Display device

Abstract

A display apparatus includes: a display that is at least partially transparent, the display configured to generate light to form an image for display to a user positioned in front of the display; and at least one light transmitting and / or light receiving device positioned behind the display, wherein the at least one light transmitting and / or light receiving device is configured to transmit and / or receive light through at least a portion of the display, wherein the at least one light transmitting and / or light receiving device comprises or forms part of an optical wireless communication (OWC) apparatus configured to transmit and / or receive light through at least a portion of the display.

Description

[0001] This application is a divisional application of the Chinese national application corresponding to international application PCT / GB2018 / 050093, filed on 12 January 2018 and entitled “Display device”, (application number: 201880006367.0, entered into the Chinese national phase on 09 July 2019). TECHNICAL FIELD

[0002] The present invention relates to a display device for an electronic device having at least one integrated optoelectronic component, for example, a display device for an electronic device having an integrated optical wireless communication transceiver. BACKGROUND

[0003] Many optoelectronic components can require light reception and / or light transmission to enable their operation. Such components can include, but are not limited to, optical wireless communication (OWC) transceivers, light-based motion detectors, cameras, optical sensors, solar cells, proximity sensors, or flashlights.

[0004] Optoelectronic components that require light reception and / or light transmission to enable their operation can require that the path between the optical detector or transmitter and the external environment is completely unobstructed.

[0005] Visible light captured by the sensor of a camera can require that the path between the captured image and the sensor is substantially unobstructed. Infrared (IR) light emitted and received by a proximity sensor can require that the path between the proximity sensor and the incoming IR radiation is completely unobstructed in order to enable detection. An OWC transmitter can require a completely unobstructed path to successfully emit radiation (e.g., IR light) for uplink (UL) communication. An OWC receiver can require a completely unobstructed path to successfully receive radiation (e.g., visible light radiation) for downlink (DL) communication.

[0006] In many known devices, optoelectronic components are placed at or near the surface of an electronic device (e.g., a mobile phone, a tablet, a laptop, or other computer). For example, optics for a camera, a proximity sensor, an OWC transmitter, or an OWC receiver, or other light receiving or light emitting components can be integrated at the surface of the user device in which these components are embedded. The optoelectronic components can be placed towards the edge of the device, avoiding obstruction to or by other components of the device.

[0007] Figure 1is a schematic illustration of a mobile phone that includes an integrated camera module and an integrated proximity sensor. The front surface of the mobile phone 10 (where the front surface is the surface that is typically viewed by a user) includes a display screen area 12, a first bezel area 14, and a second bezel area 16. Each bezel area 14, 16 includes an area of the front surface of the phone that does not provide a display function. A camera 18 and a proximity sensor 20 are integrated into the first bezel area 14 of the mobile phone 10.

[0008] For example, the display screen area 12 can include a display that includes a liquid crystal (LCD) layer and an array of LEDs positioned behind the LCD layer. The LEDs are configured to provide backlighting for the LCD layer (which does not itself produce light).

[0009] The optics for the camera 18 and the proximity sensor 20 are integrated at the surface of the mobile phone 10. Thus, the camera 18 and the proximity sensor 20 are integrated in a bezel area (the first bezel area 14) on a side of the screen (i.e., outside of the display screen area 12) where there is space available for components of the camera 18 and the proximity sensor 20.

[0010] An OWC module can be integrated into a bezel area of a mobile phone in a similar manner, such that light incident on the mobile phone can be collected by the optical detectors of the OWC module. Light emitted by the optical transmitter of the OWC module can need to be able to escape and radiate from the device according to the requirements of the optical front end designer. The transmitter (TX) and / or receiver (RX) optics of the OWC device can be located at the surface of the bezel similar to the camera 18 and the proximity sensor 20 shown in Figure 1

[0011] The space in the bezel areas 14, 16 can be limited. The limited space in the bezel 14, 16 can place significant restrictions on the size of the OWC module and the size of additional modules that can be placed in the bezel.

[0012] Recent mobile phone designs have had a trend of continually shrinking the size of one or more of the bezel areas, and it is also believed that some designers can want to be able to eliminate the bezel entirely (e.g., by creating a design where the entire front surface of the mobile phone is completely covered by a display screen).

[0013] ​It is known to provide transparent solar cell modules that can be integrated on top of a mobile phone screen so that the mobile phone can still perform its intended use while the solar cell harvests energy. It has been proposed that solar cells can potentially be used as OWC detectors. However, the nature of a transparent solar cell is that most of the light passes through the solar cell and only a small amount of the incident light is harvested. If this were not the case, then the solar cell would not be transparent which can degrade the display image emitted by a display underneath the solar cell. For high speed data rates used in modern wireless communication standards, the solar cell can be too slow which can limit the use of a transparent solar cell as an OWC detector. SUMMARY

[0014] In a first aspect of the application, there is provided a display apparatus comprising: a display that is at least partially transparent; and at least one light transmitting and / or light receiving device located behind the display; wherein the at least one light transmitting and / or light receiving device is configured to transmit and / or receive light through at least a portion of the display. The display can be configured to generate light to form an image for display to a user, e.g. a user located in front of the display. The at least one light transmitting and / or light receiving device can comprise or form part of an optical wireless communication (OWC) apparatus configured to transmit and / or receive light through at least a portion of the display.

[0015] The at least one light transmitting device can be configured to transmit modulated light comprising an uplink data signal to a further OWC device. The OWC apparatus (e.g. a transceiver of the OWC apparatus) can be configured to encode the uplink data signal in the transmitted modulated light. The at least one light receiving device can be configured to receive modulated light comprising a downlink data signal from a further OWC device. The OWC apparatus (e.g. a transceiver of the OWC apparatus) can be configured to decode the received modulated light to obtain the downlink data signal encoded in the received modulated light.

[0016] The display can comprise one or more layers. For example, the display can comprise a plurality of sub-layers that together provide the display function. The at least one light receiving device can comprise at least one photodetector.

[0017] The at least partial transparency of the display enables light to pass through at least a portion of the display. Thus, the light transmitting and / or light receiving device can be placed behind the display layer rather than in an area external to the display (e.g. a bezel area). In some cases, by placing one or more light transmitting and / or light receiving devices behind the display rather than in the bezel, it can be possible to reduce the size of the bezel or it can be possible to remove the bezel entirely.

[0018] In some cases, the light transmitting and / or light receiving devices can be made larger than if they were placed in the bezel. The light transmitting and / or light receiving devices can be placed on an area that includes a majority of the area of the display screen.

[0019] Multiple light transmitting and / or light receiving devices can be located on a single layer behind the display screen. Different light transmitting and / or light receiving devices can be located on different layers behind the display screen. In some cases, the light transmitting and / or light receiving devices can be separate modules. These separate modules can be located adjacent to each other behind the display screen. The separate modules can be located behind the display screen such that there is no clear demarcation of the layer to which the separate modules belong.

[0020] The light transmitting and / or light receiving devices can be concealed by the presence of the display. An image can be displayed on the display, which can block a user’s view of the light transmitting and / or light receiving devices behind the display.

[0021] The display can be substantially planar. Positioning at least one light transmitting and / or light receiving device behind the display can include positioning the at least one light transmitting and / or light receiving device on a side of the display plane opposite a side from which a user views the display.

[0022] The at least partially transparent display can be at least partially transparent to at least one of visible light, ultraviolet light, and infrared light.

[0023] The transparency of the display can be independent of an image displayed on the display. The degree of transparency of the display can vary independent of image content, e.g., image color and / or intensity.

[0024] The display can include a plurality of at least partially transparent display elements.

[0025] The plurality of at least partially transparent display elements can each provide a respective pixel of an image displayed by the display. The plurality of display elements can include display elements of different colors, e.g., red display elements, green display elements, and blue display elements. The display screen can also include a plurality of non-transparent display elements.

[0026] The at least partially transparent display element can include a transparent organic light emitting diode (TOLED).

[0027] The at least partially transparent display element includes at least one of a micro-LED, a quantum dot LED, or a light field display element.

[0028] The at least one light transmitting and / or light receiving device can be independent of the at least partially transparent display element. The at least one light transmitting and / or light receiving device can operate at a different wavelength and / or modulation speed and / or power output than the at least partially transparent display element.

[0029] The at least one light transmitting and / or light receiving device can include at least one electro-optical device, optionally an array of electro-optical devices. The at least one light transmitting and / or light receiving device can include at least one of: at least one transceiver; at least one LED, optionally at least one micro-LED, quantum dot LED, or light field display element.

[0030] The at least one light transmitting and / or light receiving device can include or form part of an optical wireless communication (OWC) apparatus, e.g., an OWC transceiver, OWC receiver, OWC transmitter. The at least one light transmitting and / or light receiving device can include a light-based motion detector, camera, solar cell, proximity sensor, flash, light level detector.

[0031] Light transmitted and / or received by the at least one light transmitting and / or light receiving device can include at least one of visible light, infrared light, ultraviolet light.

[0032] Light transmitted by the at least one light transmitting and / or light receiving device can have the same wavelength as light generated by the display. For example, the display can be configured to generate light in the visible spectrum, and the at least one light transmitting and / or light receiving device can also be configured to transmit visible light. Transmitting light by the at least one light transmitting and / or light receiving device can be independent of the display generating light.

[0033] Light transmitted by the at least one light transmitting and / or light receiving device can be different from light generated by the display. For example, the display can generate visible light, and the at least one light transmitting and / or light receiving device can transmit infrared light. The transmitted infrared light can not be felt by a user. As another example, the display can generate visible light, and the at least one light transmitting and / or light receiving device can transmit non-visible light.

[0034] By transmitting light using the at least one light transmitting and / or light receiving device that is not part of the display, the transmitted light can be independent of an image displayed on the screen. Parameters of the light transmitted by the at least one light transmitting and / or light receiving device can not be affected by changes in the image displayed on the screen, e.g., changes in image color or intensity. For example, the light transmitted by the at least one light transmitting and / or light receiving device can have a wavelength and / or intensity that does not vary with image content.

[0035] LEDs that are part of the display can in some cases not be suitable for communication. Using separate light transmitting devices can allow communication to be achieved while also not impacting the display.

[0036] Light transmitted and / or received by the OWC transmitter and / or receiver can include at least one of visible light, ultraviolet light, infrared light. Light transmitted by the OWC transmitter can include infrared light. Light received by the OWC receiver can include visible light.

[0037] The OWC transmitter and / or receiver can include a light fidelity (LiFi) transmitter and / or receiver. Light transmitted by the OWC transmitter can include a LiFi uplink signal. Light received by the OWC receiver can include a LiFi downlink signal.

[0038] The OWC transmitter and / or receiver can be configured to modulate light transmitted through at least a portion of the display to encode data in the transmitted light, e.g., according to a modulation scheme. The OWC transmitter and / or receiver can be configured to demodulate light received through at least a portion of the display to obtain data encoded in the received light, e.g., data encoded according to the modulation scheme or said modulation scheme.

[0039] The modulation scheme can include at least one of on-off keying (OOK), phase-shift keying (PSK), M-ary pulse amplitude modulation (M-PAM), M-ary quadrature amplitude modulation (M-QAM), or orthogonal frequency-division multiplexing (OFDM).

[0040] The at least one light transmitting and / or light receiving device can include at least one solar cell.

[0041] The at least one solar cell can be configured to at least partially power the display device. The at least one solar cell can be configured to at least partially power an electronic device in which the display device is contained. The at least one solar cell can be configured to charge a battery.

[0042] The at least one solar cell can be configured to detect a light signal. The light signal can include a communication signal. The at least one solar cell can be configured to detect a light level. The light level can include an ambient light level.

[0043] By placing the solar cells behind the display, the solar cells can be made larger than if they were placed in a non-display area, e.g., in a bezel. One or more solar cells can occupy a large portion of the display area, e.g., greater than 20% of the display area, optionally greater than 50% of the display area, further optionally greater than 80% of the display area. The increased area of the solar cells can result in increased captured solar energy. The battery life of the electronic device can be extended.

[0044] The at least one light receiving and / or light transmitting device can include at least one of a light-based motion detector, a camera, a proximity sensor, a flash, a light level detector.

[0045] The at least one light receiving and / or light transmitting device can include at least one large area photodetector. The at least one large area photodetector can occupy an area of at least 10 mm 2 , optionally at least 20 mm 2 , further optionally at least 50 mm 2 , further optionally at least 100 mm 2 , further optionally at least 200 mm 2 . The at least one large area photodetector can occupy at least 10% of the display area, optionally at least 20% of the display area, further optionally at least 50% of the display area.

[0046] The at least one light receiving and / or light transmitting device can include a plurality of photodetectors.

[0047] The use of a large area photodetector and / or a plurality of photodetectors can allow for capturing light over a larger area than some existing systems. In some cases, the use of a large area photodetector and / or a plurality of photodetectors can reduce or eliminate optical components associated with the at least one light receiving and / or light transmitting device.

[0048] The at least one light transmitting and / or light receiving device can be positioned such that there are no additional optical components between the at least one light transmitting and / or light receiving device and the display.

[0049] The at least one light receiving and / or light transmitting device can include a plurality of transmitters. The transmitters can be dispersed across the display area.

[0050] The at least one light receiving and / or light transmitting device can include at least one large area transmitter. The at least one large area transmitter can occupy an area of at least 10 mm 2 , optionally at least 20 mm 2 , further optionally at least 50 mm 2 , further optionally at least 100 mm2 further optionally at least 200 mm 2 The at least one large-area transmitter can occupy at least 10% of the display area, optionally at least 20% of the display area, further optionally at least 50% of the display area.

[0051] Using a diffuse and / or large-area transmitter can distribute the radiated light (e.g. radiated infrared light) over a larger area. Distributing the radiated light over a larger area can allow to mitigate the restrictions related to eye safety. For example, a higher total amount of light can be radiated compared to the case where the light is radiated from a smaller transmitter or a smaller number of transmitters.

[0052] The display apparatus can further comprise a module for processing a signal representing light received by the at least one light transmitting and / or light receiving device.

[0053] The module for processing (e.g. a processor, software and / or hardware arrangement) can be configured to process the signal representing light received by the at least one light transmitting and / or light receiving device to identify, compensate and / or at least partially remove a component of the signal representing light emitted by at least a portion of the display.

[0054] At least a portion of the display can emit light backwards. At least a portion of the display can emit light towards the light transmitting and / or light receiving device as well as towards the user. The processor can distinguish between light received through the display (which can comprise the desired signal) and light that has been emitted by the display (which can comprise an unwanted interference). The processor can process light received by any light transmitting and / or light receiving device having at least one light sensitive element, e.g. a communication receiver, a camera sensor or a proximity sensor.

[0055] The processing of the signal can be based on at least one of: a wavelength of the signal; a modulation frequency of the signal. Since the interference changes slowly with respect to the speed of the communication system, the interference can be estimated and can be eliminated or reduced by digital processing.

[0056] The processing of the signal can comprise filtering the signal by wavelength. The processing of the signal can comprise filtering the signal by modulation frequency. The light transmitting and / or light receiving device can comprise an OWC device configured to receive a modulated optical signal, e.g. a baseband modulated signal modulated at a modulation frequency between 1 Hz and 100 GHz, optionally between 1 MHz and 100 GHz, optionally between 100 kHz and 1 PHz. For the processor, the light emitted by the display can appear as a low-frequency interference signal added to the received OWC signal. For example, an image displayed on the display can be displayed with a refresh rate between 30 Hz and 200 Hz.

[0057] The display device can be configured to at least partially compensate for the optical effect of the display. For example, the display device can comprise a module for at least partially compensating for the optical effect caused by the display.

[0058] The optical effect of the display can be a change in the propagation profile of light passing through the display. The optical effect of the display can comprise a change in at least one parameter of light transmitted and / or received through at least a portion of the display. The at least one parameter can comprise at least one of the following: a propagation profile parameter, a wavelength, a polarization parameter, a direction, an aberration parameter, a dispersion parameter, a refraction parameter, a diffraction parameter.

[0059] The display device can comprise at least one optical component configured to compensate for the optical effect of the display. The compensation for the optical effect of the display can comprise changing, by the at least one optical component of the display, a value of at least one parameter of light transmitted and / or received by the at least one light transmitting and / or light receiving device.

[0060] For example, the at least one optical component can comprise at least one lens. As another example, the at least one optical component can comprise at least one of the following: a lens array, a microlens array, a liquid crystal display, a polarizer.

[0061] The at least one optical component can comprise one or more filters. For example, the one or more filters can comprise at least one of the following: an absorption filter; an interference filter; a Fabry-Perot filter; a dichroic filter; a bandpass filter; a tunable filter; a plasmonic filter.

[0062] The compensation for the optical effect of the display can comprise signal processing of light transmitted and / or received by the at least one light transmitting and / or light receiving device performed by a processor of the display device. The signal processing can comprise digital signal processing. The signal processing can comprise analog signal processing.

[0063] The compensation for the optical effect of the display can allow the at least one light transmitting and / or light receiving device to perform as if the display was not present or almost as if the display was not present. As a result of the compensation, the transmission or reception of signals can not be substantially affected by the presence of the display in front of the at least one light transmitting and / or light receiving device.

[0064] The display apparatus can be configured to change at least one property of light emitted by at least a portion of the display, and / or change operation of the display during a time period in which the at least one light transmitting and / or light receiving device transmits and / or receives light through at least a portion of the display. The at least one property can comprise intensity. The change in the at least one property of light can comprise at least one of: reducing the intensity of light emitted by at least a portion of the display, and / or switching off at least a portion of the display. The display apparatus can be configured to switch off at least a portion of the display during a time period in which the at least one light transmitting and / or light receiving device receives light through at least a portion of the display.

[0065] Changing the intensity of light emitted by at least a portion of the display while light is being received through the display can prevent light emitted backwards from the display from affecting light received through the display by the at least one light transmitting and / or light receiving device. In some cases, switching off at least a portion of the screen can remove light originating from the display more efficiently than using signal processing to remove such light. The display apparatus can be configured such that at least a portion of the display is switched off or reduced in intensity for only a short time period. For example, the time period can be between 0.001 seconds and 1 second, optionally between 0.001 seconds and 0.1 seconds, further optionally between 0.01 seconds and 0.1 seconds.

[0066] The change in intensity of at least a portion of the display can be synchronised with modulation of the signal being transmitted or received.

[0067] The at least one light transmitting and / or light receiving device can comprise a sensor element of a camera. The time period can comprise a time period in which the camera is capturing an image.

[0068] By switching off at least a portion of the display during which the camera is capturing an image, an image can be acquired without the need to remove light originating from the display by signal processing. The received light can comprise less interference than if the display were switched on during image capture.

[0069] The at least one light transmitting and / or light receiving device and the plurality of display elements can be configured such that light from the plurality of display elements does not saturate the at least one light transmitting and / or light receiving device.

[0070] The at least one light transmitting and / or light receiving device can be configured to receive light through the display and light originating from the display without also saturating.

[0071] The display apparatus can further comprise an at least partially transparent cover layer positioned in front of the display. The display apparatus can further comprise a capacitive layer positioned in front of the display. The display apparatus can further comprise a backplane layer on which the at least one light transmitting and / or light receiving device is mounted.

[0072] The display can be part of an integrated display screen. The at least one light transmitting and / or light receiving device can be located behind the integrated display screen. The integrated display screen can comprise at least one of: an at least partially transparent cover layer, a capacitive layer, a backplane layer. The integrated display screen can be encapsulated in an encapsulant that does not contain the at least one light transmitting and / or light receiving device.

[0073] Positioning the at least one light transmitting and / or light receiving device behind the integrated display screen can conceal the at least one light transmitting and / or light receiving device behind the integrated display screen so that they are not visible to a user.

[0074] Using an at least partially transparent display screen can allow the at least one light transmitting and / or light receiving device to be manufactured separately from the display screen and then placed behind the display screen at an assembly stage.

[0075] The at least one light transmitting and / or light receiving device can comprise a plurality of different light transmitting and / or light receiving devices.

[0076] Several different types of device can be integrated behind a single display. For example, an OWC transceiver, a proximity sensor and a solar cell can be integrated into a single device. By integrating several light transmitting and / or light receiving devices into a display area, non-display areas (e.g. bezel areas) can be reduced or eliminated.

[0077] In a second aspect of the application, which can be provided independently, there is provided a method of operating a display apparatus comprising an at least partially transparent display and at least one light transmitting and / or light receiving device located behind the display, the method comprising: transmitting and / or receiving light by the at least one light transmitting and / or light receiving device through at least a portion of the display, thereby providing optical wireless communication (OWC), for example using modulated light. The method can comprise displaying an image by the display, for example to a user located in front of the display.

[0078] In another aspect of the application, which can be provided independently, there is provided a display apparatus comprising an optical wireless communication (OWC) apparatus and a display, the display comprising an array of elements, the array of elements comprising:

[0079] a plurality of display elements comprising red elements, green elements and blue elements, the plurality of display elements being configured to display an image to a user; and

[0080] a plurality of light transmitting elements configured to transmit modulated light comprising a data signal (e.g. an uplink data signal) to a further OWC device, wherein the OWC apparatus is configured to encode the data signal in the transmitted modulated light; and / or

[0081] a plurality of light receiving elements configured to receive modulated light comprising a data signal (e.g. a downlink data signal) from a further OWC device, wherein the OWC apparatus is configured to decode the received modulated light, thereby obtaining the data signal encoded in the received modulated light;

[0082] wherein at least one of a) or b):

[0083] a) the light transmitting and / or light receiving elements are distributed in the display in groups of one or more light transmitting and / or light receiving elements, wherein one or more of said groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting and / or light receiving element, at least one red element and at least one green element and at least one blue element; or

[0084] b) the light transmitting and / or light receiving elements are arranged in one or more rows or one or more columns within or at the edge of the display.

[0085] In another aspect of the application, which can be provided independently, there is provided a display apparatus comprising a display comprising an array of elements comprising: a plurality of display elements configured to display an image to a user; and a plurality of light transmitting and / or light receiving elements; wherein the light transmitting and / or light receiving elements: are distributed in the display in groups of one or more light transmitting and / or light receiving elements, wherein one or more of said groups are at least partially surrounded by display elements; or are arranged in one or more rows or one or more columns within or at the edge of the display.

[0086] By having the light transmitting and / or light receiving elements interspersed between the display elements, the light transmitting and / or light receiving elements can be integrated into the display area, even if the display elements are not transparent.

[0087] The plurality of light transmitting and / or light receiving elements can comprise a plurality of photodiodes and / or a plurality of LEDs.

[0088] The plurality of light transmitting and / or light receiving elements can comprise at least one of: an avalanche photodiode (APD), a single-photon avalanche photodiode (SPAD), a photomultiplier tube, a solar cell, a photodiode operated in solar cell mode (forward biased).

[0089] The plurality of light transmitting and / or light receiving elements can comprise at least one of: an LED, a laser diode.

[0090] The array can comprise a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting and / or light receiving element and a plurality of display elements.

[0091] The light transmitting and / or light receiving elements can be distributed in the display in the form of one or more groups of light transmitting and / or light receiving elements, wherein one or more of said groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting and / or light receiving element, at least one red element and at least one green element and at least one blue element

[0092] The plurality of light transmitting elements can be configured to transmit modulated light comprising an uplink data signal to a further OWC device, wherein the OWC transceiver is configured to encode the uplink data signal in the transmitted modulated light. The plurality of light receiving elements can be configured to receive modulated light comprising a downlink data signal from the further OWC device, wherein the OWC transceiver is configured to decode the received modulated light to obtain the downlink data signal encoded in the received modulated light.

[0093] The modulation frequency of the transmitted modulated light can be between 100 KHz and 1 PHz. The modulation frequency of the received modulated light can be between 100 KHz and 1 PHz.

[0094] The modulation frequency of the transmitted modulated light can be between 1 MHz and 100 GHz. The modulation frequency of the received modulated light can be between 1 MHz and 100 GHz.

[0095] The transmitted modulated light can have a wavelength different from the wavelength of the visible light emitted by the display elements. The transmitted modulated light can be non-visible light. The transmitted modulated light can be infrared light.

[0096] Each light transmitting element can have a different output power than each display element.

[0097] The light receiving elements can be arranged in more than one light receiving area, such that each light receiving area is configured to receive light having a different wavelength.

[0098] The display apparatus can comprise a signal collection circuit for each light receiving area, the signal collection circuit being configured to collect detection signals from each light receiving element in the light receiving area, and further configured to synchronize the collection of detection signals over the light receiving area.

[0099] The modulation scheme used to encode the transmitted modulated light and / or the modulation scheme used to decode the received modulated light can comprise at least one of: on-off keying (OOK), phase shift keying (PSK), M-ary pulse amplitude modulation (M-PAM), M-ary quadrature amplitude modulation (M-QAM) or orthogonal frequency division multiplexing (OFDM).

[0100] The plurality of light receiving elements can comprise a plurality of photodiodes, and the plurality of light transmitting elements can comprise a plurality of LEDs and / or laser diodes.

[0101] The display can comprise one or more layers. For example, the display can comprise a plurality of sub-layers that together provide a display function.

[0102] The display can comprise a plurality of at least partially transparent display elements.

[0103] The at least partially transparent display elements can comprise transparent organic light emitting diodes (TOLEDs).

[0104] The at least partially transparent display elements can comprise at least one of: micro-LEDs, quantum dot LEDs, or light field display elements.

[0105] The display apparatus can further comprise a plurality of non-transparent display elements.

[0106] The array of elements can further comprise a plurality of optical front-end circuit elements.

[0107] Each unit cell can comprise at least one optical front-end circuit element. At least one of the optical front-end circuit elements can be arranged in one or more rows or one or more columns within or at an edge of the display.

[0108] At least one of the optical front-end circuit elements can comprise: an amplification circuit element, a buffer circuit element, or a multiplexing circuit element.

[0109] At least some of the display elements can be at least partially transparent. The display apparatus can further comprise at least one further light transmitting and / or light receiving device located behind the display. The at least one further light transmitting and / or light receiving device can be configured to transmit and / or receive light through at least a portion of the display.

[0110] The red elements, the green elements, and the blue elements can be configured to transmit modulated light comprising uplink data signals to a further OWC device.

[0111] The plurality of light transmitting elements and the plurality of light receiving elements can comprise at least one solar cell.

[0112] The at least one solar cell can be configured to at least partially power the display apparatus. The at least one solar cell can be configured to at least partially power an electronic device in which the display apparatus is contained. The at least one solar cell can be configured to charge at least one battery.

[0113] The at least one solar cell can be configured to detect a light signal. For example, the light signal can comprise a communication signal. The at least one solar cell can be configured to detect a light level. For example, the light level can comprise an ambient light level.

[0114] The display apparatus can further comprise a module for processing a signal representative of light received by the at least one light receiving device to identify, compensate and / or at least partially remove a component of the signal representative of light emitted by at least a portion of the display.

[0115] The display apparatus can comprise a module for at least partially compensating for optical effects caused by the display. The module for at least partially compensating for optical effects caused by the display can comprise at least one optical component configured to compensate for optical effects of the display.

[0116] The at least one optical component can comprise at least one of: a lens; a lens array; a microlens array; a liquid crystal display; a polarizer.

[0117] The at least one optical component can comprise one or more filters. For example, the at least one optical component can comprise at least one of: an absorption filter; an interference filter; a Fabry-Perot filter; a dichroic filter; a bandpass filter; a tunable filter; a plasmonic filter.

[0118] The compensation for the optical effects of the display can comprise at least one of: a) changing, by at least one optical component of the display, a value of at least one parameter of light transmitted and / or received by the at least one light transmitting and / or light receiving device; b) performing, by a processor of the display apparatus, signal processing of light transmitted and / or received by the at least one light transmitting and / or light receiving device, for example, wherein the signal processing comprises analog or digital signal processing.

[0119] The display apparatus can be configured to change at least one property of light emitted by at least a portion of the display. The display apparatus can be configured to change operation of the display during a time period in which the at least one light transmitting device transmits light through at least a portion of the display. The display apparatus can be configured to change operation of the display during a time period in which the at least one light receiving device receives light through at least a portion of the display.

[0120] The display apparatus can be configured such that at least a portion of the display is turned off or the intensity of at least a portion of the display is reduced for only a short time period. The display apparatus can be configured such that at least a portion of the display is turned off or the intensity of at least a portion of the display is reduced in synchrony with the modulation of the signal being transmitted or received for only a short time period. The time period can be between 0.001 seconds and 1 second. The time period can be between 0.001 seconds and 0.1 seconds. The time period can be between 0.01 seconds and 0.1 seconds.

[0121] The light transmitting device can be concealed by the presence of the display. The light receiving device can be concealed by the presence of the display.

[0122] An electronic device can be provided comprising a display apparatus as claimed or described herein. An electronic device comprising a display apparatus according to the first or third aspect can be provided. The electronic device can comprise at least one of a mobile phone, a tablet, a computer, a laptop. The electronic device can comprise at least one of an automotive display, an aviation cockpit display, a television, a financial transaction terminal, an industrial control panel.

[0123] In a further aspect which can be provided independently, there is provided a method of providing optical wireless communication (OWC), comprising:

[0124] providing a plurality of display elements comprising red elements, green elements and blue elements, the plurality of display elements being configured to display an image to a user; and

[0125] providing a plurality of light transmitting elements configured to transmit modulated light comprising a data signal (e.g. an uplink data signal) to a further OWC device, wherein the OWC apparatus is configured to encode the data signal in the transmitted modulated light; and / or

[0126] providing a plurality of light receiving elements configured to receive modulated light comprising a data signal (e.g. a downlink data signal) from a further OWC device, wherein the OWC apparatus is configured to decode the received modulated light to obtain the data signal encoded in the received modulated light;

[0127] wherein at least one of a) or b):

[0128] c) the light transmitting and / or light receiving elements are distributed in the display in one or more groups of light transmitting and / or light receiving elements, wherein one or more of said groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting and / or light receiving element, at least one red element and at least one green element and at least one blue element; or

[0129] d) the light transmitting and / or light receiving elements are arranged in one or more rows or one or more columns within or at the edge of the display.

[0130] There can also be provided apparatus or methods substantially as herein described with reference to the accompanying drawings.

[0131] Any feature in one aspect of the application can be applied to other aspects of the application, in any appropriate combination. For example, features of the first aspect can be applied to features of the third aspect, and vice versa. For example, device features can be applied to method features, and vice versa. BRIEF DESCRIPTION OF DRAWINGS

[0132] Embodiments of the application will now be described, by way of non-limiting example only, and with reference to the accompanying drawings in which:

[0133] Figure 1 is a schematic diagram of a mobile phone;

[0134] Figure 2 is a schematic diagram of an integrated LiFi support screen using a transparent organic light emitting diode (TOLED) display matrix according to an embodiment;

[0135] Figure 3 is a schematic diagram of LiFi communication between a mobile device and an access point;

[0136] Figure 4 is a schematic diagram of an integrated LiFi module employing TOLED display cloaking according to an embodiment;

[0137] Figure 5 is a schematic diagram of an RGB display matrix with integrated photodetector and IR LED according to an embodiment;

[0138] Figure 6 is a schematic diagram of an RGB display matrix with integrated photodetector and IR LED according to an embodiment;

[0139] Figures 7(a) and 7(b) show schematic diagrams of pixel structures for displays with integrated OWC transmitters and receivers;

[0140] Figure 8 is a schematic diagram of a micro-LED array;

[0141] Figure 9 is a schematic diagram of a multi-wavelength micro-LED array; and

[0142] Figure 10 is a schematic diagram of a structured addressable array of micro-LEDs. DETAILED DESCRIPTION

[0143] Figure 2is a schematic of a LiFi-enabled screen 30 according to an embodiment. The LiFi-enabled screen 30 can be located in the display screen area of a mobile phone or another device. For example, the LiFi-enabled screen can be used in another mobile computing device, such as a tablet or laptop, or can be used in a desktop computer. The LiFi-enabled screen 30 can be included in any device with a display screen, for example, included in a home appliance or point-of-sale device. The LiFi-enabled screen 30 can be referred to as a display apparatus.

[0144] The LiFi-enabled screen 30 includes a plurality of substantially planar layers. Figure 2 The layers are shown in exploded view as viewed from the side. The layers are represented so that the layer closest to the front surface of the mobile phone is on top of Figure 2 Although these layers are planar and rectangular in this embodiment, in other embodiments, the layers can have any suitable shape.

[0145] In an embodiment of Figure 2 The layers of the LiFi-enabled screen 30 include a cover layer 32, a capacitive layer 34, a display layer 36, and a backplane 38 in an embodiment.

[0146] The cover layer 32 is located at the front surface of the mobile phone, is substantially transparent, and is configured to protect components of the mobile phone. In this embodiment, the cover layer 32 is a protective glass layer 32. In other embodiments, any suitable material can be used.

[0147] In this embodiment, the capacitive layer 34 is a capacitive circuit plane 34 located directly behind the cover glass 32 and can be used to provide touch screen functionality.

[0148] The display layer 36 is located directly behind the capacitive layer 36 and includes a transparent organic light emitting device (TOLED) matrix. The TOLED matrix forms a display that is configured to generate light, in turn forming an image. The TOLED matrix is an array of red, blue, and green TOLEDs, which can also be referred to as display elements or pixels. Each TOLED is substantially transparent to visible light and can also be substantially transparent to infrared light. The TOLEDs can emit light both backward into the mobile phone and forward toward the user.

[0149] TOLEDs have achieved commercialization over the past 5 years, and different electronics companies have begun to offer fully transparent or near fully transparent displays that employ TOLED technology. The distinction between TOLEDs and other types of OLEDs or LEDs is that the materials used to construct TOLEDs are almost completely transparent. A transparent LED display matrix can be constructed using TOLEDs. TOLED technology can be used in transparent display devices and display window products.

[0150] In other embodiments, the display layer can be formed of any material that is at least partially transparent. The display layer can be formed using any technique capable of constructing a transparent display layer.

[0151] In some embodiments, the display layer includes an array of any suitable red display elements, green display elements, and blue display elements, where each display element is at least partially transparent. In some embodiments, the display layer includes some transparent display elements and some non-transparent display elements. For example, transparent red LEDs can be used in combination with non-transparent blue LEDs. The display layer can include multiple sub-layers.

[0152] A backplane layer 38 is positioned directly behind the TOLED matrix 36. A plurality of electro-optical devices are mounted on an upper surface of the backplane layer 38. In the present embodiment, the electro-optical devices include an IR LED 40 and a plurality of photodiodes 42. The IR LED 40 and the plurality of photodiodes 42 are coupled to an OWC transceiver 52 (not shown in FIG. 1). In the present embodiment, the TOLEDs can emit light in two directions, such that some of the light from the TOLEDs is incident on the photodiodes 42. Accordingly, the photodiodes 42 are configured such that light from the TOLEDs does not saturate them. Figure 2

[0153] Although the screen 30 includes the cover layer 32, the capacitive layer 34, the display layer 36, and the backplane layer 38 in the present embodiment, in other embodiments, additional layers can be included. One or more layers of the present embodiment can be omitted. The layers can be placed in a different order. In some embodiments, the circuitry that drives the display layer 36 is on a different layer than the display layer 36 itself. For example, the driving circuitry can be on or behind the backplane layer 38. Figure 2

[0154] The wiring of the electro-optical devices and / or the wiring of other components can be performed using any suitable techniques, means, and materials, e.g., using established techniques, means, and materials of the display manufacturing art.

[0155] In some embodiments, the screen 30 further includes at least one optical filter and / or optical amplifier positioned on top of the photodiodes 42. The at least one optical filter and / or optical amplifier can be positioned directly in front of the photodiodes 42, or between or in front of any layers that are in front of the photodiodes 42. The optical filter and / or optical amplifier can be positioned in any order.

[0156] ​​Some principles of optical wireless communication are now described. A transmitter apparatus is configured to transmit a wireless optical signal over an optical communication channel to a receiver apparatus, wherein information is encoded in the wireless optical signal. The optical communication channel can be a free-space communication channel. The optical communication channel has a characteristic optical wavelength. The channel can be established and / or operated by transmission and / or reception of uplink and / or downlink signals.

[0157] A free-space communication channel includes transmission of optical signals through air, space, vacuum, a liquid such as water, and the like. Free-space communication can not include communication through solid materials.

[0158] Transmitters and receivers can be provided on different devices. One type of device used is an access point. An access point can provide access to another network. Another type of device is a station. Stations can be portable or fixed. Examples of stations include personal computers, desktops, laptops, and smart devices, including mobile devices, without any limitation. Portable stations can be powered by their own battery resources.

[0159] An access point can provide data transmission to and / or from a wired network or a Wi-Fi tm (Wireless Fidelity) or other wireless network and / or other optical wireless communication network (optionally a LiFi network).

[0160] A transmitter apparatus includes a light emitting diode (LED), laser, or other suitable light source, and associated drive circuitry for driving the LED or laser to produce an optical signal. The associated drive circuitry includes a digital-to-analogue converter configured to provide a modulated signal of the frequency characteristic of the optical light communication signal. Another processor provided as part of the transmitter apparatus or associated with the transmitter apparatus modulates data onto the drive current, and the drive circuitry provides this drive current to the LED or laser. The LED or laser then produces an output modulated optical wireless communication signal carrying the data.

[0161] A receiver apparatus includes a photodiode or other suitable light detector, with associated circuitry for conditioning any received signal. The photodiode converts received light into an electronic signal, which is subsequently conditioned by the conditioning circuitry. Conditioning can include one or more filtering steps; amplification of the weak electrical signal; equalisation of the received signal and conversion of the analogue signal to a digital signal using an analogue-to-digital converter. The digital signal can then be provided to a further processor (provided as part of the receiver apparatus or associated with the receiver apparatus) to be demodulated, thereby extracting the communication data. Reference Figure 4 An example of a typical receiver apparatus is described in more detail, in which the conditioning circuitry and further processor correspond to an optical front-end module and baseband processor resources.

[0162] Any suitable modulation scheme can be used, for example, in some embodiments an orthogonal frequency division multiplexing (OFDM) modulation scheme is used, and demodulation is in accordance with the OFDM modulation scheme. In some embodiments, other modulation schemes can be used. The optical wireless communication transmitter and receiver can together be provided as a transceiver.

[0163] Figure 3 is a schematic diagram of a mobile phone 50 in which the LiFi support screen 30 shown in Figure 2 The mobile phone 50 also includes an OWC transceiver 52 located behind the display screen 30 (this positioning is shown by the dashed OWC). The OWC transceiver includes a processor 54. The mobile phone also includes other processors that are not part of the OWC transceiver 52. For example, the mobile phone includes a processor configured to process data and drive display of images on the display screen 30.

[0164] The OWC transceiver can form part of an OWC apparatus included in the display device, which can include other components to provide OWC transmission or detection in accordance with known OWC techniques, for example, any suitable arrangement of one or more of digital to analogue converters and / or analogue to digital converters, amplifiers, filter adjustable gain / attenuation components, LED drive circuitry (not shown).

[0165] In this embodiment, the OWC transceiver 52 is a LiFi transceiver configured to receive data from and transmit data to other LiFi devices using modulated light. The OWC transceiver 52 can be considered to act as a station.

[0166] The method of wirelessly transmitting data using light by modulation of the light can be referred to as optical wireless communication (OWC). LiFi (Light Fidelity) is a form of OWC, in some cases OWC can be considered to be analogous to Wi-Fi in radio frequency communications for at least some applications. However, there are also significant technical differences between LiFi and Wi-Fi. Any suitable LiFi protocol can be used, for example, any protocol that is compliant with a suitable standard.

[0167] Figure 3A LiFi access point (AP) 56 is also shown. The AP 56 is configured to receive data from and transmit data to other devices using modulated light. For example, the AP 56 is configured to receive data from and transmit data to the mobile phone 50. The AP 56 comprises a plurality of components, which are not shown for clarity, but can include, for example, analog-to-digital and digital-to-analog converters, driver circuitry, amplifier circuitry, and processing circuitry. The AP 56 also comprises at least one light source and at least one light sensor.

[0168] An embodiment in which the mobile phone 50, which includes the screen 30, uses LiFi to communicate with the AP 56 will now be described. However, in other embodiments, the mobile phone 50 can use optical wireless communication to communicate with any suitable device. In some embodiments, the mobile phone 50 can communicate with multiple devices simultaneously or near-simultaneously. In some further embodiments, the OWC transceiver 52 is replaced with an OWC receiver without a transmitter, and the mobile phone 50 is configured to receive but not transmit OWC signals.

[0169] In use, an image is displayed to a user on the display layer 36. The image can comprise, for example, a user interface of the mobile phone, a web browser, or content (e.g. text content or video content) that the user is viewing. In some cases, the image can be a simple image, for example, an image comprising a single color, a limited range of colors, or a logo. In the present embodiment, the refresh rate at which the image is displayed to the user is 60 Hz (60 frames per second). In other embodiments, the refresh rate can be any suitable rate, for example, between 30 Hz and 200 Hz.

[0170] The AP 56 receives input data (e.g. Ethernet data). A processor of the AP 56 encodes the input data using on-off keying. In other embodiments, any suitable modulation scheme can be used. Driver circuitry of the AP 56 drives the visible light source (which, in the present embodiment, comprises at least one LED) of the AP 56, thereby transmitting the encoded data by modulation of the light source intensity. In this way, the modulated light from the AP 56 is used to transmit a downlink data signal using modulated visible light.

[0171] A portion of the light transmitted by the AP 56 is incident on the front face of the screen 30. The direction of incidence of the light on the screen 30 is shown by arrow 44 in Figure 2 Figure 3 In the embodiment shown, the light is incident at an angle normal to the plane of the screen. In other embodiments, the light can be incident on the front face of the screen from any suitable angle.

[0172] ​Light incident on the screen 30 passes through the protective glass layer 32, the capacitive circuit plane 34, and the display layer 36. Some of the light incident on the screen can be lost due to reflection or absorption as the light passes through the protective glass layer 32, the capacitive circuit plane 34, and the TOLED matrix layer 36. However, in the present embodiment, most of the light incident on the screen 30 passes through the TOLED matrix layer 36 to the backplane layer 38. At least a portion of the light incident on the screen 30 is received by the photodiode 42. In some embodiments, the light received by the photodiode 42 is filtered by at least one optical filter and / or amplified by at least one optical amplifier. The photodiode also receives some light emitted by the TOLEDs of the display layer 36.

[0173] The light received by the photodiode 42 is converted into an electrical signal and passed to the processor 54 of the OWC transceiver 52. The processor 54 processes the electrical signal to obtain the downlink data signal transmitted by the AP 56.

[0174] The processor 54 is configured to process the electrical signal to distinguish between light emitted from the TOLEDs and light received from the AP 56. Since the TOLEDs can emit light in both directions, light emitted from the TOLED display elements of the display layer 36 can reach the photodiode 42 along with light received from the AP 56. In the present embodiment, the light from the display layer 36 is a low frequency interference signal for the OWC transceiver 52. The frequency spectrum of the interference signal is around the refresh rate of 60 Hz, which is much lower than the modulation frequency of the modulated visible light. The processor 54 of the OWC transceiver 52 removes the light originating from the display layer 36 by using signal processing techniques. In other embodiments, any suitable method can be used to distinguish between light emitted from the display layer 36 and light received through the display layer. For example, the light can be filtered by wavelength, or the undesired low frequency signal can be electrically filtered in the analog electronics part of the receiver system.

[0175] In the present embodiment, the propagation profile of the light received by the photodiode 42 is changed due to the TOLED matrix passing through the display layer 36. (In other embodiments, the propagation profile can be changed by passing through the cover layer 32, the capacitive layer 34, or any other layer in front of the photodiode 42). The change in the propagation profile can include a change in the frequency, direction, or polarization of the light. The change in the propagation profile can include aberrations, dispersion, refraction, or diffraction. The change in the propagation profile can cause distortion in the communication coverage.

[0176] The processor 54 is configured to compensate for the variation in the propagation profile using digital signal processing techniques. In other embodiments, the optics of the photodiode 40 can be configured to at least partially correct for the variation in the propagation profile. For example, at least one optical component (e.g., at least one lens) can be used to compensate for the variation in the propagation profile.

[0177] The processor 54 demodulates the received signal to obtain a downlink data signal transmitted by the AP 56.

[0178] In addition to receiving downlink data from the AP 56 using modulated visible light, the OWC transceiver 52 is configured to drive the IR LED 40 to transmit an uplink data signal using modulated infrared light. The OWC transceiver encodes the uplink data using a suitable modulation scheme and drives the IR LED 40 to transmit the encoded uplink data by modulating the IR light emitted by the IR LED 40.

[0179] The IR LED 40 is independent of the TOLEDs used to form images on the display layer 36. In the present embodiment, the IR LED 40 operates at a different frequency than the TOLEDs of the display layer 36.

[0180] Infrared light from the IR LED 40 is emitted through the TOLED matrix display layer 36. For example, the infrared light from the IR LED 40 can travel in a direction opposite to the direction of the arrow 44. The infrared light passes through the display layer 36, the capacitive layer 34, and the cover layer 32, and exits the screen 30. The uplink data signal can be emitted while an image is displayed on the display layer 36. The light from the IR LED 40 is received by the optical detector of the AP 56 and processed by the AP 56 to obtain the uplink data signal by demodulating the IR light emitted by the IR LED 40.

[0181] Using infrared light for the uplink can avoid producing bright visible light when transmitting the uplink data, e.g., bright visible light that can shine on a user's face.

[0182] Although a single AP 56 and mobile device 30 are described above, in other embodiments, the mobile device 30 can transmit signals to and / or receive signals from multiple APs or other computing devices. An AP can transmit signals to and / or receive signals from multiple mobile devices 30 or other computing devices.

[0183] Because the optical transceiver 52 is integrated behind the transparent display matrix, it becomes less conspicuous from the user's perspective. Using the transparent display matrix provides the OWC transceiver 52 with the radiation required for successful uplink communication. Figure 3 The completely unobstructed path of the IR light in the embodiments, and the radiation required for successfully receiving downlink communication. Figure 3 The visible light in the embodiment has a completely unobstructed path.

[0184] also, Figure 2 and Figure 3 The technology used in the embodiments allows for the integration of additional electronic components that operate by means of light into the mobile phone 50 or any other device. Such components may include, for example, light-based motion detectors, cameras, optical sensors, solar cells, proximity sensors, or flashlights. Components integrated into the mobile phone 50 or other electronic device may include any device that needs to emit or receive light. This component may be any device that emits and / or receives light of a wavelength, with the display screen being at least partially transparent to that wavelength of light.

[0185] In embodiments, any suitable light transmitting and / or light receiving OWC device may be located behind display layer 36, for example, mounted on back panel 38. For example, the light transmitting and / or light receiving device may be an optical wireless communication (OWC) transceiver, OWC receiver, OWC transmitter, light-based motion detector, camera, solar cell, proximity sensor, or flash. In some embodiments, more than one type of light transmitting and / or light receiving device may be located behind a single display layer 36. For example, different devices may be located behind different areas of display layer 36.

[0186] Optical transmitting and / or optical receiving devices may include any suitable photodetector, such as a photodiode, avalanche photodiode (APD), single-photon avalanche photodiode (SPAD), photomultiplier tube, solar cell, photodiode operating in solar cell mode (forward bias), vertical-cavity surface-emitting laser (VCSEL), silicon photomultiplier tube (SiPM), and multi-pixel photon counter (MPPC). Optical transmitting and / or optical receiving devices may include any suitable light source, such as an LED or laser diode.

[0187] Light incident on the TOLED matrix of display layer 36 passes through the LEDs (excluding any light lost due to reflection and absorption as light passes through different materials) and reaches the optical detector or optical detector optics below the TOLED matrix. Any light receiving device can be used as the optical detector. The light receiving device may or may not include a photodiode.

[0188] Light from any light emitting devices located behind the display layer 36 (e.g., light from an IR light of a LiFi transmitter or from an IR light of a proximity sensor) can pass through the matrix of TOLEDs of the display layer 36 and be emitted outward from the device. Changes in the propagation profile of the received or transmitted light can be corrected by corresponding adjustments in the optics of the emitter / detector and / or by digital signal processing techniques. The received data can be processed using any suitable processor, which can or can not be part of the OWC transceiver. In some embodiments, multiple processors of the mobile device 50 can be used to process data received by the light receiving device.

[0189] The light transmitting device located behind the display layer can be independent of the light sources (e.g., TOLEDs of the display layer) whose light is used to form an image to be displayed. The light sources used to form the display image can be different from the light sources used for communication (e.g., for OWC communication).

[0190] In one embodiment, the sensor elements of the camera (e.g., CCD or CMOS elements) are located on the backplate surface 38. The sensor elements receive light that passes through the display layer 36 and use this light to form an image.

[0191] Changes in the propagation profile of the light that passes through the display layer 36 can cause distortions in the image captured by the imaging camera. Such changes can be corrected by at least one optical component and / or by signal processing in a processor. The processor can or can not be part of the camera. In one embodiment, the signal processing of the processor is also used to eliminate the effects of any light emitted by the TOLEDs backward and received by the sensor elements of the camera.

[0192] In another embodiment, the processor is configured to turn off the TOLEDs (e.g., TOLEDs located in front of the sensor elements) that can affect the camera module for a short period of time while the camera takes a photo. For example, a portion or all of the display layer can be turned off for 1 / 30th of a second or 1 / 60th of a second. In some embodiments, the period of time during which at least a portion of the display layer is turned off can be between 0.001 seconds and 1 second, e.g., depending on the acquisition time of the camera. In other embodiments, some or all of the display elements can be turned off or their intensity can be reduced for any period of time during which any suitable device located behind the display layer receives and / or transmits light. In some embodiments, the turning on and off (or intensity reduction) of the display screen can be synchronized with a pulsed signal, e.g., with a LiFi pulse. The turning on and off (or intensity reduction) of the display screen can be synchronized with the modulation of the light transmitted by the device behind the display layer.

[0193] In one embodiment, IR LEDs and photodiodes mounted on the backplane 38 are used as proximity detectors. IR light emitted from the IR LEDs passes through the layers 36, 34, and 32 and is emitted from the screen 30, for example, in a direction substantially perpendicular to the plane of the screen 30. Some of the IR light is reflected from objects located in front of the screen 30. The reflected IR light passes through the layers 32, 34, and 36 into the screen 30 and is detected by the photodiodes. The photodiodes convert the reflected IR light into electrical signals. A mobile device that integrates the screen 30 includes a processor configured to use the signals from the photodiodes representing the reflected LED light to determine the proximity of the object. In some embodiments, the optical wireless communication transceiver is configured to act as a proximity detector.

[0194] In another embodiment, a solar cell is located on the backplane surface 38. For example, the solar cell can include a plurality of photodiodes. The solar cell can be configured to receive visible, infrared, and / or ultraviolet light that passes through the display layers. The solar cell is configured to convert the received light into electrical power for powering the mobile device. In some embodiments, the solar cell is used as an optical wireless communication detector and / or a proximity sensor detector. In some embodiments, the solar cell is configured to detect a light level, for example, an ambient light level.

[0195] By positioning light transmitting and / or light receiving devices behind the display layers, the entire mobile device display area can be utilized to place optoelectronic components, for example, optoelectronic components suitable for OWC, optical sensing, or solar power generation. In the electronic devices described above with reference to Figure 2 and Figure 3 The design of the electronic devices described above with reference to FIGS. 1-4 enables the OWC transceiver 52 to be integrated when a transparent display matrix 36 is employed. Additionally, other optoelectronic components can be integrated using the techniques described above, including, but not limited to, light-based motion detectors, cameras, optical sensors, solar cells, proximity sensors, or flashlights.

[0196] One commercial example can be an integrated camera module and proximity sensor on a mobile phone that can be integrated behind the display matrix in the display area using the techniques described above, rather than in a non-display area such as a bezel. In the case of using a transparent display, the visible light captured by the camera sensor can have a completely unobstructed path between the captured image and the sensor itself, and the infrared light emitted and received by the proximity sensor can have a completely unobstructed path between the sensor and the incoming IR radiation for detection.

[0197] In some cases, components can be made less conspicuous (regardless of the size of the components) by placing them behind the display.

[0198] Due to the trend of shrinking the bezel of mobile device screens, benefits can be realized related to the ability to use the limited space for other optical components. In some cases, by positioning the light transmitting and / or light receiving devices behind the display layer instead of in areas outside of the display area of the mobile device, the bezel of the mobile device can be completely removed.

[0199] In some cases, integrating solar cells into a mobile device (e.g., by placing the solar cells behind the display layer) can significantly increase the battery life of the mobile device. In some embodiments, the entire screen area can be used for integration of solar cells (e.g., high efficiency solar cells). The amount of power that can be captured by the solar cells can be determined by the size of the solar cells.

[0200] In some embodiments, due to the larger area available behind the display layer, when positioning photodetectors behind the display layer, large area photodetectors and / or multiple photodetectors can be used. When one or more photodetectors are not confined to the bezel, larger photodetectors or a greater number of photodetectors can be used.

[0201] In some embodiments, the use of large area photodetectors and / or multiple photodetectors can significantly reduce or eliminate any receiver and / or transmitter optics. In some systems, receiver and / or transmitter optics can be located in front of the receiver and / or transmitter in order to collect more light. When the active area of one or more photodetectors is large enough, then in some cases, sufficient light can be captured without the use of these optics, or the optics used can be reduced.

[0202] In some embodiments, positioning the transmitter behind the display layer enables the use of a diffuse and / or large area transmitter. For example, the transmitter can occupy a larger area when placed behind the display layer than when placed in the bezel. In some embodiments, multiple transmitters are placed at various locations of the display area. In some embodiments, one or more large area transmitters occupy a significant portion of the display area, e.g., 10% of the display area.

[0203] The use of diffuse and / or large area transmitters can reduce restrictions due to eye safety. If a single small light source is used, then eye safety regulations can set limits on the amount of light that can be emitted from the light source. For example, the level of infrared light emitted can be limited to prevent eye damage. When the active area of one or more transmitters is large, then the radiant light (e.g., the radiant infrared light) is distributed over a larger area, which can relax the eye safety restrictions. For example, a higher total amount of light can be emitted when distributed over the entire display area than when emitted from a single small light source.

[0204] In Figure 2 embodiments, the IR LEDs 40 and photodiodes 42 are integrated into the backplane of the LiFi-enabled screen 30. In other embodiments, any light transmitting and / or light emitting devices can be positioned on the backplane 38. In further embodiments, any suitable light transmitting and / or light receiving devices can be located in any suitable position behind the display layer. For example, different devices can be located behind different portions of the display layer. In some embodiments, the screen includes multiple layers behind the display layer, in place of or in addition to a backplane, and light transmitting and / or light receiving devices can be located on any of these multiple layers.

[0205] By using light transmitting devices separate from the light sources forming the display, the device can be adapted for both display and communication (e.g., OWC communication). In some cases, the screen LEDs (e.g., TOLEDs) forming the display can have a relatively low modulation speed and a relatively low power output. In some cases, the screen LEDs can not be suitable for communication, or can only be suitable for short distance communication.

[0206] If the screen LEDs are used for communication, they can be very bright in order to provide high data rates at the distance used for communication (e.g., at the actual distance suitable for LiFi type of connection). Using infrared light for uplink communication can avoid the situation where bright light is shining into the user's face.

[0207] In Figure 2 embodiments, the electro-optical device is integrated in the screen 30, which can be installed as a single unit into a mobile phone. In another embodiment, as shown in Figure 4 the display apparatus includes a transparent display screen 60, which is already a complete and fully operable transparent display, and an optical sensor and / or communication device integrated behind the transparent TOLED display screen 60.

[0208] The transparent display screen 60 can include a cover layer, a capacitive layer, a backplane, and / or other layers. The transparent display screen 60 is packaged as if the optical sensor and / or communication device were not integrated into the display package. The display screen 60 can also include a connector configured to connect the display screen to other components of the mobile phone. In Figure 4 embodiments, the optical sensor and / or communication module are not packaged as part of the display screen 60, but are placed below the display screen 60.

[0209] In Figure 4In the illustrated embodiment, the optical sensor is a photodiode 66 and the optical communication device is an IR LED 64. The photodiode 66 and the IR LED 64 are mounted on another layer 62 that is not part of the integrated display screen 60. The photodiode 66 and the IR LED 64 can be packaged in a separate package from the package of the display screen 60. In other embodiments, any light transmitting and / or light receiving device can be located behind the integrated display screen 60. The light transmitting and / or light receiving device can or can not require a separate package.

[0210] In Figure 4 embodiments, a screen 60 that can display any image or color can be used to conceal the underlying optical sensor module 66. Concealment of the device placed behind the screen 60 can facilitate more aesthetically pleasing integration of the device into a larger electronic device or into the surrounding environment. The screen 60 can hide the photodetector and / or emitter. The hiding of the photodetector and / or emitter can or can not be for aesthetic reasons.

[0211] Placing the light transmitting and / or light receiving device behind a separate, complete transparent screen can enable the screen to be manufactured separately from the light transmitting and / or light receiving device.

[0212] In Figures 2 to 4 embodiments, TOLED technology is used to solve the problem of integrating optical detectors and emitters in electronic devices that employ displays.

[0213] Figure 5 is an illustration of another embodiment in which the detectors and emitters used in optical wireless communication are integrated into the display matrix of a screen using a different integration method. Figure 5 Embodiments of

[0214] In Figure 5 embodiments, a display layer that includes a display matrix is used to present images to a user. The display layer can be located behind a protective glass layer and a capacitive circuit layer, for example, similar to that shown in Figure 2 . Figure 5 A front view of a portion of the display matrix, for example, as viewed by a user in a direction perpendicular to the plane of the display layer, is shown. The layout of the portion of the display matrix shown in Figure 5 may be repeated across the rest of the display layer.

[0215] The display matrix includes a plurality of display elements, which can also be referred to as pixels. In Figure 5In embodiments, the display elements are OLEDs. In other embodiments, any suitable display element can be used, for example, TOLEDs. In some embodiments, the display elements can be back light LEDs for an LCD screen. The plurality of display elements includes a plurality of red display elements 72, a plurality of green display elements 74, and a plurality of blue display elements 76. In Figure 5 In the embodiment shown, the red display elements 72 are represented by vertically striped squares, the green display elements 74 are represented by horizontally striped squares, and the blue display elements 76 are represented by diagonally striped squares.

[0216] Positioned between the display elements are a plurality of photodiodes 78 and a plurality of IR LEDs 80. In Figure 5 In the embodiment shown, the photodiodes 78 are represented by black squares and the IR LEDs 80 are represented by white squares.

[0217] Figure 5 The portion of the display layer shown in FIG. 3 includes a four-fold repetition of a unit cell, the unit cell including a square of four elements by four elements. The constituent elements of the unit cell are a mix of the display elements 72, 74, 76, the photodiodes 78, and the IR LEDs 80.

[0218] Beginning at the upper left of the unit cell, the first row includes, in left-to-right order, a red display element 72, a green display element 74, another red display element 72, and another green display element 74. The second row includes a blue display element 76, a photodiode 78, another blue display element 76, and another photodiode 78. The third row is the same as the first row. The fourth row includes a blue display element 76, a photodiode 78, another blue display element 76, and an IR LED 80.

[0219] The photodiodes 78 and LEDs 80 are interspersed among the display elements 72, 74, 76 such that each photodiode 78 or LED 80 is surrounded by display elements 72, 74, 76.

[0220] In other embodiments, if an RGB display includes a red LED, a green LED, and a blue LED in a repeating pixel configuration, a fourth IR LED or sensor (e.g., photodiode) can be integrated as part of the pixel configuration.

[0221] In further embodiments, the photodiodes and / or LEDs are arranged in one or more rows or one or more columns. In such embodiments, instead of each photodiode 78 or LED 80 being surrounded by a display element 72, 74, 76, each photodiode 78 or LED 80 can be adjacent to at least one other photodiode 78 or LED 80. In some embodiments, one or more rows or one or more columns of photodiodes and / or LEDs are placed along one or more edges of the array of display elements 72, 74, 76. In some embodiments, one or more rows or one or more columns of photodiodes 78 and / or LEDs 80 are placed within the array of display elements 72, 74, 76. For example, a row of photodiodes 78 and / or LEDs 80 can be placed between two rows of display elements 72, 74, 76.

[0222] Although Figure 5 Examples are shown in which the photodiodes 78 and LEDs 80 have similar dimensions to the display elements 72, 74, 76, in other embodiments, any relative dimensions of photodiodes, LEDs, or display elements can be used. Any suitable light transmitting and / or light receiving devices can be used in place of or in addition to photodiodes and / or LEDs.

[0223] Any suitable photodetector can be used in place of or in addition to photodiodes, such as avalanche photodiodes (APDs), single-photon avalanche photodiodes (SPADs), photomultiplier tubes, solar cells, photodiodes operated in solar cell mode (forward biased), vertical cavity surface emitting lasers (VCSELs), silicon photomultipliers (SiPMs), and multi-pixel photon counters (MPPCs). Any suitable light emitter (e.g., laser diodes) can be used in place of or in addition to LEDs.

[0224] By integrating light transmitting and / or light receiving devices into the display layer instead of into another layer, these devices can have a substantially unobstructed light path into or out of the screen. These devices can be integrated into the display screen instead of taking up space in a non-display area (e.g., the bezel of a mobile phone). This can allow for a reduction in the size of the bezel or elimination of the bezel.

[0225] Light transmitting devices integrated into the display layer can have a different wavelength, modulation speed, and / or power than the light sources used to form the image. In some cases, the light sources used to form the image can have a low modulation speed and / or low power output. The light transmitting devices can have a higher power output and / or faster modulation speed.

[0226] Figure 5A display matrix comprising display elements and photodiodes is shown. In other embodiments, display matrices comprising different optical elements or hardware components, in particular components of an optical front-end receiver, can be provided.

[0227] Figure 6 is a diagram of another embodiment in which detectors and transmitters used in optical wireless communication are integrated into a display matrix of a screen using different integration methods. As Figure 5 shown, Figure 6 A portion of the display layer shown in Figure 5 includes a four-fold repetition of different unit cells, which unit cells comprise a square of four elements by four elements. As Figure 6 shown, the constituent elements of the unit cell are a mix of display elements 72, 74, 76, photodiodes 78, and IR LEDs 80.

[0228] As Figure 5 shown, Figure 6 photodiodes 78, represented by black squares, and IR LEDs 80, represented by white squares, are shown. Front-end electronics 82 are represented by gray squares. Starting from the top left of the unit cell, the first row includes, in order from left to right, a red display element 72, a green display element 74, another red display element 72, and another green display element 74. The second row includes a blue display element 76, a photodiode 78, another blue display element 76, and another photodiode 78. The third row includes a red display element 72, a green display element 74, a first portion of front-end electronics 82, and a second portion of front-end electronics 82. The fourth row includes a blue display element 76, a photodiode 78, a third portion of front-end electronics 82, and an IR LED 80.

[0229] In some embodiments, each pixel of a display device includes an OWC transmitter and receiver, as well as common pixel circuitry and display elements. FIGS. 7(a) and 7(b) illustrate one example embodiment.

[0230] FIG. 7(a) illustrates a structure of an OLED and related circuitry, according to an embodiment. The related circuitry includes an aperture 110, an indium tin oxide (ITO) contact 112, a thin film transistor (TFT) driver 114, a capacitor line 116, a scan line 118, a data line 120, a switch TFT 122, a power line 124, and a capacitor 126.

[0231] Figure 7(b) shows a pixel structure for a display with integrated OWC transmitter and receiver. Figure 7(b) shows an aperture 90 comprising a red display element 92, a green display element 94, a blue display element 96. The pixel structure also has an IR LED 98 and a photodiode 100. Additional circuitry is shown schematically in Figure 7(b) and is included as part of the pixel. The additional circuitry can comprise optical front end circuitry for the OWC. The IR LED 98 and photodiode 100 and optical front end circuitry 102 allow the pixel to be used as part of an OWC device.

[0232] The pixel structure described above allows OWC functionality to be integrated into any display technology, for example, LCD, OLED or RGB LED. By utilising a plurality of such pixel structures in a display, the entire display area can be used for transmitting and receiving data, thus minimising any risk of signal loss. The pixel structure can also allow OWC to be integrated into any device with a display, including TVs, smart banners, monitors and the like. The pixel structure of Figure 7(b) can be incorporated into the display matrix shown in Figures 7(a) and 7(c). Figure 5 and Figure 6 .

[0233] In some embodiments, OWC signals can be generated by using the light emitting devices used for display. For example, one or more of the display LEDs can be modulated in order to transmit optical signals by the display. The data transmission can be synchronised with the display signal. For example, if the scene or image being displayed on the display screen is predominantly red, the red LEDs can be modulated to transmit the optical communication signal. If the scene moves to a predominantly blue scene, the blue LEDs can be modulated to transmit the optical communication signal, for example. In this case, the photodiode can be provided as part of the display screen itself or behind the display screen.

[0234] Further embodiments of the screen shown in Figures 2 to 4 and the display matrix shown in Figure 5 and Figure 6 are now described below. As described above, the light transmitting and light receiving devices can comprise an array of electro-optical devices. In some embodiments, the screen and / or display matrix is configured to comprise optical communication devices occupying different areas that are sensitive to different wavelengths.

[0235] In a first example embodiment, more than one OWC receiving area is provided. The more than one OWC receiving area can be provided on a different layer to the display, for example, on a backplane of the screen, as shown in Figures 2 to 4Alternatively, by selecting photodiodes in the unit cells that are sensitive to different wavelengths, more than one OWC receiving area can be formed as part of the display matrix. In some embodiments, the display matrix is arranged to have a first area comprising a repeating pattern of unit cells having photodiodes that are sensitive to a first wavelength, and a second area comprising a repeating pattern of unit cells having photodiodes that are sensitive to a second wavelength. Further areas that are sensitive to other wavelengths can be provided. In some embodiments, four receiving areas arranged in a quadrant can be provided.

[0236] Each receiving area is configured to receive OWC signals of a different optical wavelength. This can be achieved by providing appropriate filters or other optical elements that only allow light of a particular wavelength to pass through to the photodiodes of the receiving area. Multiple filters or other optical elements or a single filter or optical element can be used. Alternatively, a first OWC receiving area can comprise photodiodes of a first photodiode type, and a second OWC receiving area can comprise photodiodes of a second photodiode type, such that the first and second photodiode types are different and the first and second photodiode types are sensitive to light of a first and second wavelength, respectively. In some embodiments, more than two OWC areas with corresponding photodiode types can be provided.

[0237] In some embodiments, each receiving area is sensitive to light having a different wavelength in the IR spectrum.

[0238] In some embodiments, each receiving area is provided with an associated signal collection circuit for collecting and summing the analog detection signals from each photodiode in the receiving area. Thus, the collection circuit produces a summed signal or otherwise combined signal for each receiving area. Signals from photodiodes arranged at different distances from the collection circuit can take different times to reach the collection circuit. Thus, the collection circuit can have a processor or further synchronisation circuit configured to off-set the collection times from different diodes so that the collection signal of the collection circuit corresponds to the sum of the received signals at one time instant.

[0239] Additionally, in some embodiments, the collection circuit of each receiving area can have an associated amplifier for each receiving area. The amplifier of each receiving area can be arranged to amplify the summed signal and provide the amplified signal to an ADC.

[0240] By providing different receiving areas, multiplexing of the received signals can be achieved, in turn allowing the apparatus to receive signals on more than one optical wavelength channel. Thus, the data rate and / or bandwidth of the received signals can be increased.

[0241] Back to LiFi-supported screens (such as) Figure 2 As shown in the diagram and in the related embodiments described above, the display layer 36 includes a TOLED matrix, and the backplane layer 38 has a plurality of electro-optical devices, which in some embodiments include an IR LED 40 and a plurality of photodiodes 42. In another embodiment, the IR LED 40 is disposed on a different layer than the plurality of photodiodes. In some embodiments, the IR LED 40 is disposed on the display layer 36, and the plurality of photodiodes are disposed on the backplane layer. In some embodiments, the IR LED 40 is disposed on the backplane layer 38, and the plurality of photodiodes are disposed on the display layer 36.

[0242] In another embodiment, different epitaxial layers or films can be used to provide a transparent RGB transmitter and an IR detector.

[0243] As an example, within a semiconductor, the upper layer can be shallower, thus being more sensitive to shorter wavelengths of light (such as ultraviolet (UV)) or blue wavelengths, while deeper within the semiconductor, the device may be more sensitive to longer wavelengths, such as infrared light. In some embodiments, a thin-film OLED can be disposed as a stacked layer on the back of the display to receive infrared light.

[0244] Although in some of the embodiments described above the display device is configured to emit infrared light for uplink communication and receive visible light for downlink communication, it should be understood that alternative embodiments may use visible light to provide uplink communication and infrared light to provide downlink communication. This functionality can be achieved by using a photodiode sensitive to IR light or a suitable filter configured to filter the infrared light from the photodiode. Furthermore, a visible LED can be driven to generate a modulated optical signal.

[0245] It should be further understood that alternative embodiments may use infrared light to provide uplink and downlink communication. This functionality can be achieved by using an infrared-sensitive photodiode or a suitable filter configured to filter the infrared light from the photodiode and an infrared LED or a suitable filter configured to filter the infrared light from the LED. In further alternative embodiments, both uplink and downlink communication may use visible light. Moreover, in further alternative embodiments, UV light may be used for at least one of uplink and / or downlink communication.

[0246] In some embodiments, transmitting and receiving optical communication signals can operate in half-duplex or full-duplex mode.

[0247] In some embodiments, when receiving elements are provided on the backplane layer, filtering elements can be provided on the display layer, filtering light as it passes through the display layer.

[0248] It will be appreciated that suitable features from the display matrix embodiments can be combined with suitable features from the display screen embodiments.

[0249] As mentioned above, TOLED technology is used to address the problem of integrating optical detectors and emitters in electronic devices employing displays. However, other LED technologies can also be used. In some embodiments, a micro-LED array can be provided. In some embodiments, the micro-LED array can be implemented as part of a display matrix. In further embodiments, the micro-LED array can be incorporated as part of an at least partially transparent display screen. In particular, as part of the display screen embodiments, the micro-LED array can be provided as part of the display layer 36. In further embodiments, the micro-LED array or any other suitable LED device can be provided in the backplane layer as electro-optical devices 40 and 42. Figure 2

[0250] Thereby, further discussion of micro-LEDs is provided. The following provides some non-limiting examples of micro-LEDs suitable for optical wireless communication (OWC). The following focuses on the properties of micro-LEDs that are most useful for optical wireless communication.

[0251] ​Discussion on micro-LEDs can be found in Islim et al., “Towards 10 Gb / s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED,” Vol. 5, No. 2, April 2017, Photonics Research; Rajbhandari et al., “A review of gallium nitride LEDs for multigigabit-per-second visible light data communications,” Semicond. Sci. Technol. 32 (2017) 023001; Tsonev et al., “A 3-Gb / s Single-LED OFDM-Based Wireless VLC Link Using a Gallium Nitride pLED,” IEEE PHOTONICS TECHNOLOGY LETTERS, Vol. 26, No. 7, April 1, 2014; and Ferreira et al., “High Bandwidth GaN-Based Micro-LEDs for Multi-Gb / s Visible Light Communications,” IEEE PHOTONICS TECHNOLOGY LETTERS, Vol. 28, No. 19, October 1, 2016.

[0252] Some parameters of a successful OWC system can include suitable values for the following: electrical bandwidth; total radiant flux; thickness; beam output cone angle and conversion efficiency (electro-optical efficiency). By providing one or more micro-LED arrays on a chip, micro-LEDs can achieve suitable values for these parameters, as described below. Micro-LEDs can provide a single low profile light source.

[0253] Micro-LEDs can be used as sources, as described below. A first option is to provide a source comprising a micro-LED array having a total output power of 0.1 W and having an adapted output angular distribution within an area of 1 x 1 mm 2 A second option is to provide a multi-wavelength micro-LED array with different wavelength bands in sub-arrays having similar total power and area as option 1. A third option is to combine red, green, blue and infrared micro-LEDs in a structured array, while still maintaining the bandwidth advantage of individual micro-LEDs.

[0254] Figure 8 A micro-LED array is shown with an adapted output angular distribution. By providing an adapted output angular distribution, the micro-LED array does not need to use external optics to generate a required cone angle. Figure 8 A target cone angle of 60° full width half maximum is shown for the output from each micro-LED. However, this cone angle can be adapted to other cone angles. As another example, a cone angle of 90° full width half maximum (FWHM) is of interest.

[0255] Figure 8 The micro-LED array of Figure 1 has a light emitting layer 140 that emits light. Reflective sidewalls 142 are provided in a curved shape and are provided on one side of the light emitting layer 140. The sidewalls 142 are shaped to reflect and direct light into a light cone 144 having a cone angle. Figure 8 The n-contact 146 and p-contact 148 of the micro-LED are also shown.

[0256] To achieve an adapted output angle, multiple micro-LEDs can be combined to give a required peak output power of, for example, 100 mW from the array within a given target cone angle. For example, a desired operating wavelength can be 900 nm. The system also needs to retain the advantage that the micro-LEDs for LiFi applications have a high electrical bandwidth.

[0257] An initial list of design parameters for the micro-LED array and possible values for the parameters are as follows. The radiant flux can have a typical value of 0.1 W, which covers the combined output from the array. The maximum thickness of the dies and carrier can be 5 mm, optionally 1 mm, optionally 0.5 mm. The array can have a width of a typical value of 5 mm, optionally 1 mm. The array can have a length of a typical value of 5 mm, optionally 1 mm. A typical desired operating wavelength can be 900 nm, and a typical wavelength range can be 880 nm to 920 nm. The spectral bandwidth can have a typical value of 50 nm. The electrical bandwidth at 3 dB can have a typical minimum value of greater than 250 MHz, optionally 500 MHz. The electro-optical conversion efficiency can have a target value of 50%.

[0258] A second option for the micro-LED array is shown in Figure 9 . Figure 9 A multi-wavelength micro-LED array is shown. The array is subdivided into different regions, such that each region of the array is configured to operate at a different wavelength. For example, as Figure 9As shown, the first region operates at a first wavelength and the second region operates at a second wavelength. Each region of the array includes more than one micro-LED. Each region is individually addressed and modulated independently using a separate data stream. The wavebands in each section are separated over the spectral bandwidth and do not produce spectral overlap with any other wavebands from other regions of the array.

[0259] An initial list of design parameters for a micro-LED array and possible typical values for the parameters can be as follows. The radiant flux can have a typical value of 0.1 W, which covers the combined output from the array. The maximum thickness of the die and carrier can be 5 mm, optionally 1 mm, optionally 0.5 mm. The array can have a width of a typical value of 5 mm, optionally 1 mm. The array can have a length of a typical value of 5 mm, optionally 1 mm. The cone angle at full width half maximum can have a typical value of 60 degrees. The spectral bandwidth of each waveband can have a typical value of 25 nm. The electrical bandwidth at 3 dB can have a typical minimum value of greater than 250 MHz, optionally 500 MHz. The electro-optical conversion efficiency can have a target value of 50%.

[0260] As an example, for an array of Figure 8 , the typical values for the wavelength ranges can be as follows: for the first region, between 795 nm and 805 nm, typically 800 nm; for the second region, between 845 nm and 855 nm, typically 850 nm; for the third region, between 895 nm and 905 nm, typically 900 nm.

[0261] A third option is shown in Figure 10 . Figure 10 A structured addressable array is shown. The array can be considered a repeating pattern of unit cells. Each cell has at least four micro-LEDs, each operating at a different wavelength. As a non-limiting example, Figure 10 a unit cell is shown that includes, for example, red, green, blue, and IR micro-LEDs.

[0262] An initial list of design parameters for a structured micro-LED array and typical values for the parameters are as follows. The radiant flux can have a typical value of 0.1 W, which covers the combined output from the array. The maximum thickness of the die and carrier can be 5 mm, optionally 1 mm, optionally 0.5 mm. The array can have a width of a typical value of 7 cm. The array can have a length of a typical value of 11 cm. Each unit cell can have a size of 10 pm x 10 pm. The cone angle at full width half maximum can have a typical value of 120 degrees. The electrical bandwidth at 3 dB can have a typical minimum value of greater than 250 MHz, optionally 500 MHz. The electro-optical conversion efficiency can have a target value of 50%.

[0263] In some embodiments, a typical power output value for a single pixel with a diameter of 40-50 pm is about 2-5 mW. In some embodiments, a pixel with a diameter of about 10 pm has a typical power output value of 0.1 mW.

[0264] As an example, for an array in Figure 10 , four different micro-LEDs can operate in the following spectral bands: about 450 nm, about 530 nm, about 630 nm, and about 850 nm, where each spectral band has a typical bandwidth value of 50 nm.

[0265] In further embodiments, different light source technologies can be used as part of a screen. Different display technologies are discussed that can be used. These technologies can be used as part of a display screen (e.g., the screen of Figure 2 ) behind which a LiFi transmitter and / or receiver can be placed, and / or as part of an array containing LiFi elements (e.g., the display of Figure 5 ).

[0266] In some embodiments, TOLEDs, micro-LEDs, quantum dot LEDs (qLEDs), and light field displays can be used as part of a display screen behind which a LiFi transmitter and / or receiver can be placed. TOLEDs can provide the advantage that a standard LiFi platform can be used that does not contain light emitting display elements and / or that the display area can be curved. Furthermore, LiFi performance supports display performance by enhancing contrast. TOLEDs also provide the advantage of implementing a modular solution that can be adapted to different displays. This is advantageous if physical placement is important to obtain an improved field of view. In these embodiments, micro-LED arrays can bring a small form factor and the array can provide selective directivity. Micro-LEDs also provide high bandwidth and multi-wavelength options. In these embodiments, qLED displays can provide the advantage that the use of qLED displays will be able to increase uplink strength. For example, qLED displays use wavelength conversion elements to expand the color gamut. Since qLEDs are typically placed in a backlight, it is easy to modulate and send out as a LiFi uplink signal. The power penalty can be the efficiency of the transmitter driver compared to a standard backlight. qLEDs will eventually be able to increase the UL signal. Light field displays can provide the advantage of enabling bidirectional directivity.

[0267] As described above, different display technologies can be provided in an array comprising LiFi elements. In such embodiments, micro-LEDs can provide the advantage that a LiFi platform can be integrated into a backplane and can provide high optical power uplink per pixel. In such embodiments, qLED display technology can provide the advantage that LiFi components can be integrated into the backlight of a qLED display. Furthermore, qLED technology can provide a less complex and less costly alternative. Light field displays can provide the advantage that uplink and / or downlink efficiency can be improved.

[0268] Although the above embodiments have been described in connection with mobile telephones, they can be implemented in any suitable device having a display screen, for example, a mobile telephone, a tablet computer, a laptop or desktop computer, a domestic appliance or a point-of-sale device.

[0269] Embodiments have been described in which visible light is received and infrared light is transmitted. However, in other embodiments, any suitable wavelength of light can be transmitted and / or received, for example, visible light, infrared light or ultraviolet light.

[0270] Although components of the embodiments described herein have been implemented in software, it will be appreciated that any such components can be implemented in hardware, for example, in the form of an ASIC or FPGA, or can be implemented in a combination of hardware and software. Similarly, some or all of the hardware components of the embodiments described herein can be implemented in software or in a suitable combination of software and hardware.

[0271] It will be appreciated that the present application has been described herein by way of example only and that modifications can be made whilst remaining within the scope of the application. Each feature disclosed in the description and (where appropriate) the claims and drawing can be provided independently of, or in any appropriate combination with, any of the other features.

Claims

1. A display device comprising an optical wireless communication device and a display comprising an array of elements, the array of elements comprising: a plurality of display elements comprising red elements, green elements and blue elements, the plurality of display elements being configured to display an image to a user; and a plurality of light receiving elements configured to receive modulated light comprising a data signal from a further optical wireless communication device, wherein the optical wireless communication device is configured to decode the received modulated light to obtain the data signal encoded in the received modulated light; wherein the display device further comprises: the light receiving elements are distributed in the display in groups of one or more light receiving elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light receiving element, at least one red element, at least one green element, and at least one blue element.

2. The display device of claim 1, further comprising a plurality of light transmitting elements configured to transmit modulated light containing a data signal to a further optical wireless communication device, wherein the optical wireless communication device is configured to encode the data signal in the transmitted modulated light.

3. The display device of claim 2, further comprising at least one of a) and b): a) the light transmitting elements are distributed in the display in groups of one or more light transmitting elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting element, at least one red element, at least one green element, and at least one blue element; b) the light transmitting elements are arranged in one or more rows or one or more columns within or at the edge of the display.

4. The display device of any one of claims 1 to 3, wherein the modulated frequency of the transmitted modulated light is between 100 KHz and 1 PHz, and / or the modulated frequency of the received modulated light is between 100 KHz and 1 PHz.

5. The display device of any one of claims 1 to 3, wherein the modulated frequency of the transmitted modulated light is between 1 MHz and 100 GHz, and / or the modulated frequency of the received modulated light is between 1 MHz and 100 GHz.

6. The display device of any one of claims 2 to 3, wherein: the wavelength of the transmitted modulated light is different from the wavelength of the visible light transmitted by the display elements.

7. The display device of any one of claims 2 to 3, wherein the transmitted modulated light is infrared light.

8. The display device of any one of claims 2 to 3, wherein the output power of at least one of the light transmitting elements is different from the output power of at least one other of the display elements.

9. The display device according to any one of claims 1 to 3, wherein the light receiving elements are arranged in more than one light receiving area, such that at least some of the light receiving areas are configured to receive light having different wavelengths.

10. The display device of any of claims 1-3, further comprising a signal collection circuit for each light receiving area, the signal collection circuit configured to collect detection signals from each light receiving element in the light receiving area, and further configured to synchronize the collection of detection signals across light receiving areas.

11. The display device of any of claims 1-3, wherein a modulation scheme used to encode transmitted modulated light and / or a modulation scheme used to decode received modulated light comprises at least one of: on-off keying, phase shift keying, M-ary pulse amplitude modulation, M-ary quadrature amplitude modulation, and orthogonal frequency division multiplexing.

12. The display device of any of claims 2-3, wherein the plurality of light receiving elements comprises a plurality of photodiodes and / or the plurality of light transmitting elements comprises a plurality of light emitting diodes and / or laser diodes.

13. The display device of any of claims 1-3, wherein the display device comprises one layer or multiple layers.

14. The display device of any of claims 1-3, wherein the plurality of display elements comprises a plurality of at least partially transparent display elements.

15. The display device of claim 14, wherein: the at least partially transparent display elements comprise at least one of transparent organic light emitting diodes, micro-LEDs, quantum dot LEDs, and light field display elements.

16. The display device of claim 14, wherein the display device further comprises a plurality of non-transparent display elements.

17. The display device of any of claims 1-3, wherein the array of elements further comprises a plurality of optical front-end circuit elements.

18. The display device of claim 17, wherein each unit cell comprises at least one optical front-end circuit element, or at least one of the optical front-end circuit elements is arranged in one or more rows or one or more columns within or at the edge of the display.

19. The display device of claim 17, wherein at least one of the optical front-end circuit elements comprises: amplification circuit elements, buffer circuit elements, or multiplexing circuit elements.

20. The display device of any of claims 1-3, wherein the red elements, the green elements, and the blue elements are configured to transmit modulated light comprising data signals to a further optical wireless communication device.

21. The display device of any of claims 2-3, wherein the plurality of light transmitting elements and the plurality of light receiving elements further comprise or form part of at least one solar cell.

22. The display device of claim 21, wherein: the at least one solar cell is configured to at least partially power the display device.

23. The display device of claim 21, wherein the at least one solar cell is configured to detect light signals, optionally wherein the light signals comprise communication signals.

24. The display device of any one of Claims 1-3, wherein: at least some of the display elements are at least partially transparent; the display device further comprises at least one light transmitting device and / or light receiving device disposed behind the display; and / or at least one light receiving device is configured to transmit and / or receive light through at least a portion of the display.

25. The display device of claim 24, further comprising means for processing a signal representative of light received by the at least one light receiving device to identify, compensate and / or at least partially remove a component of the signal representative of light emitted by at least a portion of the display.

26. The display device of any one of claims 1-3, wherein the display device comprises means for at least partially compensating for optical effects caused by the display.

27. The display device of claim 26, wherein the means for at least partially compensating for optical effects caused by the display comprises at least one optical component configured to compensate for optical effects of the display.

28. The display device of claim 27, wherein the at least one optical component comprises at least one of: a lens; a lens array; a microlens array; a liquid crystal display; a polarizer; one or more filters.

29. The display device of claim 28, wherein the one or more filters comprises at least one of: an absorption filter; an interference filter; a Fabry-Perot filter; a dichroic filter; a bandpass filter; a tunable filter; a plasmonic filter.

30. The display device of claim 26, wherein at least partially compensating for the optical effects of the display device comprises changing, by at least one optical component of the display, a value of at least one parameter of the light transmitted and / or received by at least one light transmitting and / or light receiving device.

31. The display device of claim 26, wherein at least partially compensating for the optical effects of the display device comprises performing, by a processor of the display device, signal processing of light transmitted and / or received by at least one light transmitting and / or light receiving device.

32. The display device of any one of claims 1-3, wherein the display device is configured to change at least one characteristic of light emitted by at least a portion of the display and / or to change operation of the display during a time period in which at least one light transmitting and / or light receiving device transmits and / or receives light through at least a portion of the display.

33. The display device of claim 32, wherein the display device is configured such that the at least a portion of the display is turned off for a selected duration of time.

34. The display device of claim 33, wherein the display device is configured to turn off the at least a portion of the display for only a short period of time or to reduce intensity of the at least a portion of the display.

35. The display device of claim 33, wherein the display device is configured such that the at least a portion of the display is turned off in synchronization with a signal being transmitted or received.

36. The display device of claim 35, wherein the display device is configured to only turn off or reduce the intensity of the at least a portion of the display in synchrony with the modulation of the signal being transmitted or received for a short period of time.

37. The display device of claim 33, wherein at least some of the display elements are at least partially transparent; the display device further comprises at least one light transmitting device and / or light receiving device positioned behind the display; and the at least one light transmitting device and / or light receiving device is configured to transmit and / or receive light through at least a portion of the display; the at least one light receiving device comprises a sensor element of a camera, and wherein the period of time comprises a period of time in which the camera is taking an image.

38. The display device of claim 33, wherein the period of time is between one of a), b) or c): a) 0.001 seconds and 1 second; b) 0.001 seconds and 0.1 seconds; c) 0.01 seconds and 0.1 seconds.

39. The display of any one of claims 1-3, wherein at least some of the display elements are at least partially transparent; the display device further comprises at least one light transmitting device and / or light receiving positioned behind the display; and the at least one light transmitting device and / or light receiving device is configured to transmit and / or receive light through at least a portion of the display; the light transmitting device and / or light receiving device is concealed by the presence of the display.

40. The display device of any one of claims 1-3, wherein the optical wireless communication device is configured to operate in a half-duplex or full-duplex communication mode.

41. An electronic device comprising the display device of any one of the preceding claims.

42. The electronic device of claim 41, comprising at least one of a mobile phone, a tablet, a computer, a laptop, an automotive display, an aviation cockpit display, a television, a financial transaction terminal, and an industrial control panel.

43. A method of providing optical wireless communication using an optical wireless communication device, comprising: providing a plurality of display elements comprising red elements, green elements, and blue elements, the plurality of display elements configured to display an image to a user; and providing a plurality of light receiving elements configured to receive modulated light comprising a data signal from another optical wireless communication device, wherein the optical wireless communication device is configured to decode the received modulated light to obtain the data signal encoded in the received modulated light; wherein the optical wireless communication device further comprises: the light receiving elements are distributed in the display in groups of one or more light receiving elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light receiving element, at least one red element, at least one green element, and at least one blue element.

44. The method of providing optical wireless communication of claim 43, wherein the method further comprises: providing a plurality of light transmitting elements configured to transmit modulated light comprising a data signal to a further optical wireless communication device, wherein the optical wireless communication device is configured to encode the data signal in the transmitted modulated light; wherein the light transmitting elements are distributed in the display in the form of one or more groups of light transmitting elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting element, at least one red element, at least one green element, and at least one blue element.

45. The method of providing optical wireless communication of claim 44, wherein the method further comprises: providing a plurality of light transmitting elements configured to transmit modulated light comprising a data signal to a further optical wireless communication device, wherein the optical wireless communication device is configured to encode the data signal in the transmitted modulated light; wherein the light transmitting elements are arranged in one or more rows or one or more columns within the display or at the edge.

46. A display device comprising an optical wireless communication device and a display comprising an array of elements, the array of elements comprising: a plurality of display elements comprising red elements, green elements, and blue elements, the plurality of display elements configured to display an image to a user; and a plurality of light transmitting elements configured to transmit modulated light containing a data signal to a further optical wireless communication device, wherein the optical wireless communication device is configured to encode the data signal in the transmitted modulated light; and a plurality of light receiving elements configured to receive modulated light comprising a data signal from a further optical wireless communication device, wherein the optical wireless communication device is configured to decode the received modulated light to obtain the data signal encoded in the received modulated light; wherein the optical wireless communication device further comprises: the light transmitting elements are distributed in the display in the form of one or more groups of light transmitting elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting element, at least one red element, and at least one green element and at least one blue element.

47. The display device of claim 46, wherein the plurality of light receiving elements comprise a plurality of photodiodes and / or the plurality of light transmitting elements comprise a plurality of light emitting diodes and / or laser diodes.

48. The display device of claim 46, further comprising at least one of a), b), c): a) the wavelength of the received modulated light is different from the wavelength of the visible light transmitted by the display elements; b) the modulation frequency of the transmitted or received modulated light is between 100 KHz and 1 PHz; c) the display comprises at least one of: one layer or a plurality of layers.

49. The display device of claim 46 or 47, wherein the plurality of display elements comprises a plurality of at least partially transparent display elements.

50. The display device of claim 49, wherein the at least partially transparent display elements comprise at least one of transparent organic light emitting diodes, micro-LEDs, quantum dot LEDs, and light field display elements.

51. The display device of claim 46 or 47, wherein the array of elements further comprises a plurality of optical front-end circuit elements.

52. The display device of claim 49, wherein the display device further comprises a plurality of non-transparent display elements.

53. The display device of claim 46 or 47, further comprising at least one of a), b), c): a) the output power of the light transmitting elements is different from the output power of at least another of the display elements; b) each unit cell comprises at least one optical front-end circuit element; c) each unit cell comprises at least one optical front-end circuit element, wherein at least one of the optical front-end circuit elements is arranged in one or more rows or one or more columns within or at the edge of the display.

54. The display device of claim 46 or 47, wherein the display device further comprises a signal collection circuit for each light receiving area, the signal collection circuit being configured to collect detection signals from each light receiving element in the light receiving area, and further configured to synchronize the collection of detection signals over the light receiving area.

55. The display device of claim 46 or 47, wherein the display device further comprises a processor for processing signals representative of light received by the light receiving elements to identify, compensate, or at least partially remove at least one of the components in the signals representative of light transmitted by at least part of the display device.

56. The display device of claim 46 or 47, further comprising at least one of a) and b): a) the transmitted modulated light is of a different wavelength than the visible light emitted by the display elements; b) the modulation scheme used to encode the transmitted modulated light or the modulation scheme used to decode the received modulated light comprises at least one of on-off keying, phase-shift keying, M-ary pulse amplitude modulation, M-ary quadrature amplitude modulation, and orthogonal frequency division multiplexing.

57. The display device of claim 46 or 47, wherein the display device further comprises at least one of a light transmitting device or a light receiving device disposed behind the display; and at least one of the light transmitting device or the light receiving device is configured to at least one of transmit or receive light through at least a portion of the display.

58. The display device of claim 57, wherein the display device comprises means to at least partially compensate for optical effects produced by the display.

59. The display device of claim 57, wherein the display device comprises at least one optical component configured to at least partially compensate for an optical effect of the display, wherein the at least one optical component comprises at least one of: a lens, a lens array, a micro-lens array, a liquid crystal display, a polarizer, one or more filters, an absorption filter, an interference filter; a Fabry-Perot filter; a dichroic filter; a bandpass filter; an adjustable filter; a plasmonic filter.

60. The display device of claim 58, wherein at least partially compensating for the optical effect of the display comprises at least one of: a) changing, by at least one optical element of the display, a value of at least one parameter of light transmitted and / or received by the at least one light transmitting and / or light receiving device; b) performing, by a processor of the display device, signal processing of light transmitted and / or received by the at least one light transmitting and / or light receiving device.

61. The display device of claim 57, wherein the display device is configured to change at least one characteristic of light emitted by at least a portion of the display, and / or to change operation of the display during a time period in which the at least one light transmitting and / or light receiving device transmits and / or receives light through at least a portion of the display.

62. The display device of claim 61, wherein the display device is configured to comprise at least one of a) and b): a) at least a portion of the display is turned off for a selected duration of time; b) at least a portion of the display is turned off in synchronization with a signal being transmitted or received.

63. The display device of claim 60, wherein the display device is configured to turn off or reduce intensity of the at least a portion of the display only for a short period of time in synchronization with modulation of a signal being transmitted or received.

64. The display device of claim 57, wherein the light transmitting and / or light receiving devices are concealed by the presence of the display.

65. The display device of claim 46 or 47, further comprising at least one of a) and b): a) the plurality of light transmitting elements and the plurality of light receiving elements further comprise or form part of at least one solar cell; b) the optical wireless communication device is configured to utilize the light transmitting elements and the light receiving elements for half-duplex or full-duplex communication with another device.

66. An electronic device comprising the display device of any one of claims 46-65.

67. The electronic device of claim 66, the electronic device being at least one of a mobile phone, a tablet, a computer, a laptop, an automotive display, an aviation cockpit display, a television, a financial transaction terminal, and an industrial control panel.

68. A method of providing optical wireless communication on an optical wireless communication device, comprising: A plurality of display elements comprising a red element, a green element and a blue element are provided, the plurality of display elements being configured to display an image to a user; A plurality of light transmitting elements are provided, the plurality of light transmitting elements being configured to transmit modulated light comprising a data signal to a further optical wireless communication device, wherein the optical wireless communication device is configured to encode the data signal in the transmitted modulated light; A plurality of light receiving elements are provided, the plurality of light receiving elements being configured to receive modulated light comprising a data signal from a further optical wireless communication device, wherein the optical wireless communication device is configured to decode the received modulated light to obtain the data signal encoded in the received modulated light; wherein the optical wireless communication device further comprises: The light transmitting elements are distributed in the display in groups of one or more light transmitting elements, wherein one or more of the groups are at least partially surrounded by display elements, such that the array of elements comprises a repeating arrangement of unit cells, each unit cell comprising at least one light transmitting element, at least one red element and at least one green element and at least one blue element.

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