DISPLAY MODULE, SCREEN AND METHOD FOR OPERATING A DISPLAY MODULE

Abstract

A display module includes a carrier with a front face and a rear face. The display module also includes a pixel array. The pixel array includes a plurality of electrically drivable pixels on the front face. In operation, electromagnetic radiation is emitted via each driven pixel. The display module further includes a wiring layer on the front face, via which the pixels are electrically connected to one another. The display module additionally includes a receiving unit on the front face. The receiving unit is electrically connected with the wiring layer. The receiving unit is configured to wirelessly receive a supply energy for the operation of the display module.

Claims

1. A display module comprising a carrier with a front face and a rear face, a pixel array comprising a plurality of electrically drivable pixels on the front face wherein, in operation, electromagnetic radiation is emitted via each driven pixel, a wiring layer on the front face, via which the pixels are electrically connected to one another, and a receiving unit on the front face, wherein the receiving unit is electrically connected with the wiring layer, and the receiving unit is configured to wirelessly receive a supply energy for the operation of the display module.

2. The display module according to claim 1, further comprising a transmitting unit at the rear face, wherein the transmitting unit is configured to transmit the supply energy for the operation of the display module through the carrier to the receiving unit.

3. The display module according to claim 1, wherein the receiving unit is configured to wirelessly receive control signals for individually driving individual pixels.

4. The display module according to claim 1, wherein the receiving unit is configured for inductive and/or capacitive and/or optical wireless reception of supply energy.

5. The display module according to claim 1, wherein the receiving unit comprises at least one coil for inductive, wireless receiving of the supply energy.

6. The display module according to claim 1, wherein the receiving unit comprises at least one electrode for capacitive, wireless reception of the supply energy.

7. The display module according to claim 1, wherein for optical, wireless receiving of the supply energy, the receiving unit comprises at least one photodetector.

8. The display module according to claim 1, wherein the receiving unit comprises a first receiving element and a second receiving element, the first receiving element is configured for wireless reception of the supply power for the display module, and the second receiving element is configured for wireless reception of control signals for the individual control of individual pixels.

9. The display module according to claim 1, wherein the wiring layer and/or the receiving unit are thin-film structures.

10. The display module according to claim 1, comprising an active matrix control system on the front face for individually driving the individual pixels.

11. The display module according to claim 10, wherein the wiring layer comprises thin-film transistors, and at least one thin-film transistor is assigned to each pixel for controlling the pixel.

12. The display module according to claim 10, wherein the display module comprises semiconductor chips on the front face the semiconductor chips are each arranged in the region between two pixels, and the semiconductor chips are configured to control the pixels.

13. A screen comprising a plurality of interconnected display modules each according to claim 1.

14. A method for operating a display module according to claim 1, comprising A) Wirelessly transmitting control signals for individually driving individual pixels and supply power for operating the display module from a transmitting unit through the carrier to the receiving unit, B) Forwarding the control signals and the supply energy from the receiving unit to the pixels via the wiring layer, and C) Driving individual pixels as a function of the control signals and with the aid of the supply energy, wherein electromagnetic radiation is emitted via the driven pixels.

15. The method for operating a display module according to claim 14, wherein steps A) to C) are carried out in alphabetical order.

16. The method for operating a display module according to claim 14, wherein the control signals and/or the supply energy are frequency modulated.

17. A display module comprising a carrier with a front face and a rear face, a pixel array comprising a plurality of electrically drivable pixels on the front face, wherein, in operation, electromagnetic radiation is emitted via each driven pixel, a wiring layer on the front face, via which the pixels are electrically connected to one another, and a receiving unit on the front face, wherein the receiving unit is electrically connected with the wiring layer, the receiving unit is configured to wirelessly receive a supply energy for the operation of the display module, the wiring layer is arranged between the pixels and the carrier, and the receiving unit is arranged between the pixels and the front face.

Description

[0058] Showing in:

[0059] FIGS. 1, 6 and 8 to 11 exemplary embodiments of the display module, each in cross-sectional view,

[0060] FIG. 2 an exemplary embodiment of the screen in plan view,

[0061] FIGS. 3 and 5 sections of an exemplary embodiment of the screen in various sectional views,

[0062] FIG. 4 various exemplary embodiments of coils,

[0063] FIG. 7 a schematic switching arrangement of an exemplary embodiment of the display module.

[0064] FIG. 1 shows a first exemplary embodiment of the display module 100 in cross-sectional view. The display module 100 comprises a carrier 1, for example made of plastic or glass. The carrier 1 comprises a front face 10 and a rear face 11 opposite the front face 10. Areas of the front face 10 and the rear face 11 are, for example, in the region between 100 cm.sup.2 and 9 m.sup.2 inclusive.

[0065] A wiring layer 3 and a pixel array comprising a plurality of pixels 2 are arranged on the front face 10 of the carrier 1. In the present case, the pixels 2 are each formed by an LED chip 20. The individual pixels 2 are electrically connected to each other via the wiring layer 3. In particular, a plurality of thin-film transistors 6 are integrated in the wiring layer 3, wherein each thin-film transistor 6 is uniquely assigned to a pixel 2. The associated pixels 2 can be switched on and off via the thin-film transistors 6. The wiring layer 3 includes, for example, a plurality of layers formed by a thin-film technique, such as a metal layer, a dielectric layer and a semiconductor layer, whereby the individual thin-film transistors 6 and the interconnection between the pixels 2 are realized.

[0066] On the front face 10 between the wiring layer 3 and the carrier 1, a receiving unit 5 comprising a first receiving element 5a in the form of a coil 50 and a second receiving element 5b in the form of another coil 50 is arranged. A transmitting unit 4 comprising a first transmitting element 4a in the form of a coil 40 and a second transmitting element 4b in the form of a further coil 40 is arranged on the rear face 11. The first transmitting element 4a is opposite the first receiving element 5a. The second transmitting element 4b is opposite the second receiving element 5b. The coils 40 may be arranged directly on the rear face 11. However, in the present exemplary embodiment, the coils 40 are arranged on an auxiliary carrier 8 and not directly on the carrier 1. For example, the coils 40 are spaced somewhat from the carrier 1. In particular, the transmitting unit 4 is not part of the display module 100 here and is preferably transportable independently of the display module 100. However, the reverse case, in which the transmitting unit 4 is part of the display module 100 and then cannot be detached from the display module 100 in a non-destructive manner, for example, is also conceivable. The coils 40, 50 are each produced in the present case, for example, by a thin-film technique.

[0067] In operation of the display module 100, a supply energy for operating the display module 100 is transmitted to the first receiving element 5a via the first transmitting element 4a. From there, the supply energy is transmitted via the wiring layer 3 to the electronics on the front face 10. Control signals or data are transmitted wirelessly to the second receiving element 5b via the second transmitting element 4b. The control signals store which pixels 2 are to be controlled in which way. The pixels 2 are then controlled in dependence on these control signals and with the aid of the supply energy.

[0068] In FIG. 2, an exemplary embodiment of a screen 1000 is shown in plan view. The screen 1000 comprises a plurality of display modules 100, for example, a plurality of the display modules 100 of FIG. 1. The display modules 100 are interconnected and arranged side by side in a direction parallel to the front face. The screen 1000 forms a video screen, for example.

[0069] In FIG. 3, a portion of an exemplary embodiment of the screen 1000 is shown. More specifically, FIG. 3 shows a display module 100 of the screen 1000 and parts of the adjacent display modules 100. In FIG. 3, only the plane in which the receiving elements 5a, 5b are arranged is shown. As can be seen, a first receiving element 5a in the form of a large coil 50 and a plurality of second receiving elements 5b each in the form of a smaller coil 50 are associated with the display module 100. For example, in the present exemplary embodiment, the pixels 2 are divided into four pixel groups, wherein a second receiving element 5b (and the corresponding second transmitting element 4b) is associated with each pixel group. The first receiving element 5a supplies all of the pixel groups and all of the remaining electronics on the front face of the display module 100 with sufficient supply power for operation.

[0070] FIG. 4 shows several exemplary embodiments of coils 40, 50 with different geometries. The coils 40, 50 are each flat coils with thin, metallic conductor paths. The thickness of the conductor paths is, for example, at most 500 nm. The coils 40, 50 of FIG. 4 differ in their geometry. The coils 40, 50 comprise, for example, 150 turns each. The widths of the conductor paths of the coils 40, 50 are, for example, around 30 μm. The spacing of the conductor paths between two adjacent windings is also 30 μm, for example. An outer diameter of the coils 40, 50 is then approximately 20 mm in each case, for example, and an inner diameter of the coils 40, 50 is approximately 2 mm in each case, for example. With such coils 40, 50, an inductance of approximately 200 μH is achieved. The square coil 40, 50 achieves particularly high inductances because it encloses the largest area. The coils 40, 50 of FIG. 4 with the specified dimensions are particularly suitable for use in a first transmitting element and first receiving element which is configured to transmit the supply energy.

[0071] Instead of one first receiving element 5a and one first transmitting element 4a per display module 100 each in the form of a single coil (see FIG. 3), it may be advantageous to use several first receiving elements 5a and correspondingly several first transmitting elements 4a each in the form of a coil 40, 50 per display module 100. For example, with a module size of 80 mm×90 mm and a pixel edge length of 1 mm, one would have a power requirement per display module 100 of 6 W at a luminance of 2000 cd/m2. The current requirement per display module 100 would then be approximately 1.5 A. With a coil thickness of about 0.3 μm, this would be a relatively large current. In this case, for example, nine first receiving elements 5a and corresponding first transmitting elements 4a would be useful. Each coil 40, 50 would then have to carry only 0.17 A. A coil edge length could be approximately 25 mm. With a width of the conductor paths of the coils of approximately 300 μm, a pitch between adjacent conductor paths of 400 μm and 31 turns per coil, the heating of the coils would be less than 20° C.

[0072] FIG. 5 again shows the section of the screen 1000 in which a display module 100 is shown in detail. However, unlike in FIG. 3, the plane in which the pixels 2 are arranged is now shown. As can be seen in the present exemplary embodiment, each pixel 2 is associated with a μLED chip 20. The areas of the pixels 2 are each larger than the areas of the μLED chips 20 by at least a factor of 5. As a result, the region between two adjacent pixels that is not illuminated during operation is relatively large. This in turn allows semiconductor chips 7a, 7b, 7c, 7d for controlling the pixels 2 to be arranged between the pixels 2 without affecting the image quality.

[0073] In the present exemplary embodiment, the display module 100 comprises an active-matrix control system. The active-matrix control system comprises a column driver comprising two semiconductor chips 7a, and a row driver comprising two other semiconductor chips 7b. In addition, the display module 100 includes a semiconductor chip 7d for data processing and a semiconductor chip 7c for power supply. The functions of the semiconductor chips 7b, 7d will be further explained in connection with FIG. 7.

[0074] An advantage of arranging the semiconductor chips 7a, 7b, 7c, 7d in the region between the pixels 2 is that this eliminates the need to arrange semiconductor chips for controlling the pixels at the edges of the display module 100, making the display module 100 appear to have no edges in operation.

[0075] FIG. 6 shows a cross-sectional view of the display module 100 shown in FIG. 5. The dashed lines indicate the boundaries between adjacent pixels 2. It can be seen that the semiconductor chips 7a, 7d are each arranged in the region between two pixels 2, in particular in the region between the LED chips 20 of two adjacent pixels 2. Furthermore, the semiconductor chips 7a, 7d are arranged here in a different plane than the LED chips 20. However, it is equally conceivable that the semiconductor chips 7a, 7d are arranged in the same plane as the LED chips 20.

[0076] In FIG. 7, a schematic switching arrangement of an exemplary embodiment of the display module 100 is shown. For example, it is the switching arrangement of the exemplary embodiment of FIGS. 3 and 5.

[0077] Image data and control signals, respectively, are present in the form of high-frequency signals. The control signals can still be modulated to increase the transmission reliability. They are forwarded to the second transmitting element 4b on the rear face of the carrier 1 via an impedance converter 21. From there, the control signals are forwarded wirelessly through the carrier 1 to the front face of the carrier to the second receiving element 5b. From the second receiving element 5b, the control signals are then forwarded to the semiconductor chip 7d, which is configured for data processing of the control signals. In particular, the semiconductor chip 7d comprises an impedance converter 70d and a demultiplexer 71d. The semiconductor chip 7d is signal-connected with the semiconductor chips 7a of the column driver and the semiconductor chips 7b of the row driver. Thus, the processed control signals are passed to the column driver and the row driver, which are then used to drive the individual pixels 2 in response to the control signals.

[0078] Supply power for the display module 100 is provided by a power supply 200. A modulator 22 at the rear face of the carrier 1 modulates the voltage and this is applied to the first transmitting element 4a at the rear face of the carrier 1. The supply energy is then transmitted wirelessly through the carrier 1 to the first receiving element 5a. From the first receiving element 5a, the supply energy is transmitted through the wiring layer 3 to the semiconductor chip 7c for supplying the voltage. This semiconductor chip 7c includes a circuit 70c for rectifying the electric voltage/current, a circuit 71c for smoothing, and a circuit 72c for stabilizing. For example, capacitors are used for smoothing.

[0079] Alternatively, the capacitors for smoothing may be integrated in the wiring layer. The pixel array is then supplied with power via the semiconductor chip 7c.

[0080] FIG. 8 shows another exemplary embodiment of the display module 100. The exemplary embodiment of FIG. 8 is similar to that of FIG. 1. Unlike FIG. 1, in the exemplary embodiment of FIG. 8, core plates 90, for example made of nickel or cobalt or iron, are arranged in a plane above the coils 50 of the first 5a and second 5b receiving elements. The core plates 90 overlap in a projection on the front face with the coils 50. The core plates 90 guide the magnetic field and thereby reduce losses.

[0081] In FIG. 9, another exemplary embodiment of the display module 100 is shown in a cross-sectional view. Unlike in the exemplary embodiment of FIG. 1, the transmitting unit 4 and the receiving unit 5 comprise electrodes 41, 51 rather than coils. The wireless energy transmission for the supply energy and the control signals is capacitive here. The electrodes 41, 51 are each preferably applied directly to the carrier 1 here.

[0082] In FIG. 10, an exemplary embodiment of the display module 100 is shown in cross-sectional view, wherein the transmitting unit 4 comprises a radiation emitting element 42, such as a semiconductor laser. The receiving unit 5 comprises a photodetector 52. The photodetector 52 may be produced using thin-film technology and may be based on amorphous silicon, for example. In operation, the radiation emitting element 42 transmits both the supply energy and the control signals to the photodetector 52. That is, the transmission of supply energy and control signals is realized in a single pair of transmitting element and receiving element.

[0083] FIG. 11 shows another exemplary embodiment of the display module 100. For example, the receiving unit 5 and the transmitting unit 4 each comprise only a single coil 40, 50 through which both the supply energy and the control signals are transmitted wirelessly. In the preceding exemplary embodiments, the transmitting unit 4 and the receiving unit 5 were each arranged overlapping, in particular completely overlapping, with the pixel array of pixels 2. In the exemplary embodiment of FIG. 11, this is not the case. Here, the projections of the transmitting unit 4 and the receiving unit 5 onto the front face 10 lie outside the corresponding projection of the pixel field.

[0084] The invention is not limited to the exemplary embodiments by the description based thereon. Rather, the invention encompasses any new feature as well as any combination of features, which particularly includes any combination of features in the patent claims, even if that feature or combination itself is not explicitly specified in the patent claims or exemplary embodiments.

[0085] This patent application claims priority to German patent application 102019123893.5, the disclosure content of which is hereby incorporated by reference.

LIST OF REFERENCE SIGNS

[0086] 1 carrier [0087] 2 pixel [0088] 3 wiring layer [0089] 4 transmitting element [0090] 4a first transmitting element [0091] 4b second transmitting element [0092] 5 receiving element [0093] 5a first receiving element [0094] 5b second receiving element [0095] 6 thin-film transistor [0096] 7a, 7b, 7c, 7d semiconductor chip [0097] 8 auxiliary carrier [0098] 10 front face [0099] 11 rear face [0100] 20 LED chip [0101] 21 impedance converter [0102] 22 modulator [0103] 40, 50 coil [0104] 41, 52 electrode [0105] 42 radiation emitting element [0106] 52 photodetector [0107] 70d impedance converter [0108] 71d demultiplexer [0109] 70c, 71c, 72c circuit [0110] 90 core plate [0111] 100 display module [0112] 200 power supply [0113] 1000 screen