DE102007041876A1 - Touch sensitive display device e.g. thin film transistor display, has touch sensitive device provided in viewing direction on display arrangement and on rear side of display arrangement, and actuated by touching display arrangement - Google Patents

Abstract

The device (10) has a display arrangement (11) for displaying content, and a touch sensitive device comprising a sensor element (17). The touch sensitive device is provided in a viewing direction on the display arrangement and on a rear side of the display arrangement. The sensor element is actuated by touching the display arrangement, where the sensor element is designed as a piezoelectric motion sensor element and/or an acoustic sensor element. The motion sensor element is formed as an acceleration sensor element and/or accelerometer element.

Description

The The present invention relates to a touch-sensitive Display device according to the preamble of claim 1.

touch-sensitive Display devices, also called "Touch-Screen" are known, are already known in a variety of ways. Here, a touch-sensitive layer on the View side of the display (the display) applied. at Touching a finger becomes a touch sensor triggered, leaving the coordinate of the touch can be determined.

Previously known Solutions describe, for example, a touch-screen technology, in the case of a touch-sensitive device, the actual Screen device, such as a display technology such as backlit TFT displays (Thin Film Transistor), self-luminous OLED displays (Organic Light Emitting Diode) or the like, upstream is.

Previously known Examples include the so-called "resistive technology". Here are two layers of a conductive material in front of the screen device for use. The two layers are over spacers separated from each other. When touched, the senior Layers pressed together in the appropriate place, whereby an electrical connection is made.

at The "capacitive technology" becomes a transparent transistor matrix in front of the display device (the display).

The Technology of "Projected Capacitance" is characterized by this made that thin traces in front of the screen device are provided. It will be the change in the electrostatic Field detected. The disadvantage here are in addition to the aforementioned disadvantages also a visual impairment of the "wires" and an electrostatic effect of surrounding components.

at the "Frustrated Total Internal Reflectance" becomes infrared light fed into the protective layer of the display and below the Screens detected. The disadvantage here is in addition to the aforementioned disadvantages also that fixation of the display on a hard substrate, For example, glass, is required.

In The recent past has also been various solutions known in the field of non-self-luminous displays. This includes for example, the so-called electronic paper. electronic Paper, in short E-paper, is usually electrophoretic Technology based paper-like digital display technology. The e-paper consists of one on a light, often white, Substrate attached electrically conductive foil, the small cells contains. Color pigment particles in these cells react on electrical voltage. By attaching a voltage, the Representation on the e-paper color-by-cell by cell which creates a digital overall picture of all cells. Compared to conventional displays, e-paper unites the advantages of electronic displays and paper, since no backlight an almost paper-like high contrast ratio achievable is. Furthermore, the display can be viewed independent of viewing angle and also on a very thin, flexible substrate be applied.

A Property of not self-light emitting displays is in Unlike traditional self-luminous, mostly on solid surface applied display technologies such as TFT or OLED that such displays without additional backlight are dependent on the maximum reflection of the incident light, for maximum readability. This applies to e-paper displays as well as on many others, applied on a reflective background conventional display technology too. For journalistic applications is the best possible light reflection, and therefore the highest Contrast ratio, but of top priority, for the best possible readability of the presented "print" content to reach.

adversely however, in the prior art technologies, such is one attached in front of the actual display - for example capacitive or resistive - contact layer, absorbed a not inconsiderable part of the amount of reflected light. This is acceptable as long as the screen setup over has a sufficiently strong backlight. Since displays that emit no light themselves, not by a illumination behind the display (backlight) would be lit, one on the visible side of the display attached touch-sensitive device (touch technology) the contrast advantages, for example of e-paper displays, cancel. The disadvantages usually include a significant loss of light or the required fixation on a solid substrate.

It Therefore, solutions have already become known in which the touch-sensitive device on the back, instead of as before on the visible side of the opaque Displays, attached, reducing the disadvantage of light absorption can be bypassed. The position of the touch is here recorded on the back of the display.

such Technologies require, for example, a media unusable Use of a magnetic pen or a high contact pressure on the display technology.

In "Magnetic Technologies "are triggered by a magnetic pin inductive currents through at the back of the screen device or the display device attached wires detected. The disadvantage here is that no finger operation possible is, but that a magnetic pen must be used.

A "resistive technology" is for example in the WO 2007/012899 A1 described, from which the present invention proceeds. This provides two layers of conductive material which are separated from spacers and which make electrical contact upon contact in the manner described above. These two layers represent the touch-sensitive device, wherein the layers form a corresponding sensor element. The solution disclosed in this document has a touch-sensitive display device, which initially has a screen device for displaying content. In the direction of the screen device is on the back (this is the side of the screen device that is opposite the actual viewing side), the touch-sensitive device provided in the known solution behind an electronic device, a so-called "backplane electronics".

adversely in this known solution is that when mounting the resistive technology on the back of the screen device or the display device a high pressure on screen device and Backplaneelektronik must be exercised so that the Resistive functions can be triggered. This can damage the display technology.

outgoing Of the cited prior art, the present invention therefore the object of a touch-sensitive display device of the aforementioned type, such that the described Disadvantages can be avoided. In particular, should a be provided touch-sensitive display device, at the lowest possible pressure on the screen device nevertheless good operability of the touch-sensitive Device is guaranteed.

These The object is achieved by the touch-sensitive display device with the features according to the independent claim 1. Further features and details of the invention will become apparent from the Subclaims, the description and the drawings.

According to the invention a touch-sensitive display device is provided, with a screen for displaying content and with a touch-sensitive device, comprising at least one sensor element, wherein the touch-sensitive Device in the direction of the screen device on the Rear of the screen device is provided, and wherein the at least one sensor element by touching the screen device is operated or is operable. The touch-sensitive display device according to the invention thereby characterized in that at least one sensor element as a motion sensor element and / or is designed as an acoustic sensor element.

The Touch-sensitive display device according to the invention Provides a touch-screen technology, especially for non-light-emitting screen devices (displays), such as For example, electronic paper, is suitable, and the on a special embodiment of the sensor elements for motion detection and / or acoustic detection based.

there the display device initially has a screen device for displaying content. Naturally the invention is not limited to certain types of screen devices limited. Suitable screen devices can, for example be flexible or not flexible. Advantageously the screen device as a non-self-luminous screen device be educated. In such a case, the screen device particularly preferably designed as so-called electronic paper be. Electronic paper is one in itself already known display technology, for example, from a on a light, often white, surface may consist of electrically conductive film, wherein the film is small Contains cells.

Color pigment particles in these cells react to electrical voltage. By attaching a tension can be the representation on the electronic paper Cell by cell can be changed, thereby a digital overall picture of all cells is created.

Furthermore, the touch-sensitive display device has a touch-sensitive device which has at least one sensor element. In this case, the touch-sensitive device can be designed in such a way that the sensor element (s) are arranged or formed on a substrate, advantageously on a thin, flexible substrate. Of course, it can also be provided that the / the sensor element (s) for ge represent the touch-sensitive device, and that the / the sensor element (s) is arranged or formed on a further device / are. It would be conceivable, for example, for the sensor element (s) to be designed or arranged on the rear side of the screen device or for the sensor element (s) to be arranged or formed on the rear side of an electronic device, for example a so-called backplane electronics is / are, or that the / the sensor element (s) is arranged or formed on the back of the display device / are. The invention is not limited in this regard to specific embodiments. It is only important that the touch-sensitive device in the direction of the screen device behind this, and thus on the side facing away from the visible side of the screen device side of the screen device, is provided.

The Touch-sensitive device is in the direction of the screen device on the back (here These are the visible side of the screen setup opposite side) is provided. "Intended" can thus mean that the touch-sensitive Device arranged directly on the back of the screen device or is formed. But "foreseen" can also mean that the touch-sensitive device over an intermediate device is arranged on the screen device is. The intermediate device may be, for example, a Electronic device, such as a so-called backplane electronics act over which at least individual components of the touch-sensitive display device driven and operate.

Advantageous can / can the screen device and / or the touch-sensitive Device and / or optionally an intermediate layered be educated. Particularly preferred may be these layers be flexible, either the facilities themselves already flexible, or on a flexible Substrate are arranged.

The touch-sensitive device functions such that the on / in this located at least one sensor element Touch the screen device (especially on its Visible side) is actuated or actuated can be.

Advantageous it is provided that the touch-sensitive display device as a whole is flexible. In such a case can the display device is bent so that it the user Feeling, a flexible medium, such as a piece of paper or the like to hold in your hand.

Advantageous is the display device or the screen device, also flexible in such a way that they are impressed on their point of view can be and that the pressure passed through the screen device can be. Once the pressure, for example, over a finger is exerted, stops, the returns Contour of the screen device, or the contour of the Visual surface, in their - advantageous flat - output contour back.

According to the invention now provided that at least one sensor element in a special way is trained.

For this is at least one sensor element as a motion sensor element and / or designed as an acoustic sensor element.

in principle it is sufficient if the touch-sensitive device has a single sensor element, which then in the aforementioned Way is formed. Advantageously, however, it is provided that the touch-sensitive device two or more sensor elements, particularly preferably a larger number, that is four or more sensor elements having. In this case can then be provided be that all sensor elements either as motion sensor elements, or are formed as acoustic sensor elements. Naturally Combinations are also conceivable in which the touch-sensitive Device comprises at least one motion sensor element and at least having an acoustic sensor element. The invention is not limited to one limited number or design of the sensor elements. Some advantageous but not exclusive examples will be explained in more detail later in the description.

One fundamental problem with touch-sensitive Display devices in which the touch-sensitive Device provided in the viewing direction in front of the screen device was, was that such mounted in front of the actual display Touch layer a part of the reflected light amount absorbed. Since displays that emit no light themselves, not Illuminated by a back-light illumination, would be one attached to the visible side of the display Touch technology the contrast advantages, for example of e-paper displays, pick up. The inventive Touch-sensitive display solves this Problem by the touch technology on the back instead of on the visible side of the opaque display is attached, thereby bypassing the disadvantage of light absorption can. The position of the touch is here on the back of the display.

Of the Core of the solution according to the invention consists in the use of one or more specially designed Sensor elements on the back of the screen device, wherein the sensor elements on the position of the touch the front of the screen device (the visible side) can. The sensor elements recognize the touch or the finger tip and allow the calculation the coordinate. This will cause navigation through the screen device (E-paper, for example) content within the represented by the sensor elements resolution allows. In addition, this can be Fully operate and require technology with your finger no compromise on the reflection properties of the screen device.

In order to prevent that on the display device and optionally on the intermediate layer with the electronic device, a high pressure must be exerted to actuate the at least one sensor element, which in the WO 2007/012899 A1 is described and can lead to damage of the display device, but at least to an inaccurate operation of the same, the present invention now has specially designed sensor elements in the form of motion sensors and / or acoustic sensors.

As has already been stated above, one of the sensor elements can be advantageously designed as a motion sensor element. In a motion sensor element it is generally a sensor element which is used for measurement of motion quantities, such as way, speed or acceleration, or to measure force effects, such as Force, moment, strain, is trained. In this regard, the invention is not limited to certain embodiments of limited the motion sensors.

Advantageous can at least one sensor element designed as a motion sensor element as Acceleration sensor element may be formed. An acceleration sensor is generally a sensor that measures the acceleration. Thus, for example determine whether an increase in speed or - decrease takes place. An acceleration sensor can be used in many different ways be educated. An accelerometer becomes common also known as accelerometer.

Advantageous can at least one sensor element designed as a motion sensor element as Be formed vibration sensor element. When using more as two sensor elements can of course also Combinations of acceleration sensor elements and vibration sensor elements be used.

One Vibration sensor element is basically a sensor, which absorbs vibrations and these into electrical signals transforms. Of course, the invention is not on limited to certain types of vibration sensor elements. Preferably, at least one designed as a vibration sensor element Sensor element may be formed as a vibration sensor element.

One such vibration sensor absorbs the vibrations, that is the vibrations, advantageously by free-swinging structures, and converts them into electrical signals. For example, could be provided that the vibration sensor is a housing in which a cantilevered structure is arranged, and the vibrations occurring with a contact element on the housing comes into contact. If this is the case, an electric Pulse triggered. The electrical impulses are in one Electronics evaluated and in application-specific switching commands implemented.

Preferably can at least one designed as a motion sensor element sensor element be designed as a piezoelectric motion sensor element. such Sensor elements are based on the piezoelectric effect. When piezoelectric Effect arises when pressure is applied to an electrically polarized Crystal an electrical voltage. The piezoelectric effect is based on the phenomenon that in the deformation of certain materials on the surface electric charges occur. He describes thus generally the interaction of mechanical pressure and electrical Stress in solids.

In In an advantageous embodiment, sensor elements in the form of vibration sensors, for example based on piezoelectric accelerometers, used.

As has already been stated above, one of the sensor elements can be advantageously formed as an acoustic sensor element. An acoustic sensor is characterized by the fact that it detects sound waves, and converts these into suitable signals, such as electrical signals. In this regard, the invention is not limited to certain embodiments limited for the acoustic sensors.

Advantageous can at least one acoustic sensor element as electro-acoustic Transducer may be formed.

Touching a display surface, such as the viewing surface of the display device, generates sound waves that are above the display rate Rial, about the material of the screen device to which or the electroacoustic transducers are forwarded. Advantageously, it can be provided that two or more such electro-acoustic transducers are provided, which are provided at a distance from each other. For example, the acoustic sensor elements could be provided at the edges of the display device.

One electroacoustic transducer generates the acoustic waves corresponding electrical signals. The position of the touch on the Display surface, for example, by comparing the signals determined by several electroacoustic transducers. noise can be differentiated using suitable algorithms and filtered out.

As has already been explained above, is the present Invention not on a certain number of sensor elements, or but limited to a particular arrangement of the sensor elements. following Some will be beneficial in this respect, but not exclusive examples explained.

For example two or more sensor elements may be provided, wherein the sensor elements on the edge of the screen device or the display device are provided. The sensor elements can then on the edge of the back of the screen device or the display device, advantageously in the corners. Important in the arrangement of the sensor elements is present all this that the position of a touch on the Front of the screen setup can determine and allow the calculation of the corresponding coordinate.

In another embodiment, two or more sensor elements be provided, wherein the sensor elements in the form of a matrix Sensor elements are provided. The invention is not on limited to a certain number of matrix columns and matrix rows.

The Invention will now be based on embodiments below With reference to the accompanying drawings explained in more detail. Show it

1 a schematic representation of an already known in the prior art, conventional touch-sensitive display device with a backlit screen device;

2 a schematic representation of another, already known in the prior art, conventional touch-sensitive display device, but with a screen device without backlighting;

3 a schematic representation of a first embodiment of a touch-sensitive display device according to the invention; and

4 a schematic representation of a second embodiment of a touch-sensitive display device according to the invention.

In 1 is a conventional touch-sensitive display device known in the art 10 shown at the first screen device 11 is provided. This may, for example, be a conventional active display, for example a TFT display or the like. The screen device is a device 13 assigned to generate a backlight. In the direction of view 16 on the screen device 11 that is on the visible side 18 , is a touch-sensitive device 12 arranged, for example, a touch-sensitive, resistive or capacitive layer. When touched with a finger, a corresponding, provided there touch sensor element is triggered, so that the coordinate of the touch can be determined. The control of the individual components of the display device 10 via an electronic device 14 , which is also formed layered in the example shown and is designed as a so-called backplane electronics.

A problem with such known display devices 10 is that one before the actual screen setup 11 (the actual display) attached touch-sensitive device 12 For example, a capacitive or resistive contact layer absorbs a portion of the amount of light exiting. This is fine as long as the screen setup 11 over a sufficiently strong backlight 13 features.

Now in the past, touch-sensitive display devices 10 become known that emit no light itself and not through a behind the screen device 11 lying backlight 13 be illuminated. Such a known from the prior art solution is in 2 shown.

In 2 is a screen device formed in the form of a layer of electronic paper 11 shown on a thin, very flexible substrate in the form of a reflective layer 15 is applied. As such screen devices 11 that do not emit light themselves, not through one behind the screen device 11 lying lighting would be lit, one in line 16 on the visible side 18 the screen device 11 attached touch-sensitive device 12 the contrast advantages of electronic paper aufhe ben. At the in 2 illustrated, known from the prior art solution is therefore provided that the touch-sensitive device 12 in the direction of view 16 on the screen device 11 only behind the back 19 is provided. In the example shown, the touch-sensitive device 12 even below the reflective layer 15 and the layered electronic device 14 intended. By the touch technology 12 on the back side 19 instead of on the visible side 18 the opaque display 11 is appropriate, the disadvantage of light absorption can be avoided. The control of the individual components of the display device 10 again takes place via an electronic device 14 , which is also formed layered in the example shown and is designed as a so-called backplane electronics.

The essence of the invention will now be apparent from the particular embodiment of the touch-sensitive device 12 like this in the 3 and 4 is shown. The present invention is based on a touch-sensitive display device 10 according to 2 So, with regard to their basic structure, first to the comments on 2 is referenced. However, the touch-sensitive device according to the invention has at least one sensor element, which is designed in a special way.

The core of the solution according to the invention consists in the use of one or more sensor elements 17 that the touch-sensitive device 12 represent, and in the in the 3 and 4 illustrated examples in the direction of the back of the electronic device 14 are arranged. At the sensor elements 17 it is advantageous to acoustic sensors and / or motion sensors, such as in the form of vibration sensors. The sensor elements 17 recognize the touch or the finger tip and allow the calculation of the corresponding coordinate on the screen device 11 ,

In 3 An exemplary embodiment is shown in which the sensor elements 17 in the form of a matrix of sensors on the back of the display 10 are arranged or formed. In such a case, for example, be provided that the sensor elements 17 in the form of motion sensors in the form of vibration sensors, for example based on piezoelectric accelerometers are formed.

In 4 are the sensor elements 17 at the edge of the back of the display device 10 arranged or trained. In such a case, the sensor elements 17 be formed for example in the form of electro-acoustic transducers. Will the screen setup 11 Touched on the visible side with his finger, so sound waves are generated, which on the material of the individual layers of the display device 10 to the electroacoustic transducers 17 to get redirected. There, the sound waves are converted into electrical signals. By means of suitable algorithms, it can be determined by the different points in time when a wave is one of the electro-acoustic transducers 17 achieved, where the finger touch position on the screen device 11 located. It is not necessary, the duration of each wave to the different transducers 17 to eat. When the waves are the first of the electroacoustic transducer 17 Rather, it is sufficient to determine relative to this time when the waves are the other transducers 17 to reach. On the basis of these different points in time, the starting point of the sound waves, which corresponds to the point of contact through the finger, can then be calculated by means of suitable evaluation algorithms.

10

touch-sensitive display

11

Setup screen

12

touch-sensitive Facility

13

Facility for generating a backlight

14

electronic device

15

reflective layer

16

line of sight

17

sensor element

18

Main page the screen device

19

back the screen device

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - WO 2007/012899 A1 [0014, 0033]

Claims (8)

Touch-sensitive display device ( 10 ), with a screen device ( 11 ) for displaying content and with a touch-sensitive device ( 12 ), comprising at least one sensor element, wherein the touch-sensitive device ( 12 ) in the viewing direction ( 16 ) on the screen device ( 11 ) on the back side ( 19 ) of the screen device ( 11 ), and wherein the at least one sensor element by touching the screen device ( 11 ) is actuated or actuated, characterized in that at least one sensor element ( 17 ) is designed as a motion sensor element and / or as an acoustic sensor element. Touch-sensitive display device according to claim 1, characterized in that at least one sensor element designed as a motion sensor element ( 17 ) is designed as an acceleration sensor element and / or as a vibration sensor element. Touch-sensitive display device according to claim 1 or 2, characterized in that at least one sensor element designed as a motion sensor element ( 17 ) is formed as a piezoelectric motion sensor element. Touch-sensitive display device according to claim 2 or 3, characterized in that at least one sensor element is formed as a vibration sensor element and that the vibration sensor element is designed as a vibration sensor element. Touch-sensitive display device according to one of claims 1 to 4, characterized in that at least an acoustic sensor element is designed as an electroacoustic transducer is. Touch-sensitive display device according to one of claims 1 to 5, characterized in that two or more sensor elements ( 17 ) are provided, and that the sensor elements ( 17 ) at the edge of the display device ( 10 ) are provided. Touch-sensitive display device according to one of claims 1 to 5, characterized in that two or more sensor elements ( 17 ) are provided, and that the sensor elements ( 17 ) in the form of a matrix of sensor elements ( 17 ) are provided. Touch-sensitive display device according to one of claims 1 to 7, characterized in that the screen device ( 11 ) is designed as a non-self-luminous screen device.