Wireless screen

Abstract

Display device (1), arranged for integration into equipment (2) which further comprises a housing and a main circuit (16), the display device comprising: a screen (23), arranged for positioning on the housing; a printed circuit board (22), on which the screen is mounted and on which are mounted: a first communication interface (33), arranged to receive upstream data transmitted by the main circuit via wireless communication; a display component (30), arranged to display the upstream data on the screen; a power supply circuit (31). ABRIDGED FIGURE: Fig. 2

Description

Title of the invention: Wireless screen

[0001] The invention relates to the field of equipment provided with a screen and, in particular but not exclusively, to electricity meters and water meters.

[0002] BACKGROUND OF THE INVENTION

[0003] Most recent electricity meters include an LCD (Liquid Crystal Display) screen positioned on the front of the housing. On some of these meters, "+" and "-" pushbuttons allow you to scroll through the displayed information, and sometimes even to communicate with the meter's motherboard, for example to control the closing of a cut-off device integrated into the meter.

[0004] The integration of the LCD screen into the meter raises a number of issues.

[0005] The LCD display can be mounted on a circuit board, which is then connected to the meter's motherboard.

[0006] The LCD screen circuit board may be soldered onto the motherboard, which causes the following problems.

[0007] When performing maintenance on the LCD screen, it may be necessary to unsolder the LCD screen printed circuit board from the motherboard, which is a relatively complex operation.

[0008] Moreover, it is generally avoided to position components on the motherboard opposite the entire surface of the printed circuit of the LCD screen, because access to these components, which could be made necessary for a maintenance operation, would require unsoldering the printed circuit of the LCD screen. A significant surface area for installing components on the motherboard is therefore lost.

[0009] The LCD screen printed circuit board can also be connected to the motherboard via HE 14 type rigid metal strips.

[0010] The LCD screen circuit board, or the LCD screen itself, can also be connected to the motherboard via ribbon cables.

[0011] These solutions complicate the assembly of the meter in the factory, and present a relatively large footprint (both on the motherboard and between the motherboard and the LCD screen printed circuit). These solutions are also relatively expensive.

[0012] SUBJECT OF THE INVENTION

[0013] The object of the invention is to simplify the assembly of equipment incorporating a screen, to facilitate maintenance operations, to reduce the cost of the equipment, and to limit the size and the impact of the presence of the screen on the installation of components in the equipment. Summary of the invention

[0014] With a view to achieving this aim, a display device is proposed, arranged to be integrated into equipment which further comprises a housing and a main circuit integrated in the housing, the display device comprising: • a screen, arranged to be positioned on the housing; • a printed circuit, on which the screen is mounted and on which are mounted: • a first communication interface, arranged to receive uplink data transmitted by the main circuit via wireless communication; • a display component, arranged to display the uplink data on the screen; • a power supply circuit, arranged to supply power to the display device.

[0015] The display device therefore forms a fully integrated block, which communicates via wireless communication with the main circuit of the equipment in which it is installed.

[0016] This solution is extremely advantageous, because it is no longer necessary to provide a connection requiring contact (wires, connectors, ribbon cables, etc.) between the screen and the main circuit to transmit the data to be displayed to the screen, which resolves the difficulties mentioned earlier. Advantageously, the power supply circuit of the display device comprises a power source (a battery for example), or receives power via a wireless channel, which makes it possible to eliminate any connection requiring contact between the display device and the main circuit.

[0017] A display device is further provided as previously described, in which the first communication interface is also arranged to transmit downlink data to the main circuit via wireless communication, the display device further comprising a second communication interface arranged to produce the downlink data from an interaction with an entity external to the equipment and to transmit said downlink data to the first communication interface.

[0018] Further provided is a display device as previously described, wherein the wireless communication is optical communication.

[0019] A display device as previously described is further provided, wherein the wireless communication is radio frequency communication.

[0020] A display device as previously described is further provided, in which the main circuit may comprise a primary winding and the power supply circuit comprises a secondary winding, the main circuit being able to generating a supply current which induces an induced current in the secondary winding, said induced current being used to power the display device.

[0021] Further provided is a display device as previously described, wherein wireless communication is also implemented via the primary winding and the secondary winding.

[0022] A display device as previously described is further proposed, in which the power supply circuit comprises a battery.

[0023] A display device as previously described is further proposed, in which the power supply circuit comprises a connector of type HE 14.

[0024] A housing cover for an item of equipment is further provided, comprising a display device as previously described.

[0025] We further propose equipment comprising a housing, a main circuit, and a display device as previously described.

[0026] We further propose equipment as previously described, in which the housing comprises a cover to which the printed circuit of the display device is fixed by elastic fitting.

[0027] We further propose equipment as previously described, the equipment being an electric meter or a water meter.

[0028] The invention will be better understood in light of the following description of particular non-limiting embodiments of the invention. Brief description of the drawings

[0029] Reference will be made to the attached drawings, among which:

[0030] [Fig.l] [Fig.l] represents a simplified sectional view of the base, the cover, the motherboard and the display device of the electric meter, according to a plane perpendicular to the front face of the meter;

[0031] [Fig.2] [Fig.2] schematically represents the display device and the card mother according to a first embodiment;

[0032] [Fig.3] [Fig.3] schematically represents the display device and the card mother according to a second embodiment;

[0033] [Fig.4] [Fig.4] schematically represents the display device and the card mother according to a third embodiment;

[0034] [Fig.5] [Fig.5] schematically represents the display device and the card mother according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] With reference to Figures 1 and 2, the display device 1 according to a first embodiment is here integrated into an electric meter 2 which is used to measure the electric energy consumed by an installation 3 and supplied by a network of dis 4. The distribution network can be a single-phase or polyphase network.

[0036] The electric meter 2 comprises a housing 5 (made of plastic for example) comprising a main housing portion, called base 6, and a cover 7. The base 6 comprises a rear face 8 of the housing 5, intended to be applied against a wall and fixed to the wall. The cover 7 comprises an external face 9, which is also the front face of the housing 5, which is visible and accessible by the subscriber or by an operator.

[0037] Here, by “internal” we mean on the inside of the meter 2 when it is assembled, and by “external” we mean on the outside.

[0038] The cover 7, which is fixed to the base 6 when the housing 5 is assembled, is removable and can be removed and moved away from the base 6 by an operator to open the housing 5.

[0039] The cover 7 comprises a rectangular opening 11 formed in its thickness e, which has larger dimensions at the external face 9 of the cover 7 than at the internal face 12. This enlargement of the opening 11 forms a shoulder defining a surface 14 on which is positioned a transparent plate 15 (made for example of glass or transparent plastic) which therefore extends over a portion of the front face 9 of the housing 5.

[0040] The meter 2 comprises a main circuit, which is here an electrical card 16 called a “motherboard”. The motherboard 16 comprises a printed circuit 17 which is positioned close to and parallel to the internal face of the base 6.

[0041] A certain number of components are mounted on the printed circuit 17 of the motherboard 16, including a microcontroller 18 called here “metrology microcontroller” which, in particular, acquires the measurements made by the different sensors of the counter 2 and carries out certain processing on said measurements.

[0042] The meter 2 further incorporates a cut-off device 19. The cut-off device 19 is intended to selectively cut off the current supplied to the installation 3. The cut-off device 19 comprises a switch 20 for each phase of the distribution network 4.

[0043] The cut-off device 19 is controlled by a microcontroller 21 called “application microcontroller”, which is mounted on the motherboard 16.

[0044] The display device 1 comprises a printed circuit 22, separate from that of the motherboard 16, and a screen, in this case an LCD screen 23 which is mounted (here soldered) on the external face of the printed circuit 22.

[0045] The display device 1 is integrated in the meter 2 in the following manner. The edges of the printed circuit 22 are fixed by elastic fitting to the cover 7. The cover 7 thus comprises tabs 24 which extend from the internal face 12 of the cover 7 perpendicular to it, and which are each provided at its free end with a hook 25. A receiving surface 26 is defined on the internal face 12 of the cover 7. The receiving surface 26 extends around the opening 11. The tabs 24 extend on either side of the receiving surface 26. The hooks 25 each comprise a surface 27 inclined towards the internal face 12 of the cover 7 and located on the side of the receiving surface 26.

[0046] When mounting the display device 1, the edges of the printed circuit 22 press and slide against the surfaces 27 of the hooks 25, which move apart slightly to allow the printed circuit 22 to pass, which is positioned parallel to the internal face 12 and against the receiving surface 26. The LCD screen 23 is then positioned in the opening formed in the thickness e of the cover 7, so that its external surface is entirely covered by the transparent plate 15.

[0047] When the meter 2 is assembled, the printed circuit 22 is positioned parallel to the printed circuit 17 of the motherboard 16, at a distance typically between 1 cm and 6 cm from the latter.

[0048] The display device 1 further comprises a display component, in this case a microcontroller 30 called here “LCD microcontroller”, a power supply circuit 31, a first communication interface 33 and a second communication interface 34. All these components are mounted on the printed circuit 22.

[0049] The LCD microcontroller 30 fully controls the LCD screen 23, by activating and deactivating it, by powering it, and by providing it with the data to be displayed in the appropriate format.

[0050] The power supply circuit 31 comprises a battery 35, positioned in a housing fixed on the internal face of the printed circuit 22. The power supply circuit 31, and therefore the battery 35, supplies the entire display device 1. As the LCD screen 23 is switched off most of the time, there is no critical constraint concerning the lifetime of the battery 35.

[0051] The power supply circuit 31 also comprises two capacitors C1, C2, mounted on the LCD microcontroller 30 (on 2 different pins of the microcontroller 30), which make it possible to provide a one-off power supply supplement to ensure the supply of current during current draw peaks by the LCD screen 23. Each of the capacitors C1 and C2 is for example formed by a capacitor having a capacitance value of 1 pF, in parallel with a capacitor having a capacitance value of 68 pF.

[0052] The first communication interface 33 is arranged to receive uplink data transmitted by the motherboard 16 via wireless communication. The wireless communication here is optical communication.

[0053] The first communication interface 33 comprises a light signal receiver, here in this case an infrared photodiode 36.

[0054] The motherboard 16 comprises a light signal transmitter, in this case an infrared LED (light-emitting diode) 38.

[0055] The photodiode 36 and the LED 38 are positioned opposite each other.

[0056] The first communication interface 33 of the display device 1 comprises plus a light signal transmitter, in this case an infrared LED 40.

[0057] The motherboard 16 comprises a light signal receiver, in this case an infrared photodiode 42.

[0058] The LED 40 and the photodiode 42 are positioned opposite each other.

[0059] The first communication interface 33 is therefore also arranged to transmit downstream data to the motherboard 16.

[0060] The counter 1 further comprises an optical guide 43, mounted between the printed circuit 22 of the display device 1 and the printed circuit 17 of the motherboard 16, so as to surround the LEDs 38, 40, the photodiodes 36, 42, and therefore the optical communication channel over its entire length.

[0061] The optical guide 43 has a cylindrical shape and makes it possible to guide and concentrate the light signals between the LEDs 38, 40 and the photodiodes 36, 42.

[0062] The second communication interface 34 is arranged to produce downlink data from an interaction with an entity external to the meter 2, and to transmit said downlink data to the first communication interface 33 (which itself transmits them to the motherboard 16). The external entity is here an individual (subscriber or operator a priori).

[0063] The second communication interface 34 here comprises two push buttons: a “+” button (B+) and a “-” button (B-), which are mounted on the printed circuit 22, which are positioned close to the LCD screen 23, and which can be actuated from outside the meter 2.

[0064] The subscriber or operator, by pressing these buttons, can scroll through the information displayed on the LCD screen 23. The subscriber or operator can also, by making a long press on the B+ button, control the closing of the cut-off device 19.

[0065] The second communication interface 34 therefore transforms these commands into downlink data which are then transmitted to the motherboard 16 via the first communication interface 33, so that the motherboard 16 performs the required actions. These required actions consist in this case of having the LCD screen 23 display the requested information by transmitting it to the display device 1 via the first communication interface 33, or of ordering the closing of the cut-off device 19.

[0066] Wireless communication is therefore a bidirectional full-duplex type communication which uses an infrared physical layer (LED and photodiode in each direction of communication). The communication implements a serial link. The protocol used is for example HDLC (for High-Level Data Link Contract), based on asynchronous HDLC frames (with for example a rate of 9600 bits / s and 8-bit asynchronous characters without parity). The sequence of characters to be transmitted is passed in the payload (sometimes translated as payload, or useful data) of the uplink HDLC frame (from the motherboard 16 to the display device 1) byte by byte in ASCII. In the downlink direction, to close the cut-off device 19, for example, an HDLC frame containing the payload byte 0x01 is sent.

[0067] The display device 1 is therefore a single, fully integrated, energy-autonomous block, which can be mounted and assembled prior to the assembly of the meter 2 and which can have its own reference (Part Nurnbef). It can also be integrated with the cover 7 to form a single block having its own reference.

[0068] Thus, when assembling the meter 2, it is sufficient to fix the display device 1 to the cover 7 (if they are not already integrated into a single block), here by elastic fitting, then to fix the cover 7 to the base 6 of the housing 5. No electrical connection must be made between the display device 1 and the rest of the meter 2 during assembly, which greatly facilitates assembly and significantly reduces the cost of the meter 2. It is also possible to mount components on the surface of the printed circuit 17 of the motherboard 16, which is located in the projection of the surface of the printed circuit 22 of the display device 1, because said surface is directly accessible when the cover 7 is removed from the housing 2.

[0069] With reference to [Fig. 3], in a second embodiment, the display device 101 of the counter 102 no longer comprises the second communication interface 34, and therefore no more push buttons B+, B-. The second communication interface 34, and therefore the push buttons B+, B- are no longer positioned on the printed circuit 122 of the display device 101, but on the printed circuit 117 of the motherboard 116. Here, the push buttons B+, B- are connected to the application microcontroller 21.

[0070] Downstream communication is therefore no longer required (sufficient unidirectional communication), so that the first communication interface 133 of the display device 101 no longer includes the LED 40, and the motherboard 116 no longer includes the photodiode 42.

[0071] With reference to [Fig.4], in a third embodiment, the display device 201 of the counter 202 no longer includes a battery 35.

[0072] This time, the power supply circuit 231 comprises a connector 50, here of the female HE14 type, mounted on the printed circuit 222 of the display device 201.

[0073] The motherboard 216 has an additional connector 51, therefore HE14 male, positioned opposite the connector 50.

[0074] Thus, during assembly of the counter 202, the display device 201 is positioned so that the connector 50 connects to the connector 51. The display device 201 is therefore powered by the motherboard 216 via the connectors 50, 51.

[0075] This embodiment is advantageous compared to the prior art, because the connectors 50, 51 each only have two contacts: Vcc (3.3 V for example) and 0 V. The connectors 50, 51 therefore take up very little space on the printed circuits and in particular on that of the motherboard 216.

[0076] There is therefore indeed a contact connection between the display device 201 and the motherboard 216, but this connection is compact, inexpensive, simple to handle, and does not require a desoldering operation to move the display device 201 (and the cover 7) away from the motherboard 216.

[0077] With reference to [Fig. 5], in a fourth embodiment, the display device 301 of the counter 302 does not include a battery 35 or a connector 50.

[0078] This time, the wireless communication between the display device 301 and the motherboard 316 is a radio frequency communication.

[0079] The first communication interface 333 of the display device 301 comprises a secondary winding 360, formed here by tracks printed on the internal face of the printed circuit 322. The first communication interface 333 also comprises one or more capacitors 361 connected to the secondary winding 360, as well as a transistor 362 connected to a load 363.

[0080] Similarly, the motherboard 316 comprises a primary winding 364, formed here by printed tracks extending on the internal face of the printed circuit 317, and which, advantageously, has the same dimensions and is arranged coaxially with the secondary winding 360. The motherboard 316 also comprises one or more capacitors 366 connected to the primary winding 363, an amplifier 367, as well as a transistor 368 connected to a load 369.

[0081] The inductance values ​​of the windings 360, 364 and the capacitance values ​​of the capacitors 361, 366 are set such that, when the meter 302 is assembled and the windings 360, 364 are positioned opposite each other, the windings 360, 364 and the capacitors 361, 366 form a resonant circuit at a predefined frequency (e.g. 13.56 MHz).

[0082] Wireless communication and power supply of the display device 301 are achieved via the primary winding 364 and the secondary winding 360.

[0083] The amplifier 367 produces a supply current la which flows in the primary winding 364, and which generates a magnetic field which induces an induced current li in the secondary winding 360. The induced current li powers the display device 301.

[0084] Uplink communication is via transistor 368 which connects or disconnects load 369 from primary winding 364 to produce high and low states of the uplink data. This modulates the magnetic field, and therefore the induced current li. This modulation is captured by a demodulation circuit of the first interface of communication 333 (not shown) which then recovers the uplink data. Similarly, the downlink communication is done via transistor 362 which connects or disconnects load 363 from secondary winding 360 and therefore modulates the magnetic field, which modulates the supply current 1a. This modulation is captured by a demodulation circuit of the motherboard 316 (not shown) which then recovers the downlink data. The communication is this time a half-duplex communication.

[0085] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0086] The screen is not necessarily an LCD screen, it can be any type of screen (LED, OLED, etc.).

[0087] The display device could be fixed to the cover in a different way, for example by screwing.

[0088] The different embodiments can be combined. In particular, one could have: - a battery in the display device, associated with any other means of power supply (via connectors, wireless); - wireless communication and wireless power supply using different techniques (e.g. optical for communication and radio frequency for power supply); - uplink and downlink communication in the first communication interface, even without a second communication interface (the LCD microcontroller could, for example, transmit monitoring data to the motherboard); - etc.

[0089] Optical communication does not necessarily use infrared signals. The components used may be different (e.g. phototransistors instead of photodiodes).

[0090] The radio frequency communication may be carried out at one or more frequencies different from that cited herein. The windings may be formed not by printed tracks on the printed circuits of the display device and the motherboard, but by copper wire coils, patch antennas, etc. The radio frequency communication does not necessarily use amplitude modulation.

[0091] The external entity, with which the second communication interface of the display device communicates, is not necessarily an individual. It could be an external device, a data concentrator or a smartphone for example, the second communication interface then comprising in this case means of suitable communications (radio frequencies for example).

[0092] The main circuit is not necessarily a motherboard of a meter (or other), it can be any electrical device arranged to transmit data to be displayed on a screen.

[0093] The equipment incorporating the display device is not necessarily a meter but can be any type of equipment.

Claims

Claims

1. Display device (1; 101; 201; 301), arranged to be integrated into equipment (2; 102; 202; 302) which further comprises a housing (5) and a main circuit (16; 116; 216; 316) integrated into the housing, the display device comprising: • a screen (23), arranged to be positioned on the housing; • a printed circuit (22), on which the screen is mounted and on which are mounted: • a first communication interface (33; 133), arranged to receive uplink data transmitted by the main circuit via wireless communication; • a display component (30), arranged to display the uplink data by the screen; • a power supply circuit (31), arranged to power the display device.

2. A display device according to claim 1, wherein the first communication interface (33) is also arranged to transmit downlink data to the main circuit (16) via wireless communication, the display device further comprising a second communication interface (34) arranged to produce the downlink data from an interaction with an entity external to the equipment and to transmit said downlink data to the first communication interface (33).

3. A display device according to one of the preceding claims, wherein the wireless communication is an optical communication.

4. A display device according to one of claims 1 or 2, wherein the wireless communication is radio frequency communication.

5. A display device according to one of the preceding claims, wherein the main circuit (316) may comprise a primary winding (364) and the power supply circuit comprises a secondary winding (360), the main circuit being able to generate a power supply current (la) which induces an induced current (li) in the secondary winding, said induced current being used to power the display device.

6. A display device according to claims 4 and 5, wherein the

7.

8.

9.

10.

11.

12. wireless communication is also implemented via the primary winding (364) and the secondary winding (360). Display device according to one of the preceding claims, in which the power supply circuit (31) comprises a battery (35). Display device according to one of the preceding claims, in which the power supply circuit (231) comprises a HE14 type connector (50). Cover (7) of a housing (5) of an equipment (2), comprising a display device according to one of the preceding claims. Equipment (2; 102; 202; 302) comprising a housing, a main circuit, and a display device according to one of claims 1 to 8. Equipment according to claim 10, in which the housing comprises a cover to which the printed circuit (22) of the display device (1) is fixed by elastic fitting. Equipment according to one of claims 10 or 11, the equipment being an electric meter or a water meter.

Images