Patent Description:
Sensors for face recognition, autofocus or depth sensing use an active infrared illumination unit. Displays of devices like smartphones tend to occupy the complete front side of the device such that the camera is located under the display. An exemplary liquid crystal display with a microlens array for condensing light is proposed in document <CIT>. As the average transparency of displays is limited, the illumination units become inefficient when the light needs to pass through the display. Sensors in mobile devices like smartphones run on a limited power budget due to the limited battery capacity of the mobile device. Current display devices are only transparent to a certain degree, leading to a higher power consumption of the illumination unit compared to devices in which the illumination unit is not mounted under the display.

The absorbed light causes punctual heating at the display which may cause an aging effect on the display pixels. Furthermore, the heat causes punctual expansion of the display, which contributes to glass fracture. The light reflected by the display may further impair cameras located under the display. Another point is the additionally generated dark current/leakage current caused by the additional backlight illumination of the light source below the display.

Document <CIT> relates to an electronic device consisting of a proximity sensor component and display screen component. The proximity sensor component is utilized for electronic devices with OLED screens where there are gaps between pixels of the OLED screen and the pixel driving circuit. The proximity sensor component has a light emitting body as well as a light guiding structure that creates a path of light to bypass the transmission gap. This ensures that there is no negative impact on the OLED pixel organic light-emitting material or driving circuit, without sacrificing extra display space on the OLED screen while meeting the requirement for full-screen development.

Document <CIT> relates to a display component and an electronic device. The display component includes a display screen and a sensor component located on one side of the screen. The light signals emitted from the display screen contain a target color signal with a wavelength within the target range. The sensor component consists of an ambient light sensor, which is connected to a light filter component between the ambient light sensor and the display screen. The light filter component filters the external ambient light signal passing through the display screen and transmits the filtered ambient light signal to the ambient light sensor. The color of the filtered ambient light signal is the target color, and the wavelength is outside the target wavelength range. This solution reduces the brightness of the display screen's impact on the ambient light sensor's light detection, enabling the ambient light sensor to accurately sense the external ambient light signals and improve the accuracy of electronic devices controlling the display screen's brightness.

There may be a demand for improved light guidance for under-display illumination structures.

The invention is defined by the subject matter of the appended claims. The electronic device comprises a display device comprising a plurality of light-emitting elements for displaying an optical image on a front side of the display device. Further, the electronic device comprises a plurality of illumination elements configured to emit light for illuminating a scene in front of the front side of the display device. The display device is arranged between the plurality of illumination elements and the scene. The display device comprises a first display region exhibiting a first transmissivity for the light emitted by the plurality of illumination elements and a second display region exhibiting a second transmissivity for the light emitted by the plurality of illumination elements. The first transmissivity is higher than the second transmissivity. The electronic device additionally comprises at least one optical element arranged between the plurality of illumination elements and the display device. The at least one optical element is configured to focus the light emitted by the plurality of illumination elements through the first display region. Further, the electronic device comprises an optical sensor configured to measure a fraction of the light emitted by the plurality of illumination elements that is reflected back from the scene. The display device is arranged between the optical sensor and the scene. The electronic device additionally comprises control circuitry configured to receive object information indicating a position or a movement of an object in the scene. The control circuitry is configured to determine a part of the scene that likely contains the object based on the object information. In addition, the control circuitry is configured to selectively control light emission by individual illumination elements of the plurality of illumination elements in order to selectively illuminate the part of the scene that likely contains the object.

Another example relates to a method for an electronic device comprising a display device, a plurality of illumination elements, at least one optical element, an optical sensor and control circuitry. The display device comprises a plurality of light-emitting elements for displaying an optical image on a front side of the display device. The at least one optical element is arranged between the plurality of illumination elements and the display device. The display device is arranged between the optical sensor and the scene. The method comprises emitting light for illuminating a scene in front of the front side of the display device by the plurality of illumination elements. The display device is arranged between the plurality of illumination elements and the scene. The display device comprises a first display region exhibiting a first transmissivity for the light emitted by the plurality of illumination elements and a second display region exhibiting a second transmissivity for the light emitted by the plurality of illumination elements. The first transmissivity is higher than the second transmissivity. The method further comprises focusing the light emitted by the plurality of illumination elements through the first display region using the at least one optical element. In addition, the method comprises measuring, by the optical sensor, a fraction of the light emitted by the plurality of illumination elements that is reflected back from the scene. The method comprises receiving, by the control circuitry, object information indicating a position or a movement of an object in the scene. In addition, the method comprises determining, by the control circuitry, a part of the scene that likely contains the object based on the object information. Further, the method comprises selectively controlling, by the control circuitry, light emission by individual illumination elements of the plurality of illumination elements in order to selectively illuminate the part of the scene that likely contains the object.

When two elements A and B are combined using an "or", this is to be understood as disclosing all possible combinations, i.e. only A, only B as well as A and B, unless expressly defined otherwise in the individual case.

<FIG> illustrates an electronic device <NUM> such as, e.g., a smartphone, a tablet-computer or a laptop-computer. However, it is to be noted that the electronic device <NUM> may be any other electronic device as well.

The electronic device <NUM> comprises a display device <NUM>. The display device <NUM> comprises a plurality of light-emitting elements (circuitries, devices) for displaying an optical image on a front side <NUM> of the display device <NUM>. The front side <NUM> of the display device <NUM> is the side of the display device <NUM> that can be seen by a user of the electronic device <NUM>. For example, the plurality of light-emitting elements may be arranged in an array as pixels for displaying the optical image. The display device <NUM> may be formed according to a display technology. For example, the display device <NUM> may be a Light Emitting Diode (LED) display, an Organic LED (OLED) display, a Liquid Crystal Display (LCD) or a micro LED display. However, it is to be noted that any other display technology may be used as well for the display device <NUM>.

The display device <NUM> may cover (substantially) the entire front surface of the electronic device <NUM> as illustrated in <FIG>. In other examples, the display device <NUM> may cover only a fraction of the electronic device <NUM>'s front surface.

The electronic device <NUM> further comprises at least one illumination element (circuit, device). In the example of <FIG>, one illumination element <NUM> is illustrated. However, the electronic device <NUM> may optionally comprise plural illumination elements. The at least one illumination element <NUM> is configured to emit light <NUM> for illuminating a scene <NUM> in front of the front side <NUM> of the display device <NUM>. The at least one illumination element <NUM> is arranged within the electronic device <NUM> at a back side of the display device <NUM>. In other words, the display device <NUM> is arranged between the at least one illumination element <NUM> and the scene <NUM>. As a consequence, the light <NUM> needs to transmit through the display device <NUM> in order to reach the scene <NUM>. In general, the light <NUM> emitted by the illumination element <NUM> may be of any desired (target) wavelength (wavelength range). For example, the at least one illumination element <NUM> may be configured to emit infrared light as the light <NUM> (i.e. the wavelength of the light <NUM> is between approx. <NUM> and approx. The at least one illumination element <NUM> may, e.g., comprise/be one or more LEDs and/or one or more laser diodes (e.g. one or more Vertical-Cavity Surface-Emitting Lasers, VCSELs).

The display device <NUM> exhibits a non-uniform transmissivity for the light <NUM> emitted by the at least one illumination element <NUM>. As indicated in <FIG>, the display device <NUM> comprises a first display region <NUM> exhibiting a first transmissivity for the light <NUM> emitted by the at least one illumination element. Further, the display device <NUM> comprises a second display region <NUM> exhibiting a second transmissivity for the light <NUM> emitted by the at least one illumination element <NUM>. The first transmissivity is higher than the second transmissivity. That is, the fraction of the light <NUM> that is transmitted through the display device <NUM> per illuminated unit area of the display device <NUM> is higher in the first display region <NUM> than in the second display region <NUM>. In other words, the light <NUM> can more easily transmit through first display region <NUM> than through the second display region <NUM>. The first display region <NUM> and the second display region <NUM> are different integral parts of the display device <NUM>. The first display region may be a coherent (connected) region of the display device <NUM> or comprise a plurality of non-coherent (discontinuous) sub-regions.

In order to achieve the increased transparency for the light <NUM> in the first display region <NUM>, a substrate (not illustrated) of the display device <NUM> may, e.g., be covered in the first display region <NUM> per unit area to a lesser extent with electronic circuitry of the display device <NUM> than in the second display region <NUM>. For example, less electronic circuitry of the display device may be arranged in the first display region <NUM> compared to the second display region <NUM>. Alternatively or additionally, electronic circuitry of a smaller form factor may be arranged in the first display region <NUM> compared to the second display region <NUM>. For example, micro LEDs may be used in the first display region while OLEDs may be used in the second region. As micro LEDs are smaller in size than OLEDs, the substrate of the display device <NUM> is covered in the first display region <NUM> per unit area to a lesser extent with LEDs than in the second display region <NUM>. In other examples, a resolution of the display may be reduced in the first display region <NUM> compared to the second display region <NUM> such that less electronic circuitry (e.g. less LEDs) is provided per unit area on the substrate for the first display region <NUM> than for the second display region <NUM>. In other words, single light emitting devices/pixels or sets of light emitting devices/pixels may be omitted in the first display region <NUM> compared to the second display region <NUM>.

In other examples, the arrangement of the light emitting devices/pixels may be altered in the first display region <NUM> compared to the second display region <NUM>. Additionally or alternatively, the circuit layout of the light emitting devices/pixels may be altered in the first display region <NUM> compared to the second display region <NUM>.

However, it is to be noted that the above examples for increasing the transparency for the light <NUM> in the first display region <NUM> compared to the second display region <NUM> are not limiting the proposed architecture. Also other designs of the display device may provide increased transparency for the light <NUM> in the first display region <NUM>.

In order to make use of the non-uniform transmissivity of the display device <NUM> for the light <NUM>, the electronic device <NUM> comprises at least one optical element (device) <NUM> arranged between the at least one illumination element <NUM> and the display device <NUM>. The at least one optical element <NUM> is configured to focus the light <NUM> emitted by the at least one illumination element <NUM> through the first display region <NUM> such that the light <NUM> transmits (passes) through the first display region <NUM> rather than through the second display region <NUM>. In other words, at least one optical element <NUM> is configured to direct the light <NUM> emitted by the at least one illumination element <NUM> towards the first display region <NUM> such that a light density of the light <NUM> transmitting through the first display region <NUM> is higher than a light density of the light <NUM> transmitting through the second display region <NUM>. In the example of <FIG>, one optical element <NUM> is illustrated. However, the electronic device <NUM> may optionally comprise plural optical elements arranged between the at least one illumination element <NUM> and the display device <NUM> for focusing the light <NUM> emitted by the at least one illumination element <NUM> through the first display region <NUM>.

As illustrated in <FIG>, the at least one optical element <NUM> may be arranged on the back side of the display device <NUM> at a position of the first display region <NUM> (i.e. facing the first display region <NUM>). However, the proposed architecture is not limited thereto. In alternative examples, the at least one optical element <NUM> may be spaced apart from the display device <NUM> (e.g. an air gap may be formed between the at least one optical element <NUM> and the display device <NUM>). According to examples of the present disclosure, dimensions of the at least one optical element <NUM> may be greater than that of the first display region <NUM> in at least one spatial direction. In other words, the at least one optical element <NUM> may stretch beyond the first display region <NUM> in at least one spatial direction. For example, the dimensions of the at least one optical element <NUM> may be greater than that of the first display region <NUM> in two spatial directions that are perpendicular with respect to each other and with respect to the front side <NUM> of the display device <NUM>. For example, the at least one optical element <NUM> may be a lens or a lens system (comprising a plurality of lenses).

As the light <NUM> is focused through a region of the display <NUM> with increased transparency for the light <NUM>, a higher fraction of the light <NUM> can transmit through the display device <NUM>. Accordingly, a power of the light <NUM> may be reduced compared to conventional under-display illumination structures. As a consequence, a power consumption of the at least one illumination element <NUM> may be reduced compared to conventional under-display illumination structures. Further, heating of the display <NUM> via the light <NUM> and, hence, an expansion of the display device <NUM> may be reduced. Therefore, the likelihood of a display damage (e.g. glass fracture) may be reduced.

Although not explicitly illustrated in <FIG>, the electronic device <NUM> may optionally further comprise at least one diffusion element which is configured to diffuse the light focused through the first display region <NUM>. For example, the diffusion element may be arranged between the at least one optical element <NUM> and the first display region <NUM>, be formed in the display device <NUM> (e.g. within the first display region <NUM>) or be formed on the front side <NUM> of the display device <NUM> (e.g. within the first display region <NUM>). By diffusing the light via the at least one diffusion element, a width of the light focused through the first display region <NUM> may be increased such that a larger part of the scene <NUM> may be illuminated at once. Further, a more even light distribution may be achieved by diffusing the light.

In other words, an (e.g. infrared) illumination unit <NUM> is located behind a display device <NUM> according to the proposed technique. The (e.g. typically) narrow beam of the illumination unit <NUM> is directed at a focusing element <NUM>, which is located rather close to the display device <NUM>. As described above, display devices typically do not have a homogenous transparency. As a consequence, the focusing element <NUM> focuses the light beam onto an area of the display device <NUM> with increased transparency. As a side effect, the light gets diffused and the width of the light beam is increased for illuminating a larger part of the scene.

As indicated in <FIG>, the electronic device <NUM> may optionally further comprise an optical sensor <NUM>. The optical sensor <NUM> is configured to measure reflected light from the scene, i.e. the optical sensor <NUM> is configured to measure the fraction of the light <NUM> that is reflected back from the scene <NUM>. The optical sensor may, e.g., comprise a Photonic Mixer Device, PMD, or a Charge-Coupled Device, CCD for measuring the reflected light from the scene. The optical sensor <NUM> is arranged within the electronic device <NUM> at the back side of the display device <NUM>. In other words, the display device <NUM> is arranged between the optical sensor <NUM> and the scene <NUM>. Accordingly, the reflected light from the scene transmits through the display device <NUM> before it reaches the optical sensor <NUM>.

For example, the optical sensor <NUM> may be a Time-of-Flight (ToF) sensor. The optical sensor <NUM> may alternatively be part of a camera such as, e.g., a ToF camera, an active stereo camera or any other infrared camera. In other examples, the optical sensor <NUM> may be part of distance measuring device (e.g. a single pixel ToF camera for auto focus adjustment). Accordingly, the optical sensor <NUM> may comprise processing circuitry configured to determine, based on the measured reflected light from the scene, <NUM> at least one of an image of at least part of the scene <NUM> or a distance of the electronic device <NUM> to at least one object (such as the head <NUM>) in the scene <NUM>.

The measurements of the optical sensor <NUM> may further be used for controlling the operation of the at least one illumination element <NUM>. For example, the electronic device may further comprise control circuitry <NUM> configured to receive an output signal <NUM> of the optical sensor <NUM>. The output signal <NUM> indicates an intensity of the reflected light measured by the optical sensor <NUM>. Accordingly, the control circuitry <NUM> may be further configured to control a light emission intensity of the at least one illumination element <NUM> based on the output signal <NUM>. In other words, the at least one illumination element <NUM> may be controlled based on the received signal strength of the optical sensor <NUM> (which may, e.g., be part of a camera). For example, the above control technique may allow to give dark objects in the scene <NUM> more light.

Although not illustrated in <FIG>, the electronic device <NUM> may optionally comprise further circuitry/elements such as, e.g., one or more microphones, one or more loudspeakers, one or more antennas, one or more application processors, one or more radio frequency transmitters and/or receivers for mobile communication, one or more data storages, one or more batteries, etc..

In the example of <FIG>, the electronic device <NUM> comprises a single illumination element <NUM>. As described above, the electronic device <NUM> may optionally comprise further illumination elements. An exemplary electronic device <NUM> comprising two illumination elements <NUM>-<NUM> and <NUM>-<NUM> is illustrated in <FIG>. In the following, mostly the differences between the electronic device <NUM> and the electronic device <NUM> will be highlighted. Unless explicitly excluded, the electronic device <NUM> may exhibit each feature / comprise each element described above with respect to <FIG>. The electronic device <NUM> is an example of an electronic device according to the proposed technique that comprises a plurality of illumination elements. Although the electronic device <NUM> comprises exactly two illumination elements <NUM>-<NUM> and <NUM>-<NUM>, it is to be noted that electronic devices according to the proposed technique may comprise more than two illumination elements for illuminating the scene <NUM>.

In the example of <FIG>, the first display region comprises two sub-regions <NUM>-<NUM> and <NUM>-<NUM>. However, the proposed technique is not limited thereto. The first display region may comprise any number of sub-regions. Each of the sub-regions <NUM>-<NUM> and <NUM>-<NUM> exhibits the same characteristics as the first display region <NUM> described above with reference to <FIG>.

A respective optical element <NUM>-<NUM>, <NUM>-<NUM> is arranged between each of the two illumination elements <NUM>-<NUM>, <NUM>-<NUM> and the display device <NUM> for focusing the light <NUM>-<NUM>, <NUM>-<NUM> emitted by the respective illumination element <NUM>-<NUM>, <NUM>-<NUM> through the first display region. In particular, the optical elements <NUM>-<NUM>, <NUM>-<NUM> focus the light <NUM>-<NUM>, <NUM>-<NUM> emitted by the respective illumination element <NUM>-<NUM>, <NUM>-<NUM> through the two sub-regions <NUM>-<NUM> and <NUM>-<NUM> of the first display region. However, it is to be noted that optionally two or more optical elements may be respectively arranged between at least one of the two illumination elements <NUM>-<NUM>, <NUM>-<NUM> and the display device <NUM> for focusing the light <NUM>-<NUM>, <NUM>-<NUM> emitted by the respective illumination element <NUM>-<NUM>, <NUM>-<NUM> through the first display region. For example, two optical elements may be arranged between the illumination element <NUM>-<NUM> and the display device <NUM> for focusing the light <NUM>-<NUM> emitted by the illumination element <NUM>-<NUM> through the sub-region <NUM>-<NUM> of the first display region.

In more general terms, an electronic device according to the proposed technique may comprise a plurality of illumination elements and a plurality of optical elements. At least one of the plurality of optical elements may be arranged between each of the plurality of illumination elements and the display device for focusing the light emitted by the respective illumination element through the first display region. Optionally, at least two of the plurality of optical elements may respectively be arranged between at least part of the plurality of illumination elements and the display device for focusing the light emitted by the respective illumination element through the first display region. As indicated in <FIG>, the first display region may comprise a plurality of sub-regions such that the plurality of optical elements are configured to focus the light emitted by the individual illumination elements of the plurality of illumination elements through different ones of the plurality of sub-regions.

In other words, there may be multiple light sources and multiple focusing elements. Further, each of these light sources may have multiple focusing elements.

The illumination elements <NUM>-<NUM> and <NUM>-<NUM> may be controlled commonly or individually by the control circuitry <NUM>. For example, the control circuitry <NUM> may be configured to selectively control light emission by individual ones of the illumination elements <NUM>-<NUM> and <NUM>-<NUM> in order to adjust a target illumination characteristic. As described above, an electronic device according to the proposed technique may comprise more than two illumination units. Accordingly, in more general terms, the control circuitry <NUM> may be configured to selectively control light emission by individual illumination elements of a plurality of illumination elements of the electronic device in order to adjust the target illumination characteristic. The target illumination characteristic denotes a desired illumination of the scene <NUM> or at least part thereof. For example, the target illumination characteristic may define one or more parts of the scene <NUM> that are to be illuminated. Further, the target illumination characteristic may define a common or individual light intensity for the illumination of the one or more parts of the scene <NUM>.

For example, the control circuitry <NUM> may be configured to receive object information indicating a position or a movement of an object such as the head <NUM> in the scene <NUM>. Further, the control circuitry <NUM> may be configured to determine a part of the scene <NUM> that likely contains the object based on the object information and selectively control light emission by individual illumination elements of the plurality of illumination elements in order to selectively illuminate the part of the scene that likely contains the object. For example, if the object information indicates that the head <NUM> is in the upper part of the scene <NUM>, the control circuitry <NUM> may determine that the upper part of the scene <NUM> likely contains the head. Accordingly, the control circuitry <NUM> may, e.g., only activate the illumination element <NUM>-<NUM> in order to illuminate the upper part of the scene <NUM> that likely contains the head <NUM>. The object information may, e.g., be provided by a tracking application executed on the electronic device <NUM> or a sensor of the electronic device <NUM>.

In more general terms, when multiple light sources and focusing elements are used, the directions of the light sources may be adjusted individually in order to achieve a target illumination characteristic (e.g. for focusing the light on the expected object location or for getting an even light distribution). The illumination unit and/or the focusing element may be arranged so that the center of the exiting light beam is not perpendicular to the display device (e.g. a direct light beam to the expected object direction may be sent out).

For example, the individual control of the light sources (which exhibit different directional characteristics) may enable to track an object with the combined light beam. Accordingly, less light may be wasted for tracking the object. This is illustrated in <FIG>.

<FIG> illustrates an electronic device <NUM>. The electronic device <NUM> comprises a plurality of illumination elements. For reasons of simplicity, the plurality of illumination elements are represented by the single illumination element <NUM> in <FIG>. Similar to what is described above, the plurality of illumination elements are arranged at the back side of a display <NUM>.

Further, the electronic device <NUM> comprises a plurality of optical elements arranged between each of the plurality of illumination elements and the display device <NUM> for focusing the light emitted by the respective illumination element through the first display region of the display device <NUM>. As described above, the first display region exhibits a higher transmissivity for the light emitted by the plurality of illumination elements compared to the remaining display region. For reasons of simplicity, the plurality of optical elements are represented by the single optical element <NUM> in <FIG>.

By selectively activating individual illumination elements of the plurality of illumination elements, a target illumination characteristic can be adjusted. In particular, a shape of the light beam <NUM> caused by the overlapping light emissions of selectively activated illumination elements can be adjusted in order to selectively illuminate a target (desired) part of the scene <NUM>.

For example, if the control circuitry <NUM> that controls the plurality of illumination elements receives object information indicating a position or a movement of the head <NUM> in the scene <NUM>. The control circuitry <NUM> determines a part of the scene <NUM> that likely contains the head <NUM> based on the object information. Accordingly, the control circuitry selectively activates individual illumination elements of the plurality of illumination elements in order to selectively illuminate the part of the scene <NUM> that likely contains the head. Based on updated object information, the shape of the light beam <NUM> may be continuously changed (adjusted) such that the light beam <NUM> follows the movement of the head <NUM>. Accordingly, an efficient tracking of the head is enabled. For example, the above approach may be used for face recognition applications.

In order to summarize the processing in the above examples, <FIG> illustrates a flowchart of an exemplary method <NUM> for an electronic device. As described above, the electronic device comprises a display device, at least one illumination element and at least one optical element. The display device comprises a plurality of light-emitting elements for displaying an optical image on a front side of the display device. The at least one optical element is arranged between the at least one illumination element and the display device.

The method <NUM> comprises emitting <NUM> light for illuminating a scene in front of the front side of the display device by the at least one illumination element. The display device is arranged between the at least one illumination element and the scene. The display device comprises a first display region exhibiting a first transmissivity for the light emitted by the at least one illumination element and a second display region exhibiting a second transmissivity for the light emitted by the at least one illumination element. The first transmissivity is higher than the second transmissivity. The method <NUM> further comprises focusing <NUM> the light emitted by the at least one illumination element through the first display region using the at least one optical element.

As the light is directed towards a region of the display device with increased transparency according to the method <NUM>, a higher fraction of the light can transmit through the display device compared to conventional approaches.

More details and aspects of the method <NUM> are explained in connection with the proposed technique or one or more examples described above (e.g. <FIG>). The method <NUM> may comprise one or more additional optional features corresponding to one or more aspects of the proposed technique or one or more examples described above.

The examples as described herein may be summarized as follows:
Some examples relate to an electronic device. The electronic device comprises a display device comprising a plurality of light-emitting elements for displaying an optical image on a front side of the display device. Further, the electronic device comprises at least one illumination element configured to emit light for illuminating a scene in front of the front side of the display device. The display device is arranged between the at least one illumination element and the scene. The display device comprises a first display region exhibiting a first transmissivity for the light emitted by the at least one illumination element and a second display region exhibiting a second transmissivity for the light emitted by the at least one illumination element. The first transmissivity is higher than the second transmissivity. The electronic device additionally comprises at least one optical element arranged between the at least one illumination element and the display device. The at least one optical element is configured to focus the light emitted by the at least one illumination element through the first display region.

In some examples, the electronic device comprises a plurality of optical elements arranged between the at least one illumination element and the display device for focusing the light emitted by the at least one illumination element through the first display region.

In some examples, at least one of the plurality of optical elements is arranged between each of the plurality of illumination elements and the display device for focusing the light emitted by the respective illumination element through the first display region.

In alternative examples, at least two of the plurality of optical elements are respectively arranged between at least part of the plurality of illumination elements and the display device for focusing the light emitted by the respective illumination element through the first display region.

According to some examples, the first display region comprises a plurality of sub-regions, wherein the plurality of optical elements are configured to focus the light emitted by the individual illumination elements of the plurality of illumination elements through different ones of the plurality of sub-regions.

In some examples, the electronic device further comprises control circuitry configured to selectively control light emission by individual illumination elements of the plurality of illumination elements in order to adjust a target illumination characteristic.

According to some examples, the control circuitry is configured to: receive object information indicating a position or a movement of an object in the scene; determine a part of the scene that likely contains the object based on the object information; and selectively control light emission by individual illumination elements of the plurality of illumination elements in order to selectively illuminate the part of the scene that likely contains the object.

In some examples, a substrate of the display device is in the first display region per unit area to a lesser extent covered with electronic circuitry of the display device than in the second display region.

According to some examples, the at least one optical element is further configured to diverge the light emitted by the at least one illumination element.

In some examples, the electronic device further comprises an optical sensor configured to measure reflected light from the scene.

According to some examples, the electronic device further comprises control circuitry configured to: receive an output signal of the optical sensor indicating an intensity of the reflected light measured by the optical sensor; and control a light emission intensity of the at least one illumination element based on the output signal.

In some examples, the optical sensor comprises processing circuitry configured to determine, based on the measured reflected light from the scene, at least one of an image of at least part of the scene or a distance of the electronic device to at least one object in the scene.

According to some examples, the at least one illumination element is configured to emit infrared light.

In some examples, the electronic device is one of a smartphone, a tablet-computer and a laptop-computer.

Other examples relate to a method for an electronic device comprising a display device, at least one illumination element and at least one optical element. The display device comprises a plurality of light-emitting elements for displaying an optical image on a front side of the display device. The at least one optical element is arranged between the at least one illumination element and the display device. The method comprises emitting light for illuminating a scene in front of the front side of the display device by the at least one illumination element. The display device is arranged between the at least one illumination element and the scene. The display device comprises a first display region exhibiting a first transmissivity for the light emitted by the at least one illumination element and a second display region exhibiting a second transmissivity for the light emitted by the at least one illumination element. The first transmissivity is higher than the second transmissivity. The method further comprises focusing the light emitted by the at least one illumination element through the first display region using the at least one optical element.

Examples of the present disclosure may provide a light focusing element for under-display illumination units. When using a light source behind a display device, the focusing element may allow to let light pass through (more) transparent areas of the display and to simultaneously diverge the light to illuminate the scene in front of the display.

Claim 1:
An electronic device (<NUM>, <NUM>, <NUM>), comprising:
a display device (<NUM>) comprising a plurality of light-emitting elements for displaying an optical image on a front side of the display device (<NUM>);
a plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) configured to emit light (<NUM>) for illuminating a scene (<NUM>) in front of the front side of the display device (<NUM>), wherein the display device (<NUM>) is arranged between the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) and the scene (<NUM>), wherein the display device (<NUM>) comprises a first display region (<NUM>) exhibiting a first transmissivity for the light (<NUM>) emitted by the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) and a second display region (<NUM>) exhibiting a second transmissivity for the light (<NUM>) emitted by the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>), the first transmissivity being higher than the second transmissivity;
at least one optical element (<NUM>) arranged between the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) and the display device (<NUM>), wherein the at least one optical element (<NUM>) is configured to focus the light emitted by the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) through the first display region (<NUM>);
an optical sensor (<NUM>) configured to measure a fraction of the light (<NUM>) emitted by the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) that is reflected back from the scene (<NUM>), wherein the display device (<NUM>) is arranged between the optical sensor (<NUM>) and the scene (<NUM>); and
control circuitry (<NUM>) configured to:
receive object information indicating a position or a movement of an object in the scene (<NUM>);
determine a part of the scene (<NUM>) that likely contains the object based on the object information; and
selectively control light emission by individual illumination elements of the plurality of illumination elements (<NUM>-<NUM>, <NUM>-<NUM>) in order to selectively illuminate the part of the scene (<NUM>) that likely contains the object.