Wireless screen

Abstract

A display device (1) arranged to be integrated in an apparatus (2) further comprising a housing and a main circuit (16), the display device comprising:-a screen (23) arranged to be positioned on said housing; -a printed circuit (22) on which the screen is mounted and on which are mounted: o a first communication interface (33) arranged to receive uplink data transmitted by the main circuit via wireless communication; o a display component (30) arranged to cause the screen to display uplink data; and a power supply circuit (31).

Description

Technical Field

[0001] The present invention relates to the field of devices provided with a screen and particularly, but not exclusively, to electricity and water meters. Background Art

[0002] Most new electricity meters include an LCD (Liquid Crystal Display) screen located on the front face of the housing. On some of these meters, buttons "+" and "-" make it possible to scroll through the displayed information and even sometimes communicate with the main board of the meter, for example to command the closing of a disconnection member integrated in the meter.

[0003] Integrating an LCD screen into an instrument cluster creates a number of problems.

[0004] The LCD may be mounted on a printed circuit which is then connected to the main board of the meter.

[0005] The printed circuit of the LCD screen may be soldered to the main board, which leads to the following problems.

[0006] During the maintenance operation of the LCD screen, it is necessary to desolder the printed circuit of the LCD screen from the main board, which is a relatively complicated operation.

[0007] Furthermore, it is usually avoided to position the components on the mainboard facing the entire surface area of ​​the printed circuit of the LCD screen, since access to these components (which may be necessary for maintenance operations) would require desoldering the printed circuit of the LCD screen. The result is then a loss of a large amount of surface area for mounting components on the mainboard.

[0008] The printed circuit of the LCD screen can also be connected to the mainboard with the help of rigid metal strips of the HE14 type.

[0009] The printed circuit of the LCD screen or even the LCD screen itself can also be connected to the mainboard with the help of a ribbon cable.

[0010] These solutions make it more difficult to assemble the meter in the factory and take up a relatively large amount of space on the main board and between the main board and the printed circuit of the LCD screen. They are also relatively expensive. Summary of the invention

[0011] The purpose of the invention is to simplify the assembly of a device comprising a screen, to facilitate maintenance operations, to reduce the cost of the device and to limit the space required by the screen and the impact of its presence on the installation of components in the device.

[0012] In order to achieve this object, a display device is proposed, which is arranged to be integrated into an apparatus comprising a housing and a main circuit integrated into the housing, the display device comprising:

[0013] - a screen arranged to be positioned on the housing;

[0014] - a printed circuit on which the screen is mounted and on which is mounted:

[0015] o a first communication interface arranged to receive uplink data transmitted by the primary circuit via wireless communication;

[0016] o a display assembly arranged to cause a screen to display uplink data;

[0017] oA power supply circuit arranged to supply power to the display device.

[0018] The display device thus forms a fully integrated block which communicates via wireless communications with the main circuit of the device in which it is installed.

[0019] This solution is extremely advantageous since it is no longer necessary to provide a connection requiring contact between the screen and the main circuit (wires, connectors, ribbon cables, etc.) in order to transmit the data to be displayed to the screen, thus solving the above-mentioned problem. Advantageously, the power supply circuit of the display device comprises a power source (e.g. a battery) or receives power via a wireless channel, making it possible to eliminate any connection requiring contact between the display device and the main circuit.

[0020] In addition, a display device as described above is proposed, wherein the first communication interface is also arranged to transmit downlink data to the main circuit via wireless communication, and the display device also includes a second communication interface, which is arranged to generate downlink data from interaction with an entity outside the device and transmit the downlink data to the first communication interface.

[0021] In addition, there is proposed a display device as described above, wherein the wireless communication is optical communication.

[0022] Furthermore, there is proposed a display device as described above, wherein the wireless communication is radio frequency communication.

[0023] In addition, a display device as described above is provided, wherein the main circuit may include a primary winding, and the power supply circuit includes a secondary winding, the main circuit is capable of generating a power supply current that induces an induced current in the secondary winding, and the induced current is used to power the display device. In addition, a display device as described above is provided, wherein wireless communication is also achieved by means of the primary winding and the secondary winding.

[0024] In addition, there is proposed a display device as described above, wherein the power supply circuit includes a battery.

[0025] In addition, a display device as described above is proposed, wherein the power supply circuit includes a HE14 connector. .

[0026] Furthermore, a cover for a housing of an apparatus is proposed, the apparatus comprising a display device as described above.

[0027] In addition, a device including the housing, the main circuit and the display device as described above is proposed.

[0028] Furthermore, an arrangement as described above is proposed, wherein the housing comprises a cover to which the printed circuit of the display device is attached by elastic interlocking.

[0029] In addition, a device as described above is proposed, wherein the device is an electricity meter or a water meter.

[0030] The invention may be better understood from the following description of certain non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Reference will be made to the accompanying drawings, in which:

[0032] [ Figure 1 ] Figure 1 is a simplified cross-sectional view of the base, cover, main board and display device of an electric meter, together with a plane perpendicular to the front surface of the meter;

[0033] [ Figure 2 ] Figure 2 Schematically shows a display device and a main board according to a first embodiment;

[0034] [ Figure 3 ] Figure 3 schematically shows a display device and a main board according to a second embodiment;

[0035] [ Figure 4 ] Figure 4 schematically shows a display device and a main board according to a third embodiment;

[0036] [ Figure 5 ] Figure 5 A display device and a main board according to a fourth embodiment are schematically shown. DETAILED DESCRIPTION

[0037] See also Figure 1 and 2 , the display device 1 according to the first embodiment is in this case integrated in an electricity meter 2 for measuring the electrical power consumed by an installation 3 and supplied by a distribution network 4. The distribution network may be a single-phase network or a multi-phase network.

[0038] The electricity meter 2 comprises a housing 5 (for example made of plastic material) comprising a main housing part, called base 6, and a cover 7. The base 6 comprises a rear surface 8 of the housing 5, which is intended to rest against and be attached to a wall. The cover 7 comprises an outer surface 9, which is also the front surface of the housing 5 and is visible and accessible to a customer or operator.

[0039] Here, the term "inside" is used to refer to inside the meter 2 when the meter is assembled, and the term "outside" is used to refer to outside.

[0040] The cover 7 attached to the base 6 when the housing 5 is assembled is removable and can be removed and separated from the base 6 by an operator in order to open the housing 5 .

[0041] The cover 7 comprises a rectangular opening 11 formed in its thickness e, which has a greater dimension at the outer surface 9 of the cover 7 than at its inner surface 12. This enlargement of the opening 11 forms a shoulder defining a surface 14 on which a transparent plate 15 (for example made of glass or a transparent plastic material) is positioned, which thus extends over a portion of the front surface 9 of the housing 5.

[0042] The meter 2 comprises a main circuit, in this example an electrical board 16 called main board. The main board 16 comprises a printed circuit 17 located close to the inner surface of the base 6 and parallel to this inner surface.

[0043] Several components are mounted on a printed circuit 17 of the mainboard 16 , including a microcontroller 18 , referred to herein as “metering microcontroller”, which in particular acquires the measurements made by the different sensors of the meter 2 and performs certain processing operations on said measurements.

[0044] The meter 2 also comprises disconnection means 19. The disconnection means 19 are intended to selectively disconnect the current supplied to the installation 3. The disconnection means 19 comprises a switch 20 for each phase of the distribution network 4.

[0045] The cut-off member 19 is controlled by a microcontroller 21 , referred to as an “application microcontroller”, which is mounted on the main board 16 .

[0046] The display device 1 further comprises a printed circuit 22 which is different from the printed circuit of the main board 16 and a screen which is in this case an LCD screen 23 which is mounted (in this case soldered) on the outer surface of the printed circuit 22 .

[0047] The display device 1 is integrated in the meter 2 in the following manner. The edge of the printed circuit 22 is attached to the cover 7 by elastic interlocking. The cover 7 therefore comprises tabs 24 extending perpendicularly to the inner surface 12 of the cover 7 from the inner surface 12 and each of which is provided with a hook 25 at their free end. A receiving surface 26 is defined on the inner surface 12 of the cover 7. The receiving surface 26 extends around the opening 11. These tabs 24 extend on either side of the receiving surface 26. The hooks 25 each comprise a surface 27 which is inclined towards the inner surface 12 of the cover 7 and is located beside the receiving surface 26. When the display device 1 is mounted, the edge of the printed circuit 22 is pressed against the surface 27 of the hook 25 and slides against the surface 27 of the hook 25, which is slightly moved apart to allow the printed circuit 22 to pass, and the surface 27 of the hook 25 is positioned parallel to the inner surface 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 the outer surface of said screen is completely covered by the transparent plate 15 .

[0048] When the meter 2 is assembled, the printed circuit 22 is positioned parallel to the printed circuit 17 of the main board 16 , typically at a distance of between 1 cm and 6 cm from the printed circuit.

[0049] The display device 1 further comprises a display component (in this case a microcontroller 30 , referred to herein as “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 .

[0050] The LCD microcontroller 30 has complete control over the LCD screen 23, turning it on and off, supplying it with power and providing it with data to be displayed in the appropriate format.

[0051] The power supply circuit 31 comprises a battery 35 which is positioned in a housing attached to the inner face of the printed circuit 22. The power supply circuit 31 and therefore the battery 35 supply power to the entire display device 1. Since the LCD screen 23 is turned off most of the time, there are no critical constraints on the life of the battery 35.

[0052] The power supply circuit 31 also includes two capacitors C1, C2, which are mounted on the LCD microcontroller 30 (on two different pins of the microcontroller 30) and make it possible to provide temporary (ad hoc) power supply compensation to ensure the current supply during the current draw peaks of the LCD screen 23. By way of example, each of the capacitors C1 and C2 is formed by a capacitor with a capacitance of 1 μF in parallel with a capacitor with a capacitance of 68 pF. )

[0053] The first communication interface 33 is arranged to receive, via wireless communication, uplink data transmitted by the main board 16. The wireless communication here is optical communication.

[0054] The first communication interface 33 comprises an optical signal receiver, in this case an infrared photodiode 36 .

[0055] Furthermore, the main board 16 comprises an optical signal transmitter, in this case an infrared LED (Light Emitting Diode) 38 .

[0056] The photodiode 36 and the LED 38 are positioned to face each other.

[0057] The first communication interface 33 of the display device 1 further comprises an optical signal transmitter, in this case an infrared LED 40 .

[0058] Furthermore, the main board 16 comprises an optical signal receiver, in this case an infrared photodiode 42 .

[0059] The LED 40 and the photodiode 42 are positioned opposite each other.

[0060] The first communication interface 33 is therefore also arranged to transmit downlink data to the main board 16 .

[0061] The meter 1 also comprises an optical guide 43 mounted between the printed circuit 22 of the display device 1 and the printed circuit 17 of the main board 16 so as to surround the LEDs 38 , 40 , the photodiodes 36 , 42 and the optical communication channel over its entire length.

[0062] The optical guide 43 has a cylindrical shape and makes it possible to guide and concentrate the optical signals between the LEDs 38 , 40 and the photodiodes 36 , 42 .

[0063] The second communication interface 34 is arranged to generate downlink data from interaction with an entity external to the meter 2 and to transmit said downlink data to the first communication interface 33 (which in turn transmits them to the main board 16). Here, the external entity is a person (a priori a customer or operator).

[0064] In this case, the second communication interface 34 comprises two buttons, a “+” button (B+) and a “−” button (B−), which are mounted on the printed circuit 22 , positioned close to the LCD screen 23 and can be actuated from the outside of the meter 2 .

[0065] The user or operator can, by pressing these buttons, scroll through the information displayed on the LCD screen 23. The user or operator can also command closing of the cutting member 19 by pressing and holding the button B+.

[0066] Therefore, the second communication interface 34 converts these commands into downlink data, and then transmits the downlink data to the main board 16 through the first communication interface 33, so that the main board 16 performs the required actions. In this case, these required actions involve causing the LCD screen 23 to display the requested information by transmitting the requested information to the display device 1 via the first communication interface 33, or involve commanding the closing of the cut-off part 19.

[0067] The wireless communication is thus a "full duplex" bidirectional communication using an infrared physical layer (LED and photodiode in each communication direction). The communication implements a serial link. For example, the protocol used is an HDLC (High-Level Data Link Control) based on asynchronous HDLC frames (with a bit rate of, for example, 9600 bits / second and 8-bit asynchronous characters without parity check). The character sequence to be sent is transferred byte by byte with ASC11 in the payload of the upstream HDLC frame (from the main board 16 to the display device 1). In the downstream direction, in order to close the disconnection component 19, for example, an HDLC frame is sent including the payload byte 0x01.

[0068] The display device 1 is thus a fully integrated single block, which is autonomous in terms of energy, can be mounted and assembled before the assembly of the meter 2 and can have its own numbering (part number). It can also be integrated with the cover 7 to form a single block with its own numbering.

[0069] Thus, when assembling the meter 2, it is sufficient in this case to attach the display device 1 to the cover 7 by elastic interlocking (unless they are already integrated in a single piece) and then to attach the cover 7 to the base 6 of the housing 5. No electrical connection is required between the display device 1 and the other parts of the meter 2 during assembly, so the assembly is simpler and the cost of the meter 2 is greatly reduced. It is also possible to mount a plurality of components on the surface of the printed circuit 17 of the main board 16, which are located in projection of the surface of the printed circuit 22 of the display device 1, since said surface is directly accessible when the cover 7 is removed from the housing 2.

[0070] See also Figure 3 In the second embodiment, the display device 101 of the meter 102 no longer comprises the second communication interface 34 and therefore no longer comprises the buttons B+, B-. The second communication interface 34 and therefore the buttons B+, B- are no longer located on the printed circuit 122 of the display device 101, but on the printed circuit 117 of the main board 116. In this case, the buttons B+, B- are connected to the application microcontroller 21.

[0071] Downlink communication is therefore no longer required (unidirectional communication is sufficient), so the first communication interface 133 of the display device 101 no longer comprises the LED 40 , and the main board 116 no longer comprises the photodiode 42 .

[0072] See also Figure 4 In the third embodiment, the display device 201 of the meter 202 no longer includes the battery 35 .

[0073] In this case, the power supply circuit 231 comprises a connector 50 , in this case a female HE14 connector, mounted on the printed circuit 222 of the display device 201 .

[0074] The main board 216 includes a complementary connector 51 (ie, male end HE14 ) positioned facing the connector 50 .

[0075] Thus, when the meter 202 is assembled, the display device 201 is positioned so that the connector 50 is connected to the connector 51. The display device 201 is thus powered by the mainboard 216 through the connectors 50,51.

[0076] This embodiment is advantageous over the prior art because the connectors 50 , 51 each comprise only two contacts: Vcc (eg 3.3 V) and 0 V. The connectors 50 , 51 therefore occupy very little space on a printed circuit, in particular on a printed circuit of the motherboard 216 .

[0077] Thus, a contact connection does exist between the display device 201 and the main board 216, but this connection is compact, cheap, simple to operate, and does not require a desoldering operation to separate the display device 201 (and the cover 7) from the main board 216.

[0078] See also Figure 5 In the fourth embodiment, the display device 302 of the meter 301 does not include the battery 35 or the connector 50 .

[0079] At this time, the wireless communication between the display device 301 and the main board 316 is radio frequency communication.

[0080] The first communication interface 333 of the display device 301 comprises a secondary winding 360, in this case formed by tracks printed on the inner surface of the printed circuit 322. The first communication interface 333 also comprises one or more capacitors 361 connected to the secondary winding 360, and a transistor 362 connected to a load 363.

[0081] Similarly, the main board 316 comprises a primary winding 364, in this case formed by a printed track extending on the inner surface of the printed circuit 317 and advantageously having the same dimensions as the secondary winding 360 and arranged coaxially therewith. The main board 316 also comprises one or more capacitors 366 connected to the primary winding 364, an amplifier 367 and a transistor 368 connected to a load 369.

[0082] The inductance values ​​of windings 360, 364 and the capacitance values ​​of capacitors 361, 366 are defined in such a way that when meter 302 is assembled and windings 360, 366 are positioned facing each other, windings 360, 364 and capacitors 361366 form a resonant circuit at a predetermined frequency (eg, 13.56 MHz).

[0083] Wireless communication and power supply of the display device 301 are performed through the primary winding 364 and the secondary winding 360 .

[0084] The amplifier 367 generates a supply current Ia flowing in the primary winding 364 and generates a magnetic field that induces an induced current Ii in the secondary winding 360. The induced current Ii supplies power to the display device 301.

[0085] Uplink communication is performed by means of transistor 368, which connects or disconnects load 369 to primary winding 364 to produce high and low states of uplink data. This modulates the magnetic field and thereby modulates the induced current Ii. The modulation is picked up by the demodulation circuit (not shown) of the first communication interface 333, and then the uplink data is recovered. Similarly, downlink communication is performed by transistor 362, which connects or disconnects load 363 to secondary winding 360 and thereby modulates the magnetic field, thereby modulating the supply current Ia. This modulation is picked up by the demodulation circuit (not shown) of the mainboard 316, and then the downlink data is recovered. In this case, the communication is half-duplex communication.

[0086] It goes without saying that the invention is not limited to the embodiments described but comprises any variant coming within the ambit of the invention as defined by the claims.

[0087] The screen does not have to be an LCD screen, but can be any type of screen (LED, OLED, etc.).

[0088] The display device may be attached to the cover in different ways, for example by screwing.

[0089] Various embodiments may be combined. In particular, there may be:

[0090] - a battery in the display device, coupled (wirelessly, by means of a connector) to any other power supply;

[0091] - Different technologies for wireless communication and wireless power supply (e.g. optical technologies for communication and radio frequency technologies for power supply);

[0092] - even without the second communication interface, uplink communication and downlink communication in the first communication interface (e.g. LCD microcontroller can send monitoring data to the main board);

[0093] -etc.

[0094] Optical communication does not necessarily use infrared signals. The components used may be different (e.g., phototransistors instead of photodiodes).

[0095] Radio frequency communication may be at one or more frequencies different from those described herein. The windings may be formed not by printed tracks on the printed circuits of the display device and motherboard, but by coils of copper wire, patch antennas, etc. Radio frequency communication does not necessarily use amplitude modulation.

[0096] The external entity with which the second communication interface of the display device communicates is not necessarily a person.

[0097] It may be an external device, a data concentrator or a smartphone, for example, the second communication interface comprising suitable communication means (e.g. radio frequency). The main circuit is not necessarily the mainboard (or similar) of the meter; it may be any electrical device arranged to send data to a screen for display.

[0098] The device including the display device is not necessarily a meter but may be any type of device.

Claims

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

2. The display device according to claim 1, characterized in that The first communication interface (33) is also arranged to transmit downlink data to the main circuit (16) via wireless communication, and the display device also includes a second communication interface (34), which is arranged to generate the downlink data from an interaction with an entity external to the device and transmit the downlink data to the first communication interface (33).

3. The device according to any one of the preceding claims, characterized in that The wireless communication is optical communication.

4. The display device according to claim 1 or any one of claims 1, characterized in that: The wireless communication is radio frequency communication.

5. A display device as claimed in any one of the preceding claims, characterized in that The main circuit (316) can include a primary winding (364), and the power supply circuit includes a secondary winding (360), the main circuit can generate a supply current (Ia) that induces an induced current (Ii) in the secondary winding, and the induced current is used to power the display device.

6. A display device as claimed in claims 4 and 5, characterized in that The wireless communication is also achieved by means of the primary winding (364) and the secondary winding (360).

7. A display device as claimed in any one of the preceding claims, characterized in that The power supply circuit (31) comprises a battery (35).

8. A display device as claimed in any one of the preceding claims, characterized in that The power supply circuit (231) comprises a HE14 connector (50).

9. A cover (7) for a housing (5) of an apparatus (2) comprising a display device as claimed in any one of the preceding claims.

10. An apparatus (2; 102; 202; 302) comprising a housing, a main circuit and a display device as claimed in any one of claims 1 to 8.

11. The device according to claim 10, characterized in that The housing comprises a cover to which the printed circuit board (22) of the display device (1) is attached by elastic interlocking.

12. The device according to any one of claims 10 or 11, characterized in that The device is an electricity meter or a water meter.

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