WO2025078071A1

WO2025078071A1 - Illumination and sensing unit, display and control device and method for operating a display and control device

Info

Publication number: WO2025078071A1
Application number: PCT/EP2024/074152
Authority: WO
Inventors: Ho Hoai Duc Nguyen; Alexander WANDERER
Original assignee: Ams Osram International GmbH
Current assignee: Ams Osram International GmbH
Priority date: 2023-10-09
Filing date: 2024-08-29
Publication date: 2025-04-17
Anticipated expiration: 2026-04-09

Abstract

An illumination and sensing unit (1) comprising the following features is provided. - a first plurality of light emitting diode chips (2) configured for emitting visible light during operation, - a second plurality of light emitting diode chips (3, 3', 3'') operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range. Further, a display and control device and a method for operating a display and control device are provided.

Description

ILLUMINATION AND SENS ING UNIT , DISPLAY AND CONTROL DEVICE AND METHOD FOR OPERATING A DISPLAY AND CONTROL DEVICE

An illumination and sensing unit , a display and control device and a method for operating a display and control device are provided .

A simpli fied illumination and sensing unit , particularly used as a light source in a display and control device , and a display and control device are to be provided . Furthermore , a simpli fied method for operating a display and control device is to be provided .

These obj ects are achieved by an illumination and sensing unit with the features of claim 1 , a display and control device with the features of claim 6 , and a method for operating a display and control device with the steps of claim 9 .

Improved embodiments and developments of the illumination and sensing unit , the display and control device and the method for operating a display and control device are given in the respective dependent claims .

According to an embodiment , the illumination and sensing unit comprises a first plurality of light emitting diode chips ( short : LED chip ) configured for emitting visible light during operation . Particularly, the light emitting diode chips of the first plurality of light emitting diode chips emit visible light during operation . Particularly, the first plurality of light emitting diode chips are configured to provide an illumination function of the illumination and sensing unit . For example , the light emitting diode chips of the first plurality of light emitting diode chips emit the visible light to one or two directions . Particularly, a first number of the light emitting diode chips of the first plurality of light emitting diode chips emit red light , a second number of the light emitting diode chips of the first plurality of light emitting diode chips emit green light and a third number of light emitting diode chips of the first plurality of light emitting diode chips emit blue light .

According to a further embodiment , the illumination and sensing unit comprises a second plurality of light emitting diode chips operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range . Particularly, a first number of the light emitting diode chips of the second plurality of light emitting diode chips emit electromagnetic radiation of the first wavelength range during operation and a second number of the light emitting diode chips of the second plurality of light emitting diode chips are operated to detect the electromagnetic radiation of the first wavelength range . Particularly, it depends on an operation mode whether the light emitting diode chips of the second plurality of light emitting diode chips emit or detect electromagnetic radiation of the first wavelength range during operation .

Particularly, the illumination and sensing unit comprises the first plurality of light emitting diode chips configured for emitting visible light during operation and the second plurality of light emitting diode chips operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range .

For example , each light emitting diode chip comprises an epitaxial semiconductor layer stack with an active zone emitting or detecting electromagnetic radiation during operation . For the generation of electromagnetic radiation or the detection of electromagnetic radiation, the active zone comprises a pn-j unction . I f a forward current is applied to the pn-j unction, the pn-j unction generates electromagnetic radiation and i f a reverse current is applied to the pn- j unction, the pn-j unction is operated to detect electromagnetic radiation . Particularly, the light emitting diode chips of the first number of the second plurality of light emitting diode chips are driven in a forward direction by applying a forward current such that they emit electromagnetic radiation of the first wavelength range , while the light emitting diode chips of the second number of the second plurality of light emitting diode chips are driven in a reverse direction by applying a reverse current such that they detect incident electromagnetic radiation of the first wavelength range . In other words , the light emitting diode chips of the second number of the second plurality of light emitting diode chips are operated as photodiodes in order to detect electromagnetic radiation of the first wavelength range .

The illumination and sensing unit is based on the idea to use the light emitting diode chips of the first plurality of light emitting diode chips for illumination and the light emitting diode chips of the second plurality of light emitting diode chips for sensing . For example , the light emitting diode chips of the first plurality of light emitting diode chips form pixels , while with the light emitting diode chips of the second plurality of light emitting diode chips a pressure , for example due to a touch event triggered by a human user, is detected . Particularly, the light emitting diode chips of the second plurality of light emitting diode chips are all equal and it is determined by the direction of the applied current , whether the light emitting diode chip emits or is configured to detect electromagnetic radiation of the first wavelength range .

For example , the epitaxial semiconductor layer stack of the light emitting diode chips comprises or consists of an I I I /V compound semiconductor material , such as an arsenide semiconductor compound material , a phosphide semiconductor compound material or a nitride compound semiconductor material .

Arsenide semiconductor compound materials are semiconductor compound materials containing arsenic, such as the materials from the system In_xAl_yGai-_x-yAs with 0 < x < 1 , 0 < y < 1 and x+y < 1 . Particularly, epitaxial semiconductor layer stacks comprising or consisting of an arsenide compound semiconductor material emit or detect electromagnetic radiation from the infrared to red spectral range .

Phosphide semiconductor compound materials are compound semiconductor materials containing phosphorus , such as the materials from the system In_xAl_yGai-_x-yP with 0 < x < 1 , 0 < y < 1 and x+y < 1 . Particularly, epitaxial semiconductor layer stacks comprising or consisting of a phosphide semiconductor compound material emit or detect electromagnetic radiation from the red to green spectral range . Nitride semiconductor compound materials are semiconductor compound materials containing nitrogen, such as the materials from the system In_xAl_yGai-_x-yN with 0 < x < 1 , 0 < y < 1 and x+y < 1 . Particularly, epitaxial semiconductor layer stacks comprising or consisting of a nitride semiconductor compound material emit or detect electromagnetic radiation from blue to ultraviolet spectral range .

The light emitting diode chips have a radiation transmission surface from which electromagnetic radiation is emitted, i f the active zone generates electromagnetic radiation and through which electromagnetic radiation penetrates into the light emitting diode chip, i f the active zone detects electromagnetic radiation .

According to a further embodiment of the illumination and sensing unit , some or all of the light emitting diode chips are micro-LEDs .

As a broad definition, a micro-LED could be seen as any light emitting diode ( LED) - generally not a laser - with a particularly small si ze .

As a rule - and this is a very important criterion in addition to the si ze - a growth substrate of the epitaxial layer stack is removed from the micro-LEDs , so that typical thicknesses of such micro-LEDs are between 1 . 5 micrometer and 10 micrometer, limits included, for example . Also , the micro- LED is particularly free of a carrier for mechanical stabili zation .

In principle , a micro-LED does not necessarily have to have a rectangular radiation transmission surface . Generally, for example , an LED could have a radiation transmission surface in which, in plan view of the epitaxial semiconductor layers of the epitaxial semiconductor layer stack, any lateral extent of the radiation transmission surface is less than or equal to 100 micrometer or less than or equal to 70 micrometer or less than or equal to 10 micrometer .

For example , in the case of an rectangular micro-LED, an edge length - especially in plan view on the epitaxial semiconductor layers of the epitaxial semiconductor layer stack - being smaller than or equal to 70 micrometer or smaller than or equal to 50 micrometer is often cited as a criterion .

Mostly, such micro-LEDs are provided on wafers with - for the micro-LEDs non-destructively - detachable holding structures .

Currently, micro-LEDs are often used in displays . The micro- LEDs form pixels or subpixels and emit visible light of a defined color . Small pixel si ze and a high density with close distances make micro-LEDs suitable , among others , for small monolithic displays for augmented reality applications , especially data glasses . In addition, other applications are being developed, in particular regarding the use in data communication or pixelated lighting applications .

Di f ferent ways of spelling micro-LED, e . g . pLED, p-LED, uLED, u-LED or micro light emitting diode can be found in the relevant literature .

According to a further embodiment of the illumination and sensing unit , some or all of the light emitting diode chips are flip-chips . Particularly, the radiation transmission surface of the flip-chip is free of electrical contacts . For example , the electrical contacts of the flip-chips are arranged at a common face of the flip-chip .

According to a further embodiment of the illumination and sensing unit , the light emitting diode chips are partially or completely embedded in a plastic foil . I f the light emitting diode chips are only partially embedded in the plastic foil , the radiation transmission surfaces of the first plurality of light emitting diode chips and/or the radiation transmission surfaces of the second plurality of light emitting diode chips are freely accessible , for example . Particularly, the plastic foil is flexible such that the illumination and sensing unit is also flexible . For example , all light emitting diode chips of the illumination and sensing unit are at least partially embedded in the plastic foil . The light emitting diode chips are particularly arranged laterally to each other within the plastic foil and at a distance to each other .

Particularly, the plastic foil is transparent at least for visible light emitted by the light emitting diode chips of the first plurality of light emitting diode chips and/or for the electromagnetic radiation of the first wavelength range emitted and/or detected by the light emitting diode chips of the second plurality of light emitting diode chips . In this context , the term "transparent" means particularly that at least 80% or at least 85% or at least 90% of the visible light and/or the electromagnetic radiation of the first wavelength range is transmitted by the plastic foil . For example , the plastic foil comprises or consists of poly ( ethylene therephthalate ) ( PET ) or polycarbonate ( PC ) . For example , the light emitting diode chips are glued to the plastic foil .

For example , metallic conductor tracks are comprised by the plastic foil for electrically connecting the light emitting diode chips .

According to a further embodiment of the illumination and sensing unit , the light emitting diode chips of the second plurality of light emitting diode chips are operable to emit infrared electromagnetic radiation or to detect infrared electromagnetic radiation . In other words , the first wavelength range consists of wavelengths within the infrared spectral range .

The illumination and sensing unit described so far is particularly intended and configured to be part of a display and control device . Particularly, the illumination and sensing unit is a light source as well as a sensing part of the display and control device . All features and embodiments described in connection with the illumination and sensing unit can also be embodied within the display and control device and vice versa .

For example , the display and control device is part of a touch screen or forms a touch screen for example for controlling di f ferent external devices of a motor vehicle , such as an entertainment device or a ventilation device . The touch screen is configured to detect touch events of a human user, for example triggered by application of a pressure by a finger of the human user . The light emitting diode chips of the first plurality of light emitting diode chips are , for example , used as illumination for displaying icons , while the light emitting diode chips of the second plurality of light emitting diode chips are used for detecting the touch events .

According to an embodiment , the display and control device comprises a deflectable smart surface layer . Particularly, the deflectable smart surface layer is deflectable by the touch of the finger of the human user . For example , the deflectable smart surface layer comprises several single layers , such as a plastic layer and a glass layer . For example , the glass layer forms an outer surface of the display and control device .

According to a further embodiment , the display and control device comprises an illumination and sensing unit as already described . Particularly, the display and control device comprises a first plurality of light emitting diode chips configured for emitting visible light during operation and a second plurality of light emitting diode chips operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range during operation .

According to a further embodiment of the display and control device , the visible light of the first plurality of light emitting diode chips illuminates the deflectable smart surface layer during operation . Particularly, the visible light emitted by the light emitting diode chips of the first plurality of light emitting diode chips transmits the deflectable smart surface layer .

For example , the light emitting diode chips of the first plurality of light emitting diode chips emit red light , green light or blue light during operation in order to form subpixels of pixels of the display and control device for depicting icons , symbols and/or text . For example , a first number of the first plurality of light emitting diode chips emit red light during operation, a second number of the first plurality of light emitting diode chips emit green light during operation, and a third number of the first plurality of light emitting diode chips emit blue light during operation .

The deflectable smart surface layer is particularly preferably transparent for the visible light emitted by the first plurality of light emitting diode chips . In this context , the term "transparent" means particularly that at least 80% or at least 85% or at least 90% of the visible light is transmitted by the deflectable smart surface layer .

According to a further embodiment of the display and control device , electromagnetic radiation of the first wavelength range emitted by light emitting diode chips of the second plurality of light emitting diode chips is reflected at the deflectable smart surface layer and detected by light emitting diode chips of the second plurality of light emitting diode chips . Particularly preferably, the electromagnetic radiation of the first wavelength range is specularly reflected at the deflectable smart surface layer .

It is not necessarily the case that the electromagnetic radiation of the first wavelength range is reflected completely at the deflectable smart surface layer . Rather, only a part of the electromagnetic radiation of the first wavelength range emitted by light emitting diode chips of the second plurality of light emitting diode chips is reflected at the deflectable smart surface layer . For example , at most 10 % or at most 4 % of the electromagnetic radiation of the first wavelength range impinging on the deflectable smart surface layer is reflected specularly by the deflectable smart surface layer .

According to a further embodiment of the display and control device , the light emitting diode chips of the second plurality of light emitting diode chips are equal to each other and the light emitting diode chips of the second plurality of light emitting diode chips intended to detect electromagnetic radiation of the first wavelength range is operated in a reverse direction during operation . These light emitting diode chips act as photodiodes during operation . The light emitting diode chips of the second plurality of light emitting diode chips intended to detect electromagnetic radiation of the first wavelength range form a second number of the second plurality of light emitting diode chips .

I f the light emitting diode chips of the second plurality of light emitting diode chips are equal to each other, particularly, epitaxial semiconductor stacks of the light emitting diode chips of the second plurality of light emitting diode chips are equal to each other and have the same semiconductor compound materials .

According to a further embodiment of the display and control device , the light emitting diode chips of the second plurality of light emitting diode chips emitting electromagnetic radiation of the first wavelength range are operated in a forward direction during operation such that the light emitting diode chips emit electromagnetic radiation of the first wavelength range . Particularly, a first number of the light emitting diode chips of the second plurality of light emitting diode chips are operated in a forward direction during operation, emitting electromagnetic radiation of the first wavelength range , while a second number of the light emitting diode chips of the second plurality of light emitting diode chips are operated in a reverse direction and detect electromagnetic radiation of the first wavelength range during operation . The first number of light emitting diode chips and the second number of light emitting diode chips together form the second plurality of light emitting diode chips . Particularly, the detection of the electromagnetic radiation of the first wavelength range is performed by other light emitting diode chips of the second plurality of light emitting diode chips than emission of the electromagnetic radiation of the first wavelength range during operation .

For example , a light emitting diode chip emitting electromagnetic radiation of the first wavelength range is surrounded at least partially by several light emitting diode chips operated to detect electromagnetic radiation of the first wavelength range . The light emitting diode chips particularly detects the electromagnetic radiation of the first wavelength range emitted by the surrounded light emitting diode chip and reflected at the deflectable smart surface layer .

The display and control device described herein is configured to be operated with the method described in the following . Features and embodiments described in connection with the display and control device can also be embodied within the method and vice versa . Particularly the display and control device to be operated with the method comprises a deflectable smart surface layer, a first plurality of light emitting diode chips configured for emitting visible light during operation and a second plurality of light emitting diode chips operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range .

According to an embodiment of the method for operating the display and control device , the first plurality of light emitting diode chips is operated such that visible light of the first plurality of light emitting diode chips illuminates the deflectable smart surface layer . In other words , the first plurality of light emitting diode chips emits visible light that illuminates the deflectable smart surface layer during operation .

According to a further embodiment of the method, light emitting diode chips of the second plurality of light emitting diode chips are operated such that electromagnetic radiation emitted by light emitting diode chips of the second plurality of the light emitting diode chips is reflected at the deflectable smart surface layer and detected by at least one light emitting diode chip of the second plurality of light emitting diode chips such that an electrical signal is produced . Particularly, the electrical signal is produced by the light emitting diode chips detecting the reflected electromagnetic radiation of the first wavelength range . For example , the electrical signal is an electrical current signal or an electrical voltage signal . Particularly, the electromagnetic radiation of the first wavelength range is emitted by other light emitting diode chips of the second plurality of light emitting diode chips than detected .

Particularly, the method for operating a display and control device comprising the deflectable smart surface layer, the first plurality of light emitting diode chips configured for emitting visible light during operation, and the second plurality of light emitting diode chips operable to emit electromagnetic radiation of the first wavelength range or to detect electromagnetic radiation of the first wavelength range , comprises the steps :

- operating the first plurality of light emitting diode chips such that visible light of the first plurality of light emitting diode chips illuminates the deflectable smart surface layer,

- operating light emitting diode chips of the second plurality of light emitting diode chips such that electromagnetic radiation emitted by light emitting diode chips of the second plurality of light emitting diode chips is reflected at the deflectable smart surface layer and detected by at least one light emitting diode chip of the second plurality of light emitting diode chips such that an electrical signal is produced .

According to a further embodiment of the method, the electrical signal of the at least one light emitting diode chip detecting the electromagnetic radiation of the first wavelength range is increased when the deflectable smart surface layer is deflected . Particularly, during deflection a distance between at least one of the light emitting diode chips of the second plurality of light emitting diode chips is decreased such that the amount of reflected electromagnetic radiation of the first wavelength range detected by the at least one light emitting diode chip of the second plurality of light emitting diode chips detecting the electromagnetic radiation of the first wavelength range increases .

According to a further embodiment of the method, the electrical signal is enhanced when a pressure on the deflectable smart surface layer is enhanced . For example , the pressure on the deflectable smart surface layer is applied by a human user . By enhancing the pressure on the deflectable smart surface layer the deflection of the deflectable smart surface layer is enhanced and the distance between the at least one light emitting diode chip of the second plurality of light emitting diode chips detecting the electromagnetic radiation of the first wavelength range and the deflectable smart surface layer is decreased .

According to a further embodiment of the method, the display and control device generates a control signal when the electrical signal exceeds a predetermined threshold . In such a way, the control signal is only generated, i f the human user intends to create a touch event and not by accident . The control signal is particularly configured to control an external device , for example being part of a motor vehicle . For example , the control signal is configured to control a ventilation device , a lighting device or an entertainment device of the motor vehicle .

According to a further embodiment of the method, the second number of light emitting diode chips of the second plurality of light emitting diode chips detecting the electromagnetic radiation of the first wavelength range is increased when the value of the electrical signal exceeds the threshold and the deflection of the deflectable smart surface layer is increased further . When the deflection of the deflectable smart surface layer is increased, the reflected electromagnetic radiation of the first wavelength range impinges on an enhanced number of light emitting diode chips of the second plurality of light emitting diode chips operated for detection . In such a way, the electrical signal is enhanced and a further deflection of the deflectable smart surface layer is detected .

When the deflectable smart surface layer of the display and control device is deflected, for example , by a pressure applied by an external human user, the deflectable smart surface reduces its distance to the light emitting diode chips of the second plurality of light emitting diode chips such that the electrical signal generated by the detecting light emitting diode chips of the second plurality of light emitting diode chips is enhanced . When the pressure is increased and the distance is decreased further, the electrical signal is increased further, since the reflected electromagnetic radiation of the first wavelength range reaches an increased number of detecting light emitting diode chips of the second plurality of light emitting diode chips . In such a way, an increased number of light emitting diode chips of the second plurality of light emitting diode chips acting as photodetectors are triggered when the human user presses harder with the finger during a touch event .

According to a further embodiment of the method, the light emitting diode chips of the second plurality of light emitting diode chips operated to detect the electromagnetic radiation of the first wavelength range are controlled separately from the light emitting diode chips of the second plurality of the light emitting diode chips emitting the electromagnetic radiation of the first wavelength range and/or the light emitting diode chips emitting visible light . Particularly, the light emitting diode chips of the second plurality of light emitting diode chips operated to detect the electromagnetic radiation of the first wavelength range are read out separately from the light emitting diode chips of the second plurality of light emitting diode chips emitting the electromagnetic radiation of the first wavelength range . For example , two di f ferent driver units are used to control the light emitting diode chips of the second plurality of light emitting diode chips emitting the electromagnetic radiation of the first wavelength range and the light emitting diode chips of the second plurality of light emitting diode chips operated to detect the electromagnetic radiation of the first wavelength range .

According to a further embodiment of the method, at least two segments of the display and control device are controlled independently of each other . Particularly, each segment corresponds to a di f ferent external device to be controlled by the display and control device . In other words , each segment produces a di f ferent control signal in order to control di f ferent external devices , for example of a motor vehicle . For example , in each segment a di f ferent icon illuminated by the light emitting diode chips of the first plurality of light emitting diode chips is shown .

Further advantageous embodiments and developments of the illumination and sensing unit , the display and control device and the method for operating a display and control device result from the exemplary embodiment described below in connection with the Figures . Figure 1 shows schematically a plan view of an illumination and sensing unit according to an exemplary embodiment .

Figure 2 shows schematically a sectional view of an illumination and sensing unit according to an exemplary embodiment .

Figures 3 and 4 show schematically a display and control device according to two di f ferent exemplary embodiments .

Figures 5 and 6 show schematically di f ferent circuit diagrams of an electrical connection of a light emitting diode chip of the second plurality of light emitting diode chips .

Figures 7 to 9 show schematically stages of a method for operating a display and control device according to an exemplary embodiment .

Figures 10 to 12 show schematically a display and control device according to several exemplary embodiments .

Equal or similar elements as well as elements of equal function are designated with the same reference signs in the Figures . The Figures and the proportions of the elements shown in the Figures are not regarded as being shown to scale . Rather, single elements , in particular layers , can be shown exaggerated in magnitude for the sake of better presentation and/or better understanding .

The illumination and sensing unit 1 according to the exemplary embodiment of Figures 1 and 2 comprises a first plurality of light emitting diode chips 2 configured to emit visible light during operation . At present , the light emitting diode chips 2 of the first plurality of light emitting diode chips have radiation transmission surfaces 5 with three subpixels R, G, B, wherein one subpixel R emits red light , one subpixel G emits green light and one subpixel B emits blue light during operation . As an alternative , it is possible that each subpixel R, G, B is formed by a separate light emitting diode chip .

Further, the illumination and sensing unit 1 according to the exemplary embodiment of Figures 1 and 2 comprises a second plurality of light emitting diode chips 3 . The light emitting diode chips 3 of the second plurality of light emitting diode chips 3 have a first number of light emitting diode chips 3 ' emitting electromagnetic radiation of a first wavelength range during operation . Particularly, the first number of the second plurality of light emitting diode chips 3 ' emits infrared light during operation . A second number of the second plurality of the light emitting diode chips 3 ' ’ is operated to detect the electromagnetic radiation of the first wavelength range , at present the infrared light emitted by the first number of light emitting diode chips 3 ' of the second plurality of light emitting diode chips 3 .

As can be seen in Figure 1 , one light emitting diode chip 3 ' of the first number of the second plurality of light emitting diode chips emitting electromagnetic radiation of the first wavelength range is surrounded by several light emitting diode chips 3 ' ’ of the second number of the second plurality of light emitting diode chips 3 operated to detect electromagnetic radiation of the first wavelength range . As can be seen in Figure 2 , the light emitting diode chips 2 , 3 , of the illumination and sensing unit 1 are electrically conductively connected to metallic conductor tracks 4 comprising or consisting of copper, for example . Further, the light emitting chips 3 ' of the first number of the second plurality of light emitting diode chips 3 are electrically conductively connected to a driver unit driving the light emitting diode chips 3 ' of the first number of the second plurality of light emitting diode chips 3 in a forward direction by applying a forward current such that they emit the electromagnetic radiation of the first wavelength range during operation . A respective circuit diagram is exemplarily shown in Figure 5 .

The light emitting chips 3 ' ’ of the second number of the second plurality of light emitting diode chips 3 are electrically conductively connected to a further driver unit driving the light emitting diode chips 3 ' ’ of the second number of the second plurality of light emitting diode chips 3 in a reverse direction by applying a reverse current such that they are operated to detect the electromagnetic radiation of the first wavelength range during operation . A respective circuit diagram is exemplarily shown in Figure 6 .

Also , the light emitting chips 2 of the first plurality of light emitting diode chips 2 are electrically conductively connected to a further driver unit driving the light emitting diode chips 2 of the first plurality of light emitting diode chips 2 in a forward direction such that they emit visible light during operation . The driver units are not shown in the Figure for the sake of clear arrangement . The driver unit can be part of the illumination and sensing unit 1 or of the display and control device described later on comprising the illumination and sensing unit 1 .

For example , as shown in Figure 2 , the light emitting semiconductor chips are embedded in a plastic foil 6 being transparent and flexible . Also , the illumination and sensing unit 1 according to the exemplary embodiment of Figures 1 and 2 is transparent and flexible .

The display and control device according to the exemplary embodiment of Figure 3 comprises an illumination and sensing unit 1 as for example already described in connection with Figures 1 and 2 . The illumination and sensing unit 1 is laminated on each side with a glass layer 7 and a polymer layer 8 . Particularly, one of the glass layer 7 and the polymer layer 8 form a deflectable smart surface layer 9 of the display and control device at one side of the display and control device . For example , the polymer layer 8 comprises or consists of polyvinyl butyral ( PVB ) . As exemplarily shown in Figure 3 , it is possible that the light emitting diode chips 2 of the first plurality of light emitting diode chips of the illumination and sensing unit 1 emit visible light in one or two directions .

The display and control device according to the exemplary embodiment of Figure 4 has a deflectable smart surface layer 9 . For example , the deflectable smart surface layer 9 comprises a polymer layer 8 and a glass layer 7 as explained in connection with Figure 3 . Particularly, the deflectable smart surface layer 9 is configured to be deflected by the pressure of a finger 10 of a human user in order to trigger a touch event 11 . During the touch event 11 the human user presses with the finger 10 on the deflectable smart surface layer 9 and deflects the deflectable smart surface layer 9 on a laterally limited touch area ( see also Figures 7 and 8 ) .

Further, an illumination and sensing unit 1 as already described in connection with Figures 1 and 2 is comprised by the display and control device according to Figure 4 .

The light emitting diode chips 2 , 3 of the illumination and sensing unit 1 are arranged on metallic conductor tracks 4 for electrical connection . Particularly, a first plurality of light emitting diode chips 2 of the illumination and sensing unit 1 , a first number 3 ' of a second plurality of light emitting diode chips 3 and a second number 3 ' ’ of the second plurality of light emitting diode chips 3 are connected to di f ferent driving units in order to be operated separately from each other (not shown) .

The light emitting diode chips 2 , 3 of the illumination and sensing unit 1 of the display and control device of Figure 4 are embedded in transparent and flexible plastic foil 6 . For example , metallic conductor tracks 4 are arranged at a back side surface of the plastic foil 6 . It is also possible that the metallic conductor tracks 4 are a embedded within the plastic foil 6 as described in connection with Figure 3 .

Further, the display and control device according to the exemplary embodiment of Figure 4 comprises a flexible layer, for example the polymer layer 8 as shown in Figure 3 . Further, there is a glass substrate comprised by the display and control device of Figure 4 . The flexible layer 12 and the glass substrate 7 are laminated to the illumination and sensing unit 1 . Figure 5 exemplarily shows a circuit diagram for operating a light emitting diode chip 2 , 3 ' of the illumination and sensing unit in an emitting operation mode . The light emitting diode chip 2 , 3 ' has a pn-j unction 13 configured to emit or to detect electromagnetic radiation .

According to the emitting operation mode the light emitting diode chip 2 , 3 ' is operated in a forward direction and a current is applied in a forward direction to the pn-j unction 13 such that the light emitting diode chip 2 , 3 ' emits electromagnetic radiation, for example visible light or electromagnetic radiation of the first wavelength range .

Figure 6 exemplarily shows a further circuit diagram for operating light emitting diode chips 3 ' ’ of the illumination and sensing unit 1 in a detecting operation mode . The light emitting diode chip 3 ' ’ has a pn-j unction 13 configured to emit or to detect electromagnetic radiation .

According to the detecting operation mode the light emitting diode chip 3 ' is operated in a reverse direction and a current is applied in a reverse direction to the pn-j unction 13 such that the light emitting diode chip 3 ' ’ is operated to detect electromagnetic radiation, for example electromagnetic radiation of the first wavelength range . During the detection operation mode , the pn-j unction 13 of the light emitting diode chip 3 ' ’ converts incident electromagnetic radiation of the first wavelength range in electrical current as an electrical signal . In other words , in the detecting operation mode , the light emitting diode chip 3 ' ’ acts as a photodiode . For example , the electrical signal produced by the light emitting diode chip 3 ' ' operated in the detection operation mode is forwarded to an ampli fier 14 .

During the method according to the exemplary embodiment of Figures 7 to 9 , a display and control device as for example already described in connection with Figures 3 or 4 is operated .

During the method for operating a display and control device , a first plurality of light emitting diode chips 2 are driven in an emitting operation mode such that they emit visible light in order to provide a display function .

During the method for operating a display and control device , a first number of a second plurality of light emitting diode chips 3 ' are driven in an emitting operation mode such that they emit electromagnetic radiation of a first wavelength range , for example infrared light .

The electromagnetic radiation of the first wavelength range emitted by the light emitting diode chips 3 ' of the first number of the second plurality of light emitting diode chips 3 impinges on a deflectable smart surface layer 9 and is specularly reflected by the deflectable smart surface layer 9 to an illumination and sensing unit 1 of the display and control device . The light emitting diode chips 3 ' ’ of the second number of the second plurality of light emitting diode chips 3 are operated in a detecting operation mode and detect electromagnetic radiation of the first wavelength range specularly reflected by the deflectable smart surface layer 9 such that an electrical signal is generated . In the case that a human user intends to generate a touch event in order to amend a setup of an external device to be controlled by the display and control device , a finger 10 of the human user approaches the deflectable smart surface layer 9 until the finger 10 touches the deflectable smart surface layer 9 and deflects the deflectable smart surface layer 9 by application of a pressure ( Figures 7 and 9 ) . During this process , the electrical signal increases , first due the shadow of the finger 10 above the deflectable smart surface layer 9 and, when the pressure is applied, due to a decreasing distance between the deflectable smart surface layer 9 and the light emitting diode chips 3 ' ’ of the second number of the second plurality of light emitting diode chips 3 .

In order to distinguish between random approaches and/or random touches of the human user, a control signal is only generated, i f the electrical signal exceeds a predetermined threshold . The control signal is generated by the display and control device and sent to the external device for changing its setup .

Further, i f the pressure of the finger 10 is enhanced, the second number of the second plurality of light emitting diode chips 3 ' ’ detecting electromagnetic radiation of the first wavelength range is enhanced such that the electric signal is enhanced and the control signal is adapted accordingly ( Figures 8 and 9 ) . In such a way, a volume of an entertainment device can be adapted, for example , by the display and control device .

The display and control devices according to the exemplary embodiments of Figures 10 and 11 both have segments 15 , which can be controlled independently of each other. For example, each segment 15 corresponds to a different external device to be controlled by the display and control device. As for example shown in Figure 11, different segments 15' of the display and control device can be switched on simultaneously while other segments 15' ’ are switched off.

As for example shown in Figure 12, each segment 15 corresponds to a different external device to be controlled by the display and control device, for example. Further, each segment 15 can be provided with an illuminated icon 16 illuminated by the light emitting diode chips 2 of the first plurality of light emitting diode chips. Further, an illuminated area 17 to display text can be provided.

The present application claims priority of the German application DE 102023127450.3, the disclosure content of which is incorporated herein by reference.

The invention is not limited to the description of the exemplary embodiments. Rather, the invention comprises each new feature as well as each combination of features, particularly each combination of features of the claims, even if the feature or the combination of features itself is not explicitly given in the claims or the exemplary embodiments.

References

1 illumination and sensing unit

2 first plurality of light emitting diode chips

3 second plurality of light emitting diode chips

3 ' light emitting diode chips emitting electromagnetic radiation of the first wavelength

3 ' ’ light emitting diode chips operated to detect electromagnetic radiation of the first wavelength

4 metallic conductor track

5 radiation transmission surface

6 plastic foil

7 glass layer

8 polymer layer

9 deflectable smart surface layer

10 finger

11 touch event

12 flexible layer

13 pn-j unction

14 amp 1 i f i e r

15 segments

15 ' segment being switched on

15 ' ’ segment being switched of f

16 icon

17 illuminated area to display text

R, G, B subpixel

Claims

1. Method for operating a display and control device comprising

- a deflectable smart surface layer (9) ,

- a first plurality of light emitting diode chips (2) configured for emitting visible light during operation,

- a second plurality of light emitting diode chips (3, 3' , 3' ’ ) operable to emit electromagnetic radiation of a first wavelength range or to detect electromagnetic radiation of the first wavelength range, wherein the method comprises the steps:

- operating the first plurality of light emitting diode chips (2) such that visible light of the first plurality of light emitting diode chips (2) illuminates the deflectable smart surface layer (9) ,

- operating light emitting diode chips (3' ) of the second plurality of light emitting diode chips (3) such that electromagnetic radiation of the first wavelength range emitted by light emitting diode chips (3' ) of the second plurality of light emitting diode chips (3) is reflected at the deflectable smart surface layer (9) and detected by at least one light emitting diode chip (3' ' ) of the second plurality of light emitting diode chips (3) such that an electrical signal is produced, wherein the electrical signal is enhanced, if a pressure on the deflectable smart surface layer (9) is enhanced.

2. Method according to the previous claim, wherein the electrical signal of the at least one light emitting diode chip (3' ' ) detecting the electromagnetic radiation of the first wavelength range is increased, if the deflectable smart surface layer (9) is deflected.

3. Method according to any of the previous claims, wherein the display and control device generates a control signal, if the electrical signal exceeds a predetermined threshold.

4. Method according to any of the previous claims, wherein the number of light emitting diode chips (3^{, f} ) of the second plurality of light emitting diode chips detecting the electromagnetic radiation of the first wavelength range is increased, if the value of the electrical signal exceeds the threshold, and the deflection of the deflectable smart surface layer (9) is increased further.

5. Method according to any of the previous claims, wherein the light emitting diode chips (3^{, f} ) of the second plurality of light emitting diode chips (3) operated to detect the electromagnetic radiation of the first wavelength range are controlled separately from the light emitting diode chips (3' ) of the second plurality of light emitting diode chips (3) emitting the electromagnetic radiation of the first wavelength range.

6. Method according to any of the previous claims, wherein

- at least two segments (15) of the display and control device are independently controlled from each other, and

- each segment (15) corresponds to a different external device to be controlled by the display and control device.

7. Method according to any of the previous claims, wherein some or all of the light emitting diode chips (2, 3, 3' , 3' ’ ) are micro-LEDs.

8. Method according to any of the previous claims, wherein some or all of the light emitting diode chips (2, 3, 3' , 3' ’ ) are flip-chips.

9. Method according to any of the previous claims, wherein the light emitting diode chips (2, 3, 3' , 3' ' ) are at least partially embedded in a plastic foil (6) .

10. Method according to any of the previous claims, wherein the light emitting diode chips (3, 3' ) of the second plurality of light emitting diode chips (3) are operable to emit infrared electromagnetic radiation or to detect infrared electromagnetic radiation.

11. Method according to any the previous claim, wherein

- the light emitting diode chips (3, 3' ) of the second plurality of light emitting diode chips (3) are equal to each other, and

- the light emitting diode chips (3' ' ) of the second plurality of light emitting diode chips (3) detecting electromagnetic radiation of the first wavelength range are operated in a reverse direction during operation.

12. Method according to any of the previous claims, wherein the light emitting diode chips (3' ) of the second plurality of light emitting diode chips (3) emitting electromagnetic radiation of the first wavelength range are operated in a forward direction during operation.