The present disclosure relates to an electronic device and a method for an electronic device.
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. 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.
Hence, there may be a demand for improved light guidance for under-display illumination structures.
The demand may be satisfied by the subject matter of the appended claims.
An example relates 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.
Another example relates 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.
Some examples of apparatuses and/or methods will be described in the following by way of example only, and with reference to the accompanying figures, in which
Some examples are now described in more detail with reference to the enclosed figures. However, other possible examples are not limited to the features of these embodiments described in detail. Other examples may include modifications of the features as well as equivalents and alternatives to the features. Furthermore, the terminology used herein to describe certain examples should not be restrictive of further possible examples.
Throughout the description of the figures same or similar reference numerals refer to same or similar elements and/or features, which may be identical or implemented in a modified form while providing the same or a similar function. The thickness of lines, layers and/or areas in the figures may also be exaggerated for clarification.
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. As an alternative wording for the same combinations, “at least one of A and B” or “A and/or B” may be used. This applies equivalently to combinations of more than two elements.
If a singular form, such as “a”, “an” and “the” is used and the use of only a single element is not defined as mandatory either explicitly or implicitly, further examples may also use several elements to implement the same function. If a function is described below as implemented using multiple elements, further examples may implement the same function using a single element or a single processing entity. It is further understood that the terms “include”, “including”, “comprise” and/or “comprising”, when used, describe the presence of the specified features, integers, steps, operations, processes, elements, components and/or a group thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components and/or a group thereof.
The electronic device 100 comprises a display device 110. The display device 110 comprises a plurality of light-emitting elements (circuitries, devices) for displaying an optical image on a front side 113 of the display device 110. The front side 113 of the display device 110 is the side of the display device 110 that can be seen by a user of the electronic device 100. For example, the plurality of light-emitting elements may be arranged in an array as pixels for displaying the optical image. The display device 110 may be formed according to a display technology. For example, the display device 110 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 110.
The display device 110 may cover (substantially) the entire front surface of the electronic device 100 as illustrated in
The electronic device 100 further comprises at least one illumination element (circuit, device). In the example of
The display device 110 exhibits a non-uniform transmissivity for the light 121 emitted by the at least one illumination element 120. As indicated in
In order to achieve the increased transparency for the light 121 in the first display region 111, a substrate (not illustrated) of the display device 110 may, e.g., be covered in the first display region 111 per unit area to a lesser extent with electronic circuitry of the display device 110 than in the second display region 112. For example, less electronic circuitry of the display device may be arranged in the first display region 111 compared to the second display region 112. Alternatively or additionally, electronic circuitry of a smaller form factor may be arranged in the first display region 111 compared to the second display region 112. 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 110 is covered in the first display region 111 per unit area to a lesser extent with LEDs than in the second display region 112. In other examples, a resolution of the display may be reduced in the first display region 111 compared to the second display region 112 such that less electronic circuitry (e.g. less LEDs) is provided per unit area on the substrate for the first display region 111 than for the second display region 112. In other words, single light emitting devices/pixels or sets of light emitting devices/pixels may be omitted in the first display region 111 compared to the second display region 112.
In other examples, the arrangement of the light emitting devices/pixels may be altered in the first display region 111 compared to the second display region 112. Additionally or alternatively, the circuit layout of the light emitting devices/pixels may be altered in the first display region 111 compared to the second display region 112.
However, it is to be noted that the above examples for increasing the transparency for the light 121 in the first display region 111 compared to the second display region 112 are not limiting the proposed architecture. Also other designs of the display device may provide increased transparency for the light 121 in the first display region 111.
In order to make use of the non-uniform transmissivity of the display device 110 for the light 121, the electronic device 100 comprises at least one optical element (device) 130 arranged between the at least one illumination element 120 and the display device 110. The at least one optical element 130 is configured to focus the light 121 emitted by the at least one illumination element 120 through the first display region 111 such that the light 121 transmits (passes) through the first display region 111 rather than through the second display region 112. In other words, at least one optical element 130 is configured to direct the light 121 emitted by the at least one illumination element 120 towards the first display region 111 such that a light density of the light 121 transmitting through the first display region 111 is higher than a light density of the light 121 transmitting through the second display region 112. In the example of
As illustrated in
As the light 121 is focused through a region of the display 110 with increased transparency for the light 121, a higher fraction of the light 121 can transmit through the display device 110. Accordingly, a power of the light 121 may be reduced compared to conventional under-display illumination structures. As a consequence, a power consumption of the at least one illumination element 120 may be reduced compared to conventional under-display illumination structures. Further, heating of the display 110 via the light 121 and, hence, an expansion of the display device 110 may be reduced. Therefore, the likelihood of a display damage (e.g. glass fracture) may be reduced.
Although not explicitly illustrated in
In other words, an (e.g. infrared) illumination unit 120 is located behind a display device 110 according to the proposed technique. The (e.g. typically) narrow beam of the illumination unit 120 is directed at a focusing element 130, which is located rather close to the display device 110. As described above, display devices typically do not have a homogenous transparency. As a consequence, the focusing element 130 focuses the light beam onto an area of the display device 110 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
For example, the optical sensor 140 may be a Time-of-Flight (ToF) sensor. The optical sensor 140 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 140 may be part of distance measuring device (e.g. a single pixel ToF camera for auto focus adjustment). Accordingly, the optical sensor 140 may comprise processing circuitry configured to determine, based on the measured reflected light from the scene, 190 at least one of an image of at least part of the scene 190 or a distance of the electronic device 110 to at least one object (such as the head 191) in the scene 190.
The measurements of the optical sensor 140 may further be used for controlling the operation of the at least one illumination element 120. For example, the electronic device may further comprise control circuitry 150 configured to receive an output signal 141 of the optical sensor 140. The output signal 141 indicates an intensity of the reflected light measured by the optical sensor 140. Accordingly, the control circuitry 150 may be further configured to control a light emission intensity of the at least one illumination element 120 based on the output signal 141. In other words, the at least one illumination element 120 may be controlled based on the received signal strength of the optical sensor 140 (which may, e.g., be part of a camera). For example, the above control technique may allow to give dark objects in the scene 190 more light.
Although not illustrated in
In the example of
In the example of
A respective optical element 130-1, 130-2 is arranged between each of the two illumination elements 120-1, 120-2 and the display device 110 for focusing the light 121-1, 121-2 emitted by the respective illumination element 120-1, 120-2 through the first display region. In particular, the optical elements 130-1, 130-2 focus the light 121-1, 121-2 emitted by the respective illumination element 120-1, 120-2 through the two sub-regions 111-1 and 111-2 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 120-1, 120-2 and the display device 110 for focusing the light 121-1, 121-2 emitted by the respective illumination element 120-1, 120-2 through the first display region. For example, two optical elements may be arranged between the illumination element 120-1 and the display device 110 for focusing the light 121-1 emitted by the illumination element 120-1 through the sub-region 111-1 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
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 120-1 and 120-2 may be controlled commonly or individually by the control circuitry 150. For example, the control circuitry 150 may be configured to selectively control light emission by individual ones of the illumination elements 120-1 and 120-2 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 150 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 190 or at least part thereof. For example, the target illumination characteristic may define one or more parts of the scene 190 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 190.
For example, the control circuitry 150 may be configured to receive object information indicating a position or a movement of an object such as the head 191 in the scene 190. Further, the control circuitry 150 may be configured to determine a part of the scene 190 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 191 is in the upper part of the scene 190, the control circuitry 150 may determine that the upper part of the scene 190 likely contains the head. Accordingly, the control circuitry 150 may, e.g., only activate the illumination element 121-1 in order to illuminate the upper part of the scene 190 that likely contains the head 191. The object information may, e.g., be provided by a tracking application executed on the electronic device 200 or a sensor of the electronic device 200.
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
Further, the electronic device 300 comprises a plurality of optical elements arranged between each of the plurality of illumination elements and the display device 110 for focusing the light emitted by the respective illumination element through the first display region of the display device 110. 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 130 in
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 340 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 190.
For example, if the control circuitry 150 that controls the plurality of illumination elements receives object information indicating a position or a movement of the head 191 in the scene 190. The control circuitry 150 determines a part of the scene 191 that likely contains the head 191 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 190 that likely contains the head. Based on updated object information, the shape of the light beam 340 may be continuously changed (adjusted) such that the light beam 340 follows the movement of the head 191. 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,
The method 400 comprises emitting 402 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 400 further comprises focusing 404 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 400, a higher fraction of the light can transmit through the display device compared to conventional approaches.
More details and aspects of the method 400 are explained in connection with the proposed technique or one or more examples described above (e.g.
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.
According to some examples, the electronic device comprises a plurality of illumination elements.
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.
The aspects and features described in relation to a particular one of the previous examples may also be combined with one or more of the further examples to replace an identical or similar feature of that further example or to additionally introduce the features into the further example.
It is further understood that the disclosure of several steps, processes, operations or functions disclosed in the description or claims shall not be construed to imply that these operations are necessarily dependent on the order described, unless explicitly stated in the individual case or necessary for technical reasons. Therefore, the previous description does not limit the execution of several steps or functions to a certain order. Furthermore, in further examples, a single step, function, process or operation may include and/or be broken up into several sub-steps, -functions, -processes or -operations.
If some aspects have been described in relation to a device or system, these aspects should also be understood as a description of the corresponding method. For example, a block, device or functional aspect of the device or system may correspond to a feature, such as a method step, of the corresponding method. Accordingly, aspects described in relation to a method shall also be understood as a description of a corresponding block, a corresponding element, a property or a functional feature of a corresponding device or a corresponding system.
The following claims are hereby incorporated in the detailed description, wherein each claim may stand on its own as a separate example. It should also be noted that although in the claims a dependent claim refers to a particular combination with one or more other claims, other examples may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are hereby explicitly proposed, unless it is stated in the individual case that a particular combination is not intended. Furthermore, features of a claim should also be included for any other independent claim, even if that claim is not directly defined as dependent on that other independent claim.
Number | Date | Country | Kind |
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20207116.3 | Nov 2020 | EP | regional |