out by a bus (1) by a coded electrical signal for the specific addressing of each of the light-emitting diodes (21 to 24) and the control of its state (on, off, color selection) by the sending of frames by a server (100) connected to the chained modules by a wired or radio link. The acknowledgment zones (21 to 24) are each connected by a single track (31 to 34) formed on the flexible printed circuit (5) to a microcontroller (10) ensuring the reading of the state of the acknowledgment zone, and the coding of the information to transmit it on a bus connected to the server (100), in the example described on the same bus (1) as that used for controlling the LEDs.
[0092] The printed circuit (5) further comprises an electrical track (3) used to power the electronic components, via a voltage regulator circuit (35), and a ground conductor or ground plane (3) also providing a screen to reduce electromagnetic interference. A power supply (30) provides current to the chained modules.
[0093] The acquisition zones can be made up in different ways: contactor, formed for example by a deformable metal sheet capable of ensuring contact with the printed circuit (5), resistive sensor, inductive sensor, infrared sensor, surface acoustic wave (SAW) sensors, etc.
[0094] However, the preferred embodiment implements capacitive sensors described below in more detail, without however limiting the invention to this type of acquisition zone. It is also specified that the architecture described with reference to [Fig.l] is not limiting. LED control
[0095] For example, a module is in the form of a flexible strip approximately 20 mm wide and 30 cm long, chainable up to 15 m and includes 9 LEDs necessary for visual indication as well as 9 acquisition sensors useful for touch detection. The LEDs are for example of the type supplied in the form of a matrix LED strip each integrating a microcontroller and a serial interface in cascade, the reception and decoding of data depend on a single signal line with data redundancy and a transmission speed of up to 800 Kbps. The supply voltage is 12 V, and the transmission is done with two 0-5 V logic levels.
[0096] The server sends signals in the form of frames composed of 24 bits: 8 bits to code red, 8 bits for blue and 8 bits for green. The frames of all the LEDs in the strip are placed one after the other and then sent to the first LED, which will recover the first 24 bits and re-send the entire frame, truncated by these first 24 bits.
[0097] Data redundancy is performed if an LED is found to be defective inside the strip, to prevent the failure of one LED in the strip from causing the failure of all the LEDs in the strip. Indeed, each LED receives the frames for all the following LEDs; if the latter fails, the entire sequence of the strip becomes defective. It is therefore interesting to use a data redundancy signal to overcome this failure. Thus, if an LED receives no data on its DIN, it will recover the data on its BIN, truncate the first 24 bits and analyze the following 24 bits, before retransmitting the frame. Electrostatic Discharge (ESD) Protection
[0098] ESD is a sudden flow of current between two charged objects due to static electricity. Typically, this current is very high and can cause permanent damage to the microcontroller. The main sources of ESD are plug-and-play electronic devices, human contact, etc.
[0099] To best protect the microcontroller, series resistors are added as close as possible to the microcontroller at the PTC configured pins. The value of this resistor must be at least 1kQ and can go up to 1MQ. This also helps reduce noise on the track. However, the higher the resistor value, the longer the electrode charging time will be, which leads to an increase in the capacity measurement time and therefore a longer response time and higher consumption. Linear voltage regulator
[0100] The printed circuit further comprises a linear voltage regulator (35) of type STLQ5033R (trade name) with a voltage input ranging from 2.3 to 12V for an output of 3.3V with a maximum output current of 50mA. Sizing
[0101] According to an exemplary embodiment, the sensors (11 to 14) are spaced 13mm apart and measure 2cm by 0.8cm. Their insulation is 1mm.
[0102] The thickness of the VCC (12V) track (2) is 2mm, which allows a current of 5.36A to flow with a temperature rise of 20°C. This allows 487 LEDs (21 to 24) to be lit simultaneously in maximum lighting (white color and maximum intensity). An LED lit in this way consumes 11mA. The LED tracks are drawn in such a way that they cross perpendicularly the sensor tracks placed on the underside of the card.
[0103] The ground plane (3) is 50% filled. On the edges of the board there is a footprint for soldering both right-angled connectors (male on the left, female on the right), but also wires for connecting profiles together or for connecting to the LC8.
Claims
Claims
1. Touch acquisition device comprising an alignment of touch sensors characterized in that it comprises a printed circuit comprising an alignment of N touch sensors (11 to 14) each connected by a track to a controller (10) delivering on a BUS track (1) of said printed circuit a digital signal as a function of the identifier and the state of the corresponding sensor as well as an identifier of said device, said BUS track (1) being capable of being connected either to a server or to another device to form a chain of touch sensors connected by two wires for power supply and one wire for signal transmission or wireless transmission.
2. Touch acquisition device according to claim 1 characterized in that said sensors (11 to 14) are constituted by conductive electrodes formed on the surface of said printed circuit, each of said conductive electrodes being connected by a conductive track to said microcontroller (10).
3. Touch acquisition device according to claim 1 characterized in that said conductive electrodes are formed by a conductive surface surrounded by an insulating peripheral zone separating it from a conductive ground plane printed on said printed circuit formed on the surface of said printed circuit.
4. Touch acquisition device according to claim 2 characterized in that said conductive electrodes have a surface area of between 50 mm2 and 500 mm2.
5. Touch acquisition device according to claim 2 characterized in that said conductive electrodes are coated with an elastically deformable insulating material.
6. Tactile acquisition device according to claim 2 characterized in that said conductive electrodes form an alignment with a pitch of between 10 and 100 mm, and a space between two consecutive electrodes of between 3 and 10 mm, and in that it further comprises light-emitting diodes (21 to 24), the pitch of said alignment of electrodes being identical to the pitch of said alignment of light-emitting diodes (21 to 24),
7. Touch acquisition device according to claim 2 characterized in that said length of the connecting tracks from the conductive surface to the microcontroller is less than 200 mm.
8. Touch acquisition device according to claim 2 characterized in that said light-emitting diodes are controlled by a common NRZ coded signal.
9. Signaling system comprising a tactile acquisition device according to claim 1 characterized in that it further comprises an alignment of N light-emitting diodes arranged on a printed circuit, each of said light-emitting diodes integrating a controller controlling its state as a function of a coded signal transmitted by a track of said printed circuit.
10. 0 Signaling system according to the preceding claim characterized in that said alignments of sensors and said alignments of light-emitting diodes are produced on a common printed circuit.
11. 1 Signaling system according to the preceding claim characterized in that said sensor alignments and said light-emitting diode alignments are produced on a common flexible printed circuit, with common electrical supply tracks for said sensor alignments and said LED alignments.
12. 12. Signaling system according to claim 9 characterized in that said sensor alignments and said light-emitting diode alignments are produced on two adjacent separate printed circuits.
13. 3 Signaling system according to claim 9, characterized in that said alignment of N light-emitting diodes is associated with an alignment of acknowledgment sensors each arranged near one of said light-emitting diodes, said sensors being associated with at least one controller delivering a signal on one of said tracks of said printed circuit according to the identifier and the state of the corresponding sensor.
14. 4 Signaling system according to claim 9 characterized in that each printed circuit has at its two lateral ends, a connector, male on one side of the alignment of LEDs and / or touch sensors and female on the other side, for the connection of the power supply (2, 3) and data (1) tracks to the power supply (2, 3) and data (1) tracks of a consecutive printed circuit, for the chaining of the elements, or for the connection of the element closest to the server to said server.