Patent Publication Number: US-10324421-B2

Title: Optical communication device of a wearable object

Description:
This application claims priority from European Patent Application No.16181952.9 filed on Jul. 29, 2016; the entire disclosure of which is incorporated herein by reference. 
     The present invention relates to a timepiece comprising a case, in which an electronic module supplying at least one item of information is arranged, wherein said at least one item of information is displayed on a dial by display means, characterised in that the electronic module additionally comprises a communication unit having an optical receiving device, wherein said optical receiving device comprises at least one photoelectric receiver arranged to face a first aperture formed on the dial so that an optical signal can be received by said optical receiver. 
     PRIOR ART 
     There is currently a distinction made between two types of watches: mechanical watches that have no electronics and so-called electronic watches that operate with a battery and a microcontroller. Electronic watches have evolved tremendously to increasingly become so-called connected watches. These connected watches are fitted with a communication module using an NFC and/or Bluetooth module that enables the exchange of data with another device such as a mobile telephone (smart phone) or portable computer or electronic tablet. This exchange of data currently allows the transfer of data from a sensor located in the watch to the mobile phone or electronic tablet, these devices having a much superior computing power. This exchange of data also allows data such as notification or messaging to be sent from the telephone to the watch in order to inform the user. 
     These electronic watches can use analogue devices such as hands or discs or electronic screens using LCD, LED or OLED technologies for the display of time information such as the time or the date. The use of hands or discs requires the use of at least one motor and wheel trains so that the adjustment of the time occurs manually, which can cause inaccuracies and time shifts. 
     Another method of communicating is the use of optical technology using a phototransistor to receive an encoded light signal. However, this technology has the disadvantage of requiring apertures in the dial for the passage of light and is subject to risks associated with the outside light environment. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to remedy the disadvantages of the prior art by proposing a device that enables a simple, effective optical communication that is as invisible as possible. 
     For this purpose, the invention relates to a timepiece comprising a case, in which an electronic module supplying at least one item of information is arranged, wherein said at least one item of information is displayed on a dial by display means, characterised in that the electronic module additionally comprises a communication unit having an optical receiving device, wherein said optical receiving device comprises at least one photoelectric receiver arranged to face a first aperture formed on the dial so that an optical signal can be received by said optical receiver, and said optical receiving device additionally comprises an occultation device interposed between the dial and the photoelectric receiver and movably mounted to be able to obstruct or let through the external optical signal. 
     An advantage of this invention is that it allows an optical communication between a wearable object such as a watch and another device without changing the nature of the original design. This then allows such a communication device to be incorporated into existing watches. 
     In a first advantageous embodiment said optical receiving device comprises two photoelectric receivers, each photoelectric receiver facing a first aperture formed on the dial, and said optical receiving device additionally comprises an occultation device interposed between the dial and each photoelectric receiver. 
     In a second advantageous embodiment the occultation device comprises a shutter configured in the form of a circular segment mounted on a shaft at its pointed end, wherein said shaft is driven by a motor so that the shutter can be set in rotation. 
     In a third advantageous embodiment the display means comprise at least one disc, which is rotatably mounted and set in rotation by at least one motor, wherein said disc carries information to be displayed through a window formed on the dial, the disc and the window serving as occultation device and first aperture respectively, and in that said disc additionally has a second aperture arranged to able to be located to face the first aperture and the photoelectric receiver to let through an optical signal. 
     In a fourth advantageous embodiment the disc of the display means has a plurality of positions, in each of which an item of information is located, and the second aperture is a slot located between two positions. 
     In a fifth advantageous embodiment the disc of the display means has a plurality of positions, in each of which an item of information is located, and said disc has an additional position, in which a second aperture is formed. 
     In a sixth advantageous embodiment the disc of the display means has a plurality of positions, in each of which a marking is located, and the second aperture is a slot at least partially merged with a marking. 
     In another advantageous embodiment the disc of the display means has a plurality of positions, in each of which a marking is located, and the second aperture is a slot at least partially merged with a marking. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aims, advantages and characteristics of the invention will become clearer in the following detailed description of at least one embodiment of the invention given solely as a non-restrictive example illustrated by the attached drawings, wherein: 
         FIGS. 1 and 2  schematically show the wearable object according to the invention; 
         FIGS. 3 and 4  schematically show a first embodiment of the wearable object according to the invention; 
         FIG. 5  schematically shows a first practical example of the first embodiment of the wearable object according to the invention; 
         FIGS. 6 to 11  schematically show a second practical example of the first embodiment of the wearable object according to the invention; 
         FIGS. 12 a  and 12 b    schematically show a variant of the first embodiment of the wearable object according to the invention; 
         FIG. 13  schematically shows a second embodiment of the wearable object according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show a watch or timepiece  1  according to the invention. The watch  1  therefore comprises a case  1   a  fitted with a wristband  1   b . Arranged in this case is an electronic module  10 , which comprises a microcontroller  11  supplied with electricity by a supply unit  12  such as a battery, and said microcontroller  11  comprises a time base and memory zones. This microcontroller  11  is used in order to send control signals to display means  13 , and these display means  13  may comprise hands  13 ′ or discs that cooperate with markings of a dial  14 . These display means  13  allow the display of an item of time information such as the time, but may also display the date, the day of the month or the phase of the moon. The microcontroller  11  is also connected to control means  16 , which may be a crown, push buttons or touch-sensitive elements. The electronic module  10  may also comprise a communication unit  15  to receive data, and even at least one sensor  17 . 
     According to the invention the communication unit  15  is configured to enable an optical communication. For this, the communication unit  15  comprises an optical receiving device  150  that allows reception of a light signal. 
     This optical receiving device  150  is advantageously located at the level of the dial  14 . This optical receiving device  150  comprises at least one photoelectric receiver  151 . This photoelectric receiver  151  is generally a phototransistor or photodiode, i.e. a semiconductor component having the ability to detect radiation in the optical range and transform it into an electric signal. In the case of a phototransistor, this is a bipolar transistor, the base of which is sensitive to light radiation. When the base is illuminated, the phototransistor is equivalent to a closed switch between the transmitter and the collector and when the base is not illuminated, it is equivalent to an open switch. 
     According to a first embodiment shown in  FIGS. 3 and 4  the photoelectric receiver  151  is positioned under the dial  14 , this having an aperture referred to as the first aperture  152 . This first aperture  152  allows the light to pass through the dial  14  in order to be received by said photoelectric receiver  151 . However, it is therefore necessary to conceal this first aperture  152  as far as possible so as not to impair the aesthetic appearance of the dial  14 . 
     According to a first embodiment shown in  FIG. 5  the optical receiving device  150  additionally comprises an occultation device  153 . This occultation device  153  consists of a shutter  154  mounted to be rotatable or to allow translational movement. This shutter  154  advantageously allows the phototransistor  151  to be concealed when this is not used. For example, the shutter  154  will be in the form of a circular segment fixed to a shaft  155  at the level of its point in order to be set in rotation by a motor  156  on demand. 
     According to a second embodiment shown in  FIGS. 6 and 7  the occultation device  153  is part of the display means  13 . In fact, these display means  13  may comprise a disc  13 ″, the calendar date disc, for example, to display an item of information via a window in the dial that serves as first aperture  152 . This disc  13 ″ is driven by a motor and comprises information such as the calendar date (day, month) or the phase of the moon. Astutely, this disc  13 ″ comprises an aperture referred to as the second aperture  157 . This second aperture  157  allows a light signal to pass through the dial  14 . For this, the watch is capable of operating in an operating mode, in which data can be received. This mode may be activated automatically or via control means. When this operating mode is activated, the disc is set in rotation so that the second aperture of the disc is located facing the first aperture of the dial. The light signal can thus be received by the photoelectric receiver. 
     In a first practical example of this second embodiment shown in  FIG. 8  the second aperture  157  of the disc  13 ″ may be a slot  157   a . In the case of a calendar date disc, i.e. equipped with regularly distributed markings, this slot  157   a  is located between two positions (2 dates). This slot  157   a  is located in a zone that is invisible when one date or the other is displayed. To establish the communication, the disc  13 ″ is guided so this slot  157   a  is positioned above the photoelectric receiver  151 , i.e. that it is located between two date passages. The slot  157   a  is thus aligned with the window, i.e. the first aperture  152 , and the photoelectric receiver  151 . The optical communication can be performed. In a particular configuration the slot  157   a  will merge into one of the markings to be as invisible as possible, as evident in  FIG. 9 . 
     In a second practical example of this second embodiment the second aperture  157  involves punching an additional position Pi, as shown in  FIGS. 10 and 11 . In fact, in the case of a calendar date disc  13 ″ thirty-one positions Pi are provided, referred to as P 1  to P 31 , one for each day of a month. The aim here is to provide a 32nd position P 32  for the second aperture. This second aperture  157  is thus configured in the form of a cutout inscription  157   b . The cutout of the inscription allows the light to pass through to the photoelectric receiver  151 . The punched inscription appears dark/black like the rest of the traced markings on the disc. 
     In a variant of this second embodiment the 32nd position will simply be a cut made directly in the disc. This cut thus allows the passage of light. 
     It is, of course, conceivable that in the case where the display of the calendar date uses two discs  13 ″, referred to as D 1  and D 2 , partially superposed to display the day of the month, each of the discs  13 ″ is provided with this second aperture  157  as a slot or opening or cut. The discs are then set in rotation so that the openings/slots/cuts provided therein are located to face each other, as shown in  FIGS. 12 a    and  12   b.    
     In a second embodiment the optical receiving device comprises two photoelectric receivers  151 , as shown in  FIG. 13 . The presence of two photoelectric receivers  151  allows information to be received in duplicate and thus allows the received messages to be compared. It is therefore possible to detect an error. Therefore, the dial has two first apertures: one for each photoelectric receiver  151 . Each first aperture of the dial is associated with a second aperture arranged on an occultation device, which may be an information display disc (calendar date, day, phase of the moon) or a movable shutter. 
     For this second embodiment it is possible that the presence of the two photoelectric receivers  151  allows the use of a synchronous data transmission. In fact, such a data transmission uses a clock signal in parallel to clock the transmission of data. This thus requires having two separate receivers to send two separate signals. 
     According to the present invention the occultation device is set in motion after a command is received. This command may be activated via the control means of the timepiece. This latter may comprise push buttons or touch-sensitive keys enabling action on the electronic module to activate functions including a communication function. 
     This activation of the receipt of optical data may be performed by means of a radio signal. In fact, the communication unit may additionally comprise a Bluetooth or NFC type interface. In this case a radio signal sent by a device such as a smart phone or a beacon is received by the timepiece that will then activate the optical reception. 
     Moreover, the timepiece may be compatible with Li-Fi technology. This technology is a wireless communication technology based on the use of visible light ranging between radiation (480 nm wavelength, i.e. 670 THz) (perceived as blue) and radiation (650 nm, i.e. 460 THz) (perceived as red). Whereas Wi-Fi uses a radio portion of the electromagnetic spectrum outside the visible spectrum, Li-Fi uses the visible (optical) portion of the electromagnetic spectrum. The principle of Li-Fi rests on coding and transmitting data via amplitude modulation of the light sources (scintillation imperceptible to the eye) according to a well defined and standardised protocol. 
     It will be understood that various modifications and/or improvements and/or combinations evident to a person skilled in the art can be applied to the different embodiments of the invention outlined above without departing from the framework of the invention defined by the attached claims. 
     In fact, a variant of the different embodiments may be provided, in which the communication unit  15  additionally comprises an optical receiving device  150 , an optical emission device allowing the emission of a light signal. Such a device generally consists of a photodiode capable of generating a light signal following an electrical excitation.