EP1043621A1 - Electrochromic flat panel display - Google Patents

Abstract

a) einem flächenhaften Substrat (1) aus Papier oder einem papierartigen Material,

b) einem elektrochromen Stoff, der in das Substrat (1) eingebracht und/oder auf das Substrat (1) aufgebracht ist,

c) Elektroden (3), die mit dem elektrochromen Stoff elektrisch leitend verbunden sind,

d) und Gegenelektroden (7), die mit dem elektrochromen Stoff elektrisch leitend verbunden sind,

e) wobei die Elektroden (3) und die Gegenelektroden (7) derart angeordnet und mit dem Substrat (1) verbunden sind, dass jede der Elektroden (3) mit einer der Gegenelektroden (7) und jede der Elektroden (3) mit einer anderen der Gegenelektroden (7) eine elektrochrome Zelle (10) bildet,

f) und wobei die Elektroden (3) in das Substrat (1) ragen.

The invention relates to a flat screen

a) a flat substrate (1) made of paper or a paper-like material,

b) an electrochromic substance which is introduced into the substrate (1) and / or onto the substrate (1),

c) electrodes (3) which are electrically conductively connected to the electrochromic substance,

d) and counter electrodes (7) which are electrically conductively connected to the electrochromic substance,

e) the electrodes (3) and the counter electrodes (7) being arranged and connected to the substrate (1) such that each of the electrodes (3) with one of the counter electrodes (7) and each of the electrodes (3) with a different one the counter electrodes (7) form an electrochromic cell (10),

f) and wherein the electrodes (3) protrude into the substrate (1).

Description

The invention relates to a flat screen made of paper or a paper-like Material is built up.

The increasing penetration of daily life with computerized systems led to electronic books and newspapers. The first systems are on the market that contain the data download from the Internet to a local computer and then use suitable technology, e.g. by means of Infrared transmitter, transmitted on separate, electronic screens. This electronic Books can then be read anywhere and anywhere. This will make the Elaborate technology and logistics of book and newspaper printing can in principle be replaced.

A major problem with the acceptance of the systems has so far been the requirement to display images using conventional flat screen technology. Over the centuries, the consumer has been however accustomed to paper as a medium. Paper offers unsurpassed Presentation properties: a good haptic feeling, the possibility of image display with printing inks and thus responding to the natural viewing habits of the People. The representation with printing inks also has the advantage that with increasing Illumination through artificial or sunlight creates better readability - in contrast to the previous screen technology, which offers increasingly poor readability.

More recently, flat panel displays based on electrochromy have been proposed for example in EP 0 300 917 B1. The screens have one electrode layer, one Counter electrode layer and an intermediate electrolyte layer with a electrochromic substance. A flat screen is known from EP 0 635 144 B1, in which an electrochromic substance is applied to the fibers of a fabric. The tissue and one Electrolyte layer are between an electrode layer and a counter electrode layer arranged. Finally, a flat screen with one between electrodes and Counterelectrode enclosed layer of an electrochromic substance from JP 10105917 A known.

The invention has set itself the task of creating a flat screen that is easy and inexpensive to manufacture and natural vision as much as possible accommodates.

This object is solved by the subject matter of the independent claims. Preferred Further developments are described by the dependent claims.

The invention relates to flat screens according to an electrochromic process Light modulation work. Such screens produce a high-contrast picture, allow the Viewing the picture at a flat angle and exhibit excellent Visibility even in bright surroundings, especially outdoors. The pixels of the Electrochromic screens are assigned to each other in pairs Electrodes and counter electrodes are formed in the form of electrochromic cells. There electrochromic substances are known in a wide variety, which have an optical property, for example their color or optical density, even with minor changes in the electric field of each electrochromic cell can change, the electrochromic Cells of such flat screens with inexpensive electronic control devices and addressing of the cells are operated. The electrochromic cells are each through an electrode and an associated counter electrode that is closer to the electrode than that other counter electrodes, and one between this pair of electrode and counter electrode located path or a space in between formed in or a color reaction takes place when attached to the pair of electrode and associated A minimum voltage required to trigger the color reaction is applied to the counter electrode is. The color reaction is preferably a change in color and / or optical density of the electrochromic substance.

According to the invention, the flat screen is based on paper or paper-like Material built up, which serves as a carrier substrate for at least one electrochromic substance. The electrodes protrude into the substrate and are preferably made from a pin electrically conductive material formed. The electrodes protrude from one side of the substrate the substrate into it. They preferably do not protrude through the substrate, but close to to the opposite side. They preferably protrude at least 70% or, more preferably at least 80% of the thickness of the substrate. For example, the substrate a thickness of 50 µm, the pins protrude from the back of the substrate preferably at least 40 µm, for example 45 µm, into the substrate. The Electrodes are formed on front pin portions of the pins. In preferred Versions, the electrodes are formed at the front pin ends or become whole simply formed by the front pin ends. The pens also serve as Fastening means for the electrodes and preferably also for the associated ones Conductor tracks.

The counter electrodes can basically on the opposite side of the substrate be connected to the substrate, for example by laminating a film as a carrier. However, the counter electrodes are particularly preferably arranged on the side of the substrate, where the electrodes protrude into the substrate. In this preferred embodiment becomes a front side of the screen according to the invention facing the viewer received, which corresponds perfectly to the impression of printed paper. The counter electrodes can also be formed by pins, but shorter than the pins used for the Electrodes are preferred. The pins for the counter electrodes would above Numerical example preferably protrudes between 5 and 10 µm far into the substrate. Through the However, using paper or a paper-like material would also work Laminating the counter electrodes by means of a layer of transparent conductor tracks on the front because of the use of paper or a paper-like material and the arrangement of the electrodes in the substrate, in particular by means of the pins, a simple and therefore get inexpensive flat screen that is still stronger than that well-known electrochromic working flat screens the impression of printed paper mediates, for example a glossy paper.

For the purposes of the invention, a pencil is understood to mean any structure that is in the substrate can be pressed in, in particular any slim cylindrical body, knobs or pointed expiring thorn.

There will be paper or a corresponding porous or fibrous material in any Size used as substrate material. Under a suitable for the purposes of the invention, paper-like material is understood to mean a material that prints or like a paper can be soaked and made of fibers, such as plastic fibers, under Use of an adhesive and / or binder formed, preferably made like paper becomes.

For the purposes of the invention, an electrochromic substance is any dye based on a electric current changes at least one of its optical properties, for example its color or its optical density. All pH-sensitive, redox-sensitive or otherwise by the electrical current directly or indirectly changeable dyes. Dyes that are colorless are preferred react to color, e.g. Phenolphthalein. The substances to be selected should not bleeding. A preferred reversible coloring is physicochemically pH-sensitive or redox-sensitive dyes. Preferably the or the Dyes printed on the substrate or impregnated into the substrate. The substrate is preferably impregnated with a non-evaporating or low-evaporation electrolyte or soaked. Other auxiliaries can be impregnated, such as preservatives, Stabilizers, auxiliary reactants for the color reaction etc. The one necessary for the color representation Redox or pH gradient is generated by microelectrodes and counter electrodes. The Microelectrodes and counterelectrodes are of different types in high density arranged distributed over the surface of the substrate. They are controlled in a defined manner.

Around the single electrode or counter electrode, i.e. in the electrochromic cell by suitable control of the applied voltage or the flowing current desired pH value is set. The develops depending on the pH dye used corresponding color. A corresponding current with reversed polarity erases the coloring again.

The electrodes and counter electrodes can be used as pH measuring electrodes or redox measuring electrodes be used. Instead, or in addition, separate pH measurement pairs can be used or redox measuring pairs from electrodes and counter electrodes can be integrated. A regular or periodic pH measurement or redox value measurement enables this Correction of any pH shifts or redox shifts and thus maintaining the desired basic pH or basic redox value based on a target-actual comparison.

The same applies here and below for the use of redox-sensitive dyes. In the electrochromic cells is adjusted accordingly by adjusting the voltage or the Current desired set or maintain a redox value.

The electrodes and counter electrodes are preferably made so thin that a optical impairment does not arise. Instead of metallic material, it can also be electrical conductive plastic used as electrode material and / or counter electrode material become.

A possible embodiment can be that thin, wire-shaped on or in the substrate Conductor tracks are applied once in a horizontal and once in a vertical arrangement become. The horizontal conductor tracks are sequential with a suitable clock frequency e.g. controlled from top to bottom and the vertical conductor tracks e.g. from left to right right, at a defined point in time only flows at the intersection of the controlled conductor tracks the applied current through the substrate and developed exactly a color point at this point. In this way, the entire screen area can be scanned and an image and text representation can be built on the software side. The deletion takes place at Use of a pH-sensitive dye correspondingly with reverse pH shift on an underlying.

1. pH- oder redox-sensitive Farbstoffe, z.B. die drei Grundfarben und Schwarz, werden in je einer Lage schichtweise übereinander aufgebracht. Die dem Betrachter zugewandten Lagen werden transparent ausgeführt. Jede Lage wird durch nur in dieser Lage wirkende Elektroden spezifisch angesteuert. Eventuell sind isolierende Zwischenlagen vorgesehen.

2. Das Substrat kann stattdessen auch einlagig mit einem Mikro-Pixelmuster oder Mikrolinienmuster der Grundfarben bedruckt oder imprägniert sein. Die Ansteuerung der jeweiligen Farbpunkte erfolgt dann durch Elektroden und Gegenelektroden, die nebeneinander spezifisch nur im Pixel oder der Linie einer der Farben angeordnet sind.

3. Geeignete pH- oder redox-sensitive Farbstoffe mit Farbumschlag bei unterschiedlichen pH-Werten oder Redoxwerten werden in Mischung aufgebracht. Die gewünschte Farbe entsteht dann durch die Einstellung unterschiedlicher, definierter pH-Stufen oder Redoxwert-Stufen pro Elektroden-/Gegenelektrodenpaar bzw. elektrochromer Zelle.

A screen according to the invention can be constructed in a wide variety of ways using the system described. The following principles can be applied:

1. pH or redox-sensitive dyes, such as the three primary colors and black, are applied in layers on top of each other. The layers facing the viewer are made transparent. Each layer is specifically controlled by electrodes that act only in this layer. Insulating intermediate layers may be provided.

2. Instead, the substrate can also be printed or impregnated in one layer with a micro-pixel pattern or micro-line pattern of the primary colors. The respective color dots are then controlled by electrodes and counterelectrodes, which are arranged next to one another specifically only in the pixel or the line of one of the colors.

3. Suitable pH- or redox-sensitive dyes with a color change at different pH values or redox values are applied in a mixture. The desired color is then created by setting different, defined pH levels or redox levels for each pair of electrodes / counter electrodes or electrochromic cell.

By applying a surface layer or intermediate layer, the stability of the Screen will be increased. Protection and / or insulation layers can be applied, especially on the back of the substrate. A haptic or visual impression can do so to be changed. In particular, a protective layer for protection against UV radiation or are applied to the substrate to prevent evaporation of an electrolyte. The protective layer can be sprayed on, for example. If it is formed by a laminated film, so can this film, if it is not electrically conductive, at the same time as a carrier film for the Conductor tracks of the counter electrodes and preferably also as a carrier film for the Serve counter electrodes.

The screens can be used in any design and use. For example, multiple screens can be merged into books or magazines become. Two screens according to the invention can also be used as intermediate insulation sheet on both sides be attached to each other.

The flat screens can be designed as billboards or tarpaulins of any size and e.g. used in street advertising.

Furthermore, T-shirts or other items of clothing can be wholly or partly with one integrated screen according to the invention are manufactured. Such clothes can be designed according to the wishes of customers when selling. With reversible The color of such a piece of clothing can also be changed again.

It can be done by integrating a screen into plastic parts or by applying on any other building materials motor vehicles or facades designed and are used in particular as changeable advertisements, for example advertising spaces.

A combination with solar collectors made of fiber material is also possible. Here, the solar collector fibers can power the units autonomously take.

Instead of or in combination with the conveyance of information or visual impressions a flat screen according to the invention can also perform other functions, e.g. in the Heat regulation. A darkly controlled surface can absorb heat, while control to light colors or white rejects heat. This can for example for a piece of clothing or a building that is equipped with an inventive Screen area is equipped to be advantageous.

The production of the screen according to the invention is simple. The substrate will obtained by consolidation and shaping from a fiber suspension. Is the substrate Paper, so any method known from paper manufacture for the production of the Substrate can be used. When using plastic fibers instead of cellulose fibers, such as this also corresponds to a preferred embodiment of the invention, the production takes place of the substrate preferably also comparable to paper production.

The at least one electrochromic substance can be added to the fiber suspension, so that with the formation of the substrate, the electrochromic substance is already homogeneous in the substrate distributed. The substrate can also be formed with the at least one after its formation electrochromic substance are coated, especially by means of printing technology known methods, for example flexographic printing. In the case of a color screen several different electrochromic substances, for example one substance for each of the three Basic colors and a material for black, in a defined layer thickness on top of each other Surface of the substrate applied, which is also conventional in each layer application Printing technology can be done. Instead of placing several layers of fabric on top of each other can also use several different electrochromic substances on a color screen each individually in the form of regularly arranged micropixels or microlines impregnated or applied, in particular printed, in a single layer.

The pins are arranged in the substrate so that the electrodes are electrically conductive with the electrochromic substance. Are several electrochromic substances in layers applied one above the other, for example, pens of different lengths can be used be, namely a certain pin length per layer. The pins are then designed that the respective electrodes are only electrically conductive with one of the layers are connected and only form electrochromic cells. Are the different electrochromic fabrics in the form of pixels or fine lines in a single layer distributed, so several individually controllable electrodes are next to each other arranged so that the color pixels can be controlled individually. In the case of pixel-shaped or line-shaped application of several different electrochromic A single counter electrode for the multiple electrodes of the fabric can be fabricated per pixel Pixel or preferably one counter electrode per color and pixel, i.e. Per Electrode.

The electrodes can be before, during or after the formation of the substrate in the material for the substrate or be arranged in the finished substrate. So the pens, which ones form the electrodes, are pressed into the finished substrate from one side, for example with a die. The application or introduction of the electrochromic substance or the plurality of electrochromic substances before or after the placement of the electrodes respectively.

However, the electrodes can also already be inserted into the suspension or with the Pour the suspension. If the substrate is formed by paper, this can be done on the Sieving table of a paper machine. Also an impression of the not yet complete solidified and formed web is still possible inside the paper machine. Analogous the above applies also when using only paper-like material, for example a material made of plastic fibers.

The electrodes are preferably formed in a mesh-like grid. In a first Lanes of the grid running in the direction connect those along the respective lane arranged electrodes electrically conductive with each other. The crossways to it serve the stabilization and spacing of the conductor tracks and thus for the formation of areal grid. However, they consist of a non-conductive material or are electrically insulated from the conductor tracks, so that none of these connecting tracks Short circuits can be generated. Basically, the electrodes can also can be introduced into the substrate in strips or even individually. Preferably the Before the conductor tracks are surrounded by electrical insulation up to the electrodes. The Electrodes can be fixed in a grid in a single step in the substrate are placed and are then already at the same time with each other via the conductor tracks connected and connectable to a power source and control device.

In the same way, the counter electrodes can already be arranged in the substrate can also be formed by means of a grid. Such a grid also points in a first Direction of adjacent conductor tracks and transverse to it Connecting tracks that serve as spacers. Preferably the Counter electrodes behind the electrodes, i.e. in the rearward extension of the electrodes, in pressed the substrate, being between the electrodes and counter electrodes by insulation a short circuit is prevented. The conductor tracks of the electrodes and the conductor tracks of the Counter electrodes intersect after the electrodes and counter electrodes have been arranged. In this case, the electrochromic cells thus formed are addressed by means of a matrix control.

The above-mentioned tracks can be flexible or rigid in the form of strips or in the form of webs or Wires are formed.

Figur 1

ein Substrat, in dem Elektroden und Gegenelektroden an einer Seite des Substrats hintereinander im Substrat angeordnet sind,

Figur 2

einen Querschnitt durch das Substrat der Figur 1 entlang einer Leiterbahn mit Elektroden und

Figur 3

einen dazu rechtwinklig verlaufenden Querschnitt entlang einer Leiterbahn mit Gegenelektroden.

The invention is described below using an exemplary embodiment. Features explained using the exemplary embodiment further develop the invention in the disclosed combination of features and also individually in each case. Show it:

Figure 1

a substrate in which electrodes and counter electrodes are arranged one behind the other in the substrate on one side of the substrate,

Figure 2

a cross section through the substrate of Figure 1 along a conductor track with electrodes and

Figure 3

a cross-section running at right angles to it along a conductor track with counter electrodes.

Figure 1 shows a paper substrate 1 with a single electrochromic substance and with a Electrolyte is impregnated. In the back of the substrate 1 are pins of an electrical conductive material pressed in the arrangement of a plaid pattern. The viewer Front ends of the pins facing the screen form electrodes 3. The electrodes 3 are arranged in lines and perpendicular columns in the substrate 1. The distances between the lines and the distances between the columns are the same. The one in a column Arranged electrodes 3 become electrically conductive by one conductor track 5 per column connected with each other. For the counter electrodes 7 (FIGS. 2 and 3) for the electrodes 3 are arranged in a line counter electrodes 7 by a conductor 8 electrically connected together. The conductor tracks 5 and 8 intersect. she are with a current source and a control device for matrix addressing connected or connectable and by columns and rows by means of matrix addressing controllable.

FIG. 2 shows a section through the substrate 1 parallel to one of the conductor tracks 5 Electrodes 3 are formed by free, front pin ends of the pins 2. Pins 2 and the conductor tracks 5 are also pressed completely into the substrate 1, i.e. in the substrate 1 embedded. The conductor tracks 5 and adjoining, rear pin sections 4, in Embodiment of the pin feet protruding from the conductor tracks 5, of a electrical insulation 6 and are so against the surrounding substrate 1 and electrochromic substance and an electrolyte introduced therein, if such an additional one is introduced, isolated. At the same time, the insulation 6 short-circuits the Electrodes and counter electrodes of the individual electrochromic cells prevented. Pins 2 can, as in the exemplary embodiment, straight-cylindrical or, for example, with mandrels pointed front ends are formed.

The counter electrodes 7 are behind the pins 2 and conductor tracks 5 in alignment with the pins 2 also pressed into the back of the substrate 1. The counter electrode 7 will directly formed by the conductor tracks 8. The conductor tracks 8 are only for this purpose provided with sections of electrical insulation 9, as best shown in FIG. 3 is recognizable. Along the conductor tracks 8 are regularly insulated alternately Conductor sections and non-insulated interconnect sections formed, the not insulated conductor track sections which form counter electrodes 7. For attachment, in particular for anchoring, the conductor tracks 8 in the substrate 1 can be located at suitable locations Conductor tracks 8 anchoring pins may be formed, which are also opposite the substrate 1 are electrically isolated. The counter electrodes 7 can themselves serve as fasteners, if, like the electrodes, they are formed by pins, which are then preferably essential are shorter than the pins for the electrodes.

In the exemplary embodiment, the pins 2 protrude perpendicularly from the conductor tracks 5. You can instead, it should also be designed in such a way, for example projecting obliquely from its conductor track that the electrodes are a little bit laterally offset from the conductor track, so that each the electrodes of the counterelectrode assigned to it directly across the substrate surface opposite. Such an arrangement is by inserting the electrodes in a fiber suspension easily produced for the substrate. Also casting around with one Suspension is easily possible. An impression of something already shaped Substrate is also possible, in particular before final solidification of the substrate.

Each of the electrodes 3 forms a counter electrode 7 arranged behind it electrochromic cell 10. When applying a characteristic of the electrochromic substance Voltage flows between a driven electrode 3 and its associated one Counter electrode 7 is an electrical current in the respective electrochromic cell 10 desired change in the optical property, for example a color change, causes. The electrodes 3 and 7 adjacent to an electrochromic cell 10 are of the respective electrochromic cell 10 so far away that between two adjacent electrochromic cells 10, no current flow takes place, the disturbing Could trigger color reactions.

Reference list

1

Substrate

2nd

pen

3rd

Electrode, front pin section

4th

rear pin section

5

Conductor track

6

isolation

7

Counter electrode

8th

Conductor track

9

isolation

10th

electrochromic cell

Claims (14)

Flat screen with a) a flat substrate (1) made of paper or a paper-like material, b) an electrochromic substance which is introduced into the substrate (1) and / or onto the substrate (1), c) electrodes (3) which are electrically conductively connected to the electrochromic substance, d) and counter electrodes (7) which are electrically conductively connected to the electrochromic substance, e) the electrodes (3) and the counter electrodes (7) being arranged and connected to the substrate (1) such that each of the electrodes (3) with one of the counter electrodes (7) and each of the electrodes (3) with a different one the counter electrodes (7) form an electrochromic cell (10), f) and wherein the electrodes (3) protrude into the substrate (1). Flat screen according to claim 1, characterized in that the electrodes by Pins (2) are formed. Flat screen according to claim 2, characterized in that each of the pins (2) having a front pin section including a pin end and an adjacent rear pin section (4) protrudes into the substrate (1), the electrodes (3) are formed on the front pin sections and the rear pin sections (4) have electrical insulation (6) on their surfaces exhibit. Flat screen according to the preceding claim, characterized in that the rear pin section (4) of each of the pins (2) with an electrical conductor track (5) is electrically connected. Flat screen according to one of the two preceding claims, characterized characterized in that the counter electrodes (7) from the front pin portions of the Pins (2) are arranged behind the rear pin sections (4). Flat screen according to the preceding claim, characterized in that the counter electrodes (7) are formed directly by at least one conductor track (8) become. Flat screen according to the preceding claim, characterized in that the conductor track (8) with a broken electrical insulation (9) on its surface has electrically non-insulated surface sections and which are not electrically isolated surface sections which form counter electrodes (7). Flat screen according to one of claims 1 to 5, characterized in that the Counter electrodes are formed by pins that protrude into the substrate. A method of manufacturing a flat panel display, the method comprising the following steps: a) formation of a flat substrate (1) made of paper or a paper-like material with an electrochromic substance which is distributed in or on the substrate (1), b) arranging electrodes (3) in the substrate (1) such that the electrodes (3) protrude into the substrate (1) and are connected in an electrically conductive manner to the electrochromic substance, c) and arranging counter electrodes (7) in the substrate (1) such that the counter electrodes (7) are electrically conductively connected to the electrochromic substance and each of the electrodes (3) is connected to one of the counter electrodes (7) by an electrochromic cell ( 10) forms. Method according to the preceding claim, characterized in that Pins (2) are formed from an electrically conductive material, each of the pins (2) is surrounded in a rear pin section with insulation (6) and in a front pin section which contains a free end of the pin (2), is not electrically isolated and the pins (2) are arranged in the substrate (1) such that they are on one side of the substrate (1) protrude into the substrate (1) and the front pin sections Form electrodes (3). Method according to one of the preceding claims, characterized in that the counter electrodes (7) are also arranged in the substrate (1). Method according to one of the preceding claims, characterized in that the electrodes (3) are pressed into the substrate (1) after the formation of the substrate (1) become. Method according to one of the preceding claims, characterized in that the counter electrodes (7) after the formation of the substrate (1) in the substrate (1) be pressed. Method according to one of claims 9 to 11, characterized in that the Electrodes (3) and preferably also the counter electrodes (7) with a liquid Fibrous ― encapsulated suspension or placed in a liquid fibrous suspension and the suspension is solidified and shaped into the substrate (1).

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