WO2018172104A1

WO2018172104A1 - Display element, and device for operating same

Info

Publication number: WO2018172104A1
Application number: PCT/EP2018/055907
Authority: WO
Inventors: Istvan Denes; Alexander Fischer
Original assignee: Robert Bosch Gmbh
Priority date: 2017-03-20
Filing date: 2018-03-09
Publication date: 2018-09-27
Also published as: CN110418730A; DE102017204574A1

Abstract

The invention relates to a display element (100) comprising, between a rear substrate material (102) and a front transparent cover material (104), an electro-active component (106) for exciting the display element (100) to oscillate, and an electro-luminescent component (108) for exciting the display element (100) to light up (110).

Description

description

title

Display element and device for operating the same prior art

The invention is based on a device or a method according to the preamble of the independent claims. The subject of the present invention is also a computer program.

DE 10 2009 006 260 AI describes a remote control by haptic tracking for a central vehicle information system.

Disclosure of the invention

Against this background, the approach presented here is used

Display element, a method for operating a display element, a device that uses this method, a control element and finally a corresponding computer program according to the

Main claims presented. The measures listed in the dependent claims advantageous refinements and improvements of the independent claim device are possible.

Electroluminescence can be excited by an electric field. For this purpose, an electrically insulating phosphor can be arranged between two electrodes. The electrodes with the insulator in between form a capacitor or a capacitor. When connected to the electrodes

AC voltage is applied, the phosphor starts to light up. A vibration generating component may also be excited by an electric field. For this purpose, an electrically insulating, electroactive material can be arranged between two electrodes. The electrodes with the insulator in between form a capacitor or a capacitor. When an AC voltage is applied to the electrodes, the electroactive material deforms at a frequency of the AC voltage, and oscillation results.

In a display element, the light-generating component and the vibration-generating component can be integrated. In this case, the light-generating component and the vibration-generating component can be controlled separately.

It is presented a display element that between an rear-side support material and a front, transparent cover material, an electroactive component for exciting the display element to a

Has vibration and an electroluminescent component for exciting the display element for lighting.

A display element can be understood as part of a control element. An electroactive component may comprise an electroactive polymer and react to an applied electric field with deformation. An electroluminescent component may be a

have electroluminescent dye or an electroluminescent pigment and on an applied electric field with a

Light emission react.

The electroactive component may be disposed between the support material and the electroluminescent component. Thereby, the light of the electroluminescent component can shine through the transparent cover material.

The electroactive component and the electroluminescent component may be electrically contacted on the front side and rear side via electrodes. The electroactive component and the electroluminescent component may be contacted via a common electrode. By a

Multiple use of an electrode can save material.

Furthermore, at least one working step can be saved during manufacture. The electroactive component may comprise at least one electroactive polymer layer. The electroactive component may comprise a plurality of superimposed polymer layers. The polymer layers can be contacted individually electrically. The display element may comprise a pressure detection device, which is designed to image a pressure on the display element in an electrical signal. The pressure detection device can be integrated in the display element. The pressure sensing device may or may be further electroactive

Have component. For detecting the pressure, the same material as for generating the vibration may be used. Thereby, the structure of the display element can be simplified. The pressure detecting device can between the substrate and the

Be arranged cover material. The pressure detection device can be protected from environmental influences.

Furthermore, a device for operating a display element is presented according to the approach presented here, the device comprising the following

Characteristics comprising: a first voltage source for supplying the electroluminescent

Component; a second voltage source for supplying the electroactive component; and a logic for driving the first voltage source and the second one

Voltage source. The voltage sources can be AC voltage sources. The logic can be called a controller.

Furthermore, an operating element for a vehicle with a user interface is presented which has at least one display element according to the approach presented here and at least one device according to the approach presented here.

The operating element may comprise a plurality of display elements. Each of the display elements may be formed to display an icon displayable by a display of the control. Likewise, the

Display elements are designed as individually controllable pixels of such a display, which together can map a graphic information. For example, the display elements can be arranged side by side in a grid. Symbols and / or graphical information can also be made tactile by the vibrations.

Thus, depending on the embodiment, a display element may have an area of less than one square centimeter, less than one

Square millimeters or less than one square micron of an area of a display of the control. The smaller a single one

Display element is executed, the more finely structured can be visual or haptic pattern by the plurality of display elements of

Control element are displayed.

A method for operating a display element according to the approach presented here comprises the following steps:

Applying an alternating electric field to the electroactive component to cause the display element to vibrate; and

Applying an alternating electric field to the electroluminescent

Component to illuminate the display element. The alternating electric field can be applied to the electroluminescent component when a touch of the display element is detected.

This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the above

described embodiments, in particular when the program product or program is executed on a computer or a device.

Embodiments of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows:

Fig. 1 is a schematic representation of a display element according to an embodiment;

FIG. 2 is an illustration of an electroluminescent film; FIG.

3 is a schematic representation of a control element according to an embodiment;

Fig. 4 is a circuit diagram of an apparatus for operating a

Display element according to an embodiment;

Figures 5 to 16 representations of an operation of a control element according to an embodiment;

17 is a flowchart of a method for operating a

Display element according to an embodiment; and Fig. 18 is a schematic representation of an operating element according to an embodiment.

In the following description of favorable embodiments of the present invention are for the in the various figures

represented and similar elements acting the same or similar

Reference numeral used, wherein a repeated description of these elements is omitted.

1 shows a schematic representation of a display element 100 according to an exemplary embodiment. The display element 100 has a carrier material 102 and a transparent cover material 104. The cover material 1044 may be referred to as a transparent encapsulant. Between the

Carrier material 102 and the cover material 104 are an electroactive

Component 106 and an electroluminescent component 108 arranged. The carrier material 102 forms a rear side of the display element 100. The cover material 104 forms a front side or visible side of the display element 100. The electroluminescent component 108 is disposed between the electroactive component 106 and the cover material 104. The electroactive component 106 is configured to cause the display element 100 to vibrate when an electrical

Alternating field is applied to the electroactive component 104. The

The electroluminescent component 108 is configured to excite the display element 100 when an alternating electric field is applied to the electroluminescent component 108. The light 110 penetrates the transparent cover material 104.

In one embodiment, the display element 100 has a

Pressure detecting device 112 on. The pressure detection device 112 forms a pressure on the display element 100, for example by a finger 114, in an electrical signal.

In other words, a printed electroluminescent surface 100 having a haptic function is presented. An electroluminescent luminous surface 100 with an additional functionality, the so-called haptic functionality, is presented. For a surface 100 having a haptic function, vibrations are generated by an actuator 106. Depending on the vibration amplitude and frequency different surfaces with different textures / roughness can be simulated.

The contact force of the surface 100 can be measured by a force measurement. Once the touch force exceeds a force level, a vibration having a particular waveform can be generated. This makes it possible to give a feeling of authenticity during the operation of a virtual button. An application example is an automotive touch display with haptic function. When the display is touched, the actuator 106 generates vibrations.

FIG. 2 shows a representation of an electroluminescent film 200. The film 200 essentially corresponds to the display element in FIG. 1. In contrast to this, here the electroactive component is replaced by an insulating layer 202.

Electroluminescent coatings 200 may be used to

Light body with particularly thin layer thicknesses to make. Such

Coatings 200 may be applied to planar or curved surfaces and even to flexible plastic films. A

Electroluminescent luminescent film 200 is a light-emitting capacitor. It functions as a multilayer capacitance with pigment 204 and insulation 202 as dielectric 206.

A typical structure of an electroluminescent surface 200, the so-called "standard build" is shown in Fig. 2. On a transparent

Polymer film layer 104, such as PET, PE, Pl film 104, is deposited with a transparent electrode coating 208, such as an ITO coating or PEDOT: PSS.

This results in the so-called front electrode 208. On one edge of the front electrode 208, the front bus bar 210 is applied. For the printing of the front bus bar 210, for example, silver conductive paste can be used by means of a screen printing process. The next layer is a phosphor layer 204 For example, applied by screen printing. This layer 204 is the actual light-emitting electroluminescent layer 108. Instead of phosphorus as the light source, alternatively, other types of electroluminescent materials, such as metallic salts, may be used.

As an electrical insulating layer 202, a dielectric insulating material is applied to the phosphor layer 204. For example, barium titanates can be deposited by screen printing. As back electrodes 212, opaque electrode coatings such as carbon black or metallic coatings may also be used.

As an encapsulation, a last layer 102 may be applied, which may also be made of an opaque material. It is possible to perform the entire buildup process in a reverse order, referred to as a "reverse build." In this process, the back electrode 212 is applied as the first step to the opaque protection surface 102. The last process step is the construction by means of a transparent polymer film 104 encapsulated.

3 shows a schematic representation of a control element 300 according to an exemplary embodiment. The operating element 300 comprises a

Display element 100, which substantially corresponds to the display element in Fig. 1. Furthermore, the operating element 300 comprises a device 302 for operating the display element 100. The device 302 has a first one

Voltage source 304 for supplying the electroluminescent component 108 of the display element 100 and a second voltage source 306 for supplying the electroactive component 106 of the display element 100.

Furthermore, the device 302 comprises a logic 308 or a controller 308 for driving the first voltage source 304 and the second

Voltage source 306.

The components 106, 108 are disposed between electrodes 208, 212, 310. In this case, between the cover material 104 or the cover layer 304 and the electroluminescent component 108 is a transparent front electrode 208 arranged. Between the electroluminescent component 108 and the electroactive component 106, an intermediate electrode 310 is the

electroactive component 106 is arranged. The intermediate electrode 310 may be reflective to the light 110 of the electroluminescent component 108. Between the electroactive component 106 and the carrier material 102 or the substrate 102, a common back electrode 212 of the electroactive component 106 and the electroluminescent component 108 is arranged. The first voltage source 304 is connected to the transparent front electrode 208 and the intermediate electrode 310. The second voltage source is connected to the intermediate electrode 310 and the return electrode 212. The transparent front electrode 208 is connected to ground here. Between the back electrode 212 and the substrate 102 is here a

Insulator layer 312 and a sensor layer 314 arranged. The sensor layer 314 is part of the pressure detector 112. The pressure detector 112 provides the electrical pressure signal 316 to the logic 308. In one embodiment is between the electroluminescent

Component 108 and the intermediate electrode 310, a further insulating layer 318 arranged, since the electroluminescent component 108 may have electrically conductive components. In the approach presented here, the dielectric insulating layer as shown in FIG

Fig. 2 is replaced by an electroactive polymer layer 106. In the electroactive polymers (EAP) 106, deformation by the electric field is generated. These deformations cause the sensor surface 104 to vibrate. For this purpose, electroactive polymer types such as dielectric elastomers such as elastomers on silicone,

Polyurethane or acrylic base or piezoelectric or electrostrictive polymers such as PVDF based polymers.

The vibrations generated by the electroactive polymer layer 106 may include surfaces 104 having different roughness and / or texture imitate by means of the so-called friction modulation. This effect helps the operator to identify the active sensor area 100. As a result, a blind operation is achieved. The contact of the surface 104 is detected by a sensor unit 112. Once the touch force exceeds a predefined level and the sensor layer 314 is activated, the surface 104 may be illuminated. For the Sensierung can also a kind

Strain gauge principle (DMS) or piezoelectric or piezoresistive measuring principles are used.

In another mode of operation, vibration will only follow the

Touching the sensor surface 104 triggered. This will be a certain

Authenticity given when pressing a virtual button.

In other words, the structure of the layer system 100 is shown schematically in FIG. A central controller 308 reads the force signal 316 and, in accordance with the control algorithm, controls the voltage sources 304, 306 Ul and U2. An E-field is generated by the front and back electrodes 310, 212 of the electroactive polymer layer 106 and by the U2 AC source 306. The frequency of the excitation is in a range which is particularly suitable for producing a haptic effect. Furthermore, the geometry of the layer system 100 and the excitation frequency can be selected so that the system can be operated in a mechanical resonance. The

Vibration amplitudes in the resonance can clearly exceed the amplitudes of a quasi-static operation.

An E-field is between the front and back electrodes 208, 212 of the

Illumination generated by the Ul AC voltage source 304. The frequency of the AC voltage is in a range between 50 Hz and 4 kHz.

The same back electrode 212 may be used for both the illumination 108 and the electroactive polymer layer 106. The

Voltage amplitudes of the voltages Ul and U2 are typically in several 100 V range. In order for the user to be protected from electric shock in the event of damage to the transparent encapsulation 104, the front electrode 208 of the illumination 108 is recommended to be grounded. As the EAP functional material 106, polyvinylidene fluoride (PVDF) and its copolymers can be used. For the electrical activation of PVDF field strengths up to 200 to 300 ν / μηι necessary. In order to keep the control voltage low, the layer thickness of the EAP layers 106 can be limited, for example, to 0.5 to 2 μm. The excitation force generated by the EAP layer 106 increases in proportion to the layer thickness. In order to achieve sufficient force for the haptic function, several EAP layers 106 can be stacked on top of each other. The Gleichpolpolten electrodes are electrically connected together.

Electroactive polymer layers 106 may be used not only as an actuator but also as a force / pressure sensor 314. In this case, the change in the capacitance or the state of charge of the sensor 314 is detected. It is in a multilayer electroactive polymer layer construction

It is worth considering using a layer 314 as a sensor and the remaining layers 106 as an actuator. As a result, any additional layers for the force sizing can be omitted.

Because most of the electroluminescent materials 108, such as metallic salts, are electrically conductive, a fourth insulating layer 318 may be disposed below the phosphor 108. In this case, materials having a high dielectric constant can be used as insulator 318, so that the UV voltage predominantly falls through the phosphor layer 108 or the luminous layer 108. Since PVDF materials generally have a rather high dielectric constant, for example up to a value of 30 to 50, the same material as for the EAP layers 106 can be used for the fourth insulating layer 318. Thus, the process chain can be further simplified by using as few different materials as possible.

4 shows a circuit diagram of a device 302 for operating a

Display element 100 according to an embodiment. The circuit diagram depicts the two voltage sources 304, 306 and their power supply via a step-up converter 400 and a DC voltage intermediate circuit 402. The two voltage sources 304, 306 are here as a channel of a

dual-channel step-down converter 404.

In other words, Fig. 4 shows the circuit diagram of an embodiment of the power electronics 302. In order to generate the voltages Ul, U2, various power electronics circuits can be used. Here, as a representative of the various circuit configurations, a two-channel up-down converter 302 is shown. By actuating the switches S5, S6, the DC voltage Uv is generated. An output voltage between 0 V and Uv can be generated in channel 1 with the actuation of the switches S3, S4 and in channel 2 with the actuation of the switches Sl, S2.

FIGS. 5 to 16 show illustrations of an operation of a

Operating element 300 according to one embodiment. The operating element 300 essentially corresponds to the operating element in FIG

Operating element 300 has at least two different display elements 100 by way of example here. The display elements 100 provide two

different icons. The display elements 100 may be referred to as sensor surfaces 100 due to their pressure sensing device. A display element 100 represents a triangle for easy distinctness. The other display element here represents a circle. The control element 300 may also have a plurality of individually controllable display elements 100. The display elements may in such a case be completely or partially independently controllable individual pixels of a display matrix. As a result, almost any symbols and / or image contents can be displayed on the operating element 300. The operating element 300 here has a curved user interface 500. The user interface may be, for example, a partial area of an interior of a vehicle.

Haptic feedback 502 is particularly important in automotive engineering to ensure "blind" operability of the instruments so that visual contact with the road is not lost when operating the instruments. Not only touch displays 300, but any touch surfaces 300 may be provided with such a haptic function. In the center console panel of a car operator elements 100 may arise, resulting from the

Do not lift surface 500 of panel 300. As long as they are not operated, they also do not light up. However, vibrations 502 are generated at the operator segments. This will make it possible between

Operator segments 100 and between the passive surface segments easy to distinguish by hand. As soon as the

Operating segments 100 are actuated, there is also a visual

Feedback 110 and the element is illuminated.

In Fig. 5, both display elements 100 and sensor surfaces 100 are unlit. The display elements 100 are thus substantially invisible or inconspicuous. By the electroactive components, the display elements 100 are excited to vibrations 502, which can be felt by an operator.

In FIG. 6, a contact 600 of the user interface 500 in the area of one of the display elements 100 is detected by the pressure detection device. The operator can use a form of the symbol shown on the basis of

Feel vibrations 502.

In FIG. 7, in response to the touch, the triangle 100 is illuminated by the electroluminescent component of the display element 100 over its entire surface with light 110.

The illustration in FIGS. 8 to 10 essentially corresponds to FIG

Representation in Figures 5 to 7. In contrast, the control element 300 here per symbol two display elements 100 on. It stops

Display element 100 represents a contour 800 of the symbol while the other display element 100 represents the surface of the symbol.

In one exemplary embodiment, the contour 800 of the sensor surface 100 is illuminated in the initial situation. There are at the sensor segments 100th additionally generates oscillations 502. As soon as the operator segments 100 are actuated, the entire sensor surface 100 is additionally illuminated.

In Fig. 8, the contours of the symbols are illuminated by display elements 100 in different colors and the contour is determined by the

Vibrations 502 shown.

In Fig. 9, as in Fig. 6, the touch 600 is sensed.

In FIG. 10, as in FIG. 7, the touched symbol is illuminated in its entirety by the light 110.

In FIGS. 11 to 16, in contrast to the preceding figures, the symbols are superimposed or overlap one another. As in FIGS. 8 to 10, the contour 800 is illuminated by the pressure detection device before detection of the contact 600 and can be felt by vibrations 502. In response to the detection of the touch, the symbol is illuminated over the entire surface.

In one exemplary embodiment, the sensor surfaces 100 overlap. Only the contour 800 of the sensor surface 100, which is to be activated as a function of the context, is illuminated and brought into oscillation 502. As soon as the operator segments 100 are actuated, the entire sensor surface 100 is additionally illuminated.

In FIG. 11, the display element 100 of the contour 800 of the triangular symbol is illuminated and the triangular surface is set in oscillation 502.

In Fig. 12, the touch 600 of the triangle is recognized.

In Fig. 13, the display element 100 of the surface of the triangle is illuminated over its entire surface.

In FIG. 14, the display element 100 of the contour 800 of the circular symbol is illuminated and the circular area is set in oscillation 502. In Fig. 15, the touch 600 of the circle is recognized.

In Fig. 16, the display element 100 of the surface of the circle is illuminated over its entire surface.

17 shows a flowchart of a method for operating a display element according to an exemplary embodiment. The method includes a first step 1700 of applying and a second step 1702 of applying. In the first step 1700 of the application, an alternating electric field is applied to the electroactive component to the display element to a

To stimulate vibration. In the second step 1702 of the application, an alternating electric field is applied to the electroluminescent component to illuminate the display element. FIG. 18 shows a schematic illustration of a control element 300 according to an exemplary embodiment. The operating element 300 corresponds in this case

Essentially, the control element in Fig. 3. In addition, the

Display element 100 here a plurality of superimposed electroactive layers 106 with their associated electrodes 212, 310. The device 302 is connected to the electrodes 212, 310 such that the electroactive ones

Layers 106 are each negatively contacted on one side and positively contacted on the other side.

If an exemplary embodiment includes a "and / or" link between a first feature and a second feature, this is to be read such that the

Embodiment according to an embodiment, both the first feature and the second feature and according to another embodiment, either only the first feature or only the second feature.

Claims

claims

A display element (100) comprising between a rear substrate (102) and a front, transparent cover material (104) an electroactive component (106) for exciting the display element (100) into a vibration (502) and an electroluminescent

Component (108) for exciting the display element (100) for lighting (110).

The display element (100) of claim 1, wherein the electroactive component (106) is disposed between the substrate (102) and the electroluminescent component (108).

3. Display element (100) according to one of the preceding claims, wherein the electroactive component (106) and the

electroluminescent component (108) are electrically contacted on the front and rear via electrodes (208, 212, 310), wherein the electroactive component (106) and the electroluminescent

Component (108) via a common electrode (310) are contacted.

4. Display element (100) according to one of the preceding claims, wherein the electroactive component (106) at least one

electroactive polymer layer (106).

5. Display element (100) according to one of the preceding claims, with a pressure detection device (112) which is adapted to image a pressure on the display element (100) in an electrical signal (316).

6. display element (100) according to claim 5, wherein the pressure detecting means (112) or the further electroactive component (106).

7. display element (100) according to any one of claims 5 to 6, wherein the pressure detecting means (112) between the carrier material (102) and the cover material (104) is arranged.

8. A device (302) for operating a display element (100) according to one of claims 1 to 7, wherein the device (302) has the following features: a first voltage source (304) for supplying the

electroluminescent component (108); a second voltage source (306) for supplying the electroactive component (106); and a logic (308) for driving the first voltage source (304) and the second voltage source (306).

9. operating element (300) for a vehicle with a user interface (500) which has at least one display element (100) according to one of claims 1 to 7 and at least one device (302) according to claim 8.

10. A method of operating a display element (100) according to one of claims 1 to 7, wherein the method comprises the following steps:

Applying (1700) an alternating electrical field to the electroactive component (106) to excite the indicator (100) to vibrate (502); and Applying (1702) an alternating electric field to the

electroluminescent component (108) to illuminate the display element (100).

A method according to claim 10, wherein in said step (1702) of applying, said alternating electric field is applied to said electroluminescent component (108) when a touch (600) of said display element (100) is detected.

A computer program adapted to carry out the method according to any one of the preceding claims.

13. A machine-readable storage medium on which the computer program according to claim 12 is stored.