WO2002058040A1

WO2002058040A1 - Pixel element for a reflective display device with modifiable image, display device and system using same, method for making same

Info

Publication number: WO2002058040A1
Application number: PCT/FR2002/000193
Authority: WO
Inventors: Didier Le Gall; Yannick Le Gall
Original assignee: Didier Le Gall; Yannick Le Gall
Priority date: 2001-01-17
Filing date: 2002-01-17
Publication date: 2002-07-25
Also published as: FR2819617B1; EP1362338A1; EP1362338B1; ATE420427T1; DE60230723D1; FR2819617A1

Abstract

The invention concerns a rotor-type element (1) designed to co-operate with a stator part, having therefor at least an axis of rotation (A) parallel to the view plane, with respect to which it is adapted to pivot along specific axial positions and having at least a localised permanent polarity adapted to co-operate with at least a drive unit (7a, 7b; A, B, C) of said stator part, said element being divided into at least two angular sectors (1a-1f, 10a-10f) with different main shade and said element being a composite element consisting of a section (10) of wires. The inventive method for making said element consists in assembling the wires in contiguous fashion into a strand of wires, said strand being then cut into sections, each section corresponding to a rotary element.

Description

"Pixel-type element for a reflective display device with modifiable image, display device and system implementing it, manufacturing method" The present invention relates to a constituent element, of pixel type, for a reflective display device , that is to say visible using ambient light, and provided with a possibility of automatically controlling the displayed image. It also relates to a display device implementing said element and a manufacturing process. The targeted field is in particular that of the display on panels any format and that of the labeling of products for which a definition of the order of mm ² is sufficient.

The present invention also relates to a system implementing this display device with in particular a remote control via a control unit in connection with a communication network.

In the state of the art, there are reflective panels capable of offering several images which consist of cells with several faces of a few cm ² (often columns) and comprising a portion of printed image which is rotated jointly so as to reconstitute this image.

This type of panel has the following disadvantages in particular:

- the number of images that can be displayed per panel is limited;

- the operating cost is important because it is necessary to have an operator on site to change the cells when we want to change the series of images and it is necessary to carry out the cells with each change (manufacturing and printing).

The display systems capable of offering an infinite number of images are currently electronic systems with plasma screens and LED screens. These systems are, however, bulky, fragile and expensive, especially in terms of manufacturing and use costs because they require a constant supply of energy. They are in fact too sophisticated for the intended field of use, in particular because in this field, the poster can remain in place for a long period of time, or because the time to pass from one image to another does not doesn't need to be fast (around several seconds is enough).

The present invention aims in particular to overcome these drawbacks, namely to provide a reflective display device offering an infinity of reconstructable images, which is economically profitable in the field of display and labeling, which is robust and requiring reduced maintenance, available in all sizes and shapes.

It proposes a pixel type element for a reflective display device with modifiable image, characterized in that it is of the rotor type intended to cooperate with a stator part, having for this purpose at least one axis of rotation parallel to the plane of view, with respect to which it is adapted to pivot according to precise axial positions and having at least one permanent localized polarity and adapted to cooperate with at least one exciter of said stator part, said element being divided into at least two angular sectors of main nuance different and said element being a composite element consisting of a section of son.

It also offers a reflective display device with modifiable image, characterized in that it comprises:

- a network of juxtaposed cells, each cell being defined by:

- a rotor part consisting of a rotary element as defined above;

- a stator part comprising at least one exciter;

- Means for controlling the stator part of the cells so as to selectively rotate the rotary elements relative to their respective axis of rotation to make visible for each cell a sector chosen according to its nuance, all the sectors visible from all the cells constituting the displayed image. The polarity or polarities of the rotary element can be of the electrostatic type, the associated exciter or exciters of the stator part being electrodes.

They can also be of the magnetic type, the associated exciter or exciters being conductors supplied by a current in one direction or another.

The polarity (s) can be obtained either before mounting the rotary element or by induction after mounting.

Each cell can be compared to a "Micro Electro Mechanical System" (MEMS) from the family of actuator components. The operation is based on the addressed command of electric or magnetic fields selectively rotating the rotating elements of the cells on the desired shade, by a phenomenon of repulsion and / or attraction of polarity (s). With electrostatic polarities, the operation requires an energy supply mainly in voltage at the time of the image change. With magnetic polarities, current operation requires a low energy input.

We can use a material having for example an electrostatic or magnetic remanence capacity to maintain the orientation of the rotors.

The present invention notably offers the following advantages:

each visible part of the cell can be equivalent to a pixel of a few mm ^2, this eliminates the printing operations and an infinite number of images can be produced; - the cells can be controlled remotely: we can completely eliminate interventions on site and carry out real-time updates and animations; the device can be installed on a mobile vehicle;

- you can divide a panel into as many areas as you want and set up labeling strips with image position addressing. - The device can be thin and can be adapted to existing display media; it can have any shape.

The polarity of the rotating element can be located in one of the sectors. Another sector (preferably diametrically opposite) can have an opposite polarity in particular to balance the system and facilitate rotation.

The rotary element may have only two sectors, therefore only two shades, which is sufficient for use for example in the field of labeling. In this case, one of the sectors will be provided with a polarity and a stator with an exciter will suffice to rotate the rotary element in two positions (attraction or repulsion of the polarity).

Advantageously, each wire corresponds to a sector. According to a particularly advantageous embodiment, the rotor part is a section of wires divided into six equal sectors longitudinally, two diametrically opposite sectors are polarized in opposite directions and the other four sectors are neutral. We can thus have for the sectors the basic colors of the hexachromy. The stator part is made up of two exciters. The different possible combinations of the repulsion and polarization attraction system allow the section to pivot in the six axial positions. The colors of the sectors may also be colors chosen according to commercial criteria (for example the colors corresponding to a brand).

In a particularly advantageous embodiment according to the invention, since it is inexpensive, the sections are obtained by cutting a strand of tinted wires. In addition, it is possible advantageously to use naturally charged fibers for the yarns such as chitosan® (positively charged) or PVC (negatively charged) to obtain one or more electrostatic polarities in a simple manner. There are also magnetically polarized wires. The yarns may come from the spinning industry, the cost prices of which are advantageous.

Using this type of technique, we can also consider making threads with peripheral fibers of varying shades (mottling) to increase the definition. of the display device, in particular as a function of the angle of view.

To allow free rotation of the rotary element in its cell, it will for example be housed in a capsule filled with a non-viscous liquid of density substantially equal to that of the rotary element, or else the rotary element will have a hollow core to be able to be mounted axially in a collar, or alternatively it will be provided with guipure preventing contact with the internal wall of the capsule.

The rotors can advantageously be assembled by encapsulation in a chain in flexible tubes twisted in strings or else strung in a collar. They can also be housed in a molded or machined substrate, said substrate containing, for example, a network of conductive wires forming the electrodes of the stator parts of the cells.

Different embodiments for the stator part of the cells are possible, for example an electrode matrix, or components with direct electrodes, or even using a mixture of these two techniques.

The present invention also relates to a remote display system characterized in that it comprises: at least one transmitting site with: - data control and processing means making it possible in particular to design a poster and to transcribe said poster into a series of data picture ;

- means for transmitting said image data via a communication network; at least one receiving site with a display device according to the invention. The image data correspond to the commands of the exciters of the cells.

The present invention will be better understood and other advantages will appear in particular in the light of the description which follows, description made with reference to the drawings in which:

- Figure 1 shows a block diagram of a rotary cell comprising a pixel type element according to an embodiment of the invention with six sectors;

- Figure 2 illustrates the operation of the cell of Figure 1; - Figure 3 shows a particular embodiment of rotors based on a strand of son encapsulated in a chain;

- Figure 4 illustrates the operation of the cell of Figure 3;

- Figure 5 relates to the embodiment of Figures 3 and 4 and illustrates a means of increasing the resolution of the displayed image. FIG. 1 shows a cell comprising an element 1 of section in circular section and having a centered axis of rotation A, forming a rotor part cooperating with a stator part which will be described later. Element 1 is divided into six equal angular sectors 1 a-1f each having at least on the surface (here in all the material) a specific main shade, the six sectors corresponding for example to the basic colors of the hexachromy: cyan, yellow, magenta, black, white and flesh. The element 1 is free to rotate about its axis A. It is here for this purpose housed in a transparent and waterproof capsule 2 filled with a non-viscous liquid with a density substantially equal to that of the rotary element. In addition, to allow the rotation of the element 1, one of the sectors, 1 b in FIG. 1, is positively polarized permanently and another sector, 1 e in FIG. 1, is negatively polarized permanently , thus forming an electrostatic couple. The stator part consists of an opaque material substrate 5 shaped by molding and defining a housing with a visibility window 6 for receiving the capsule 2 while allowing its rotation with respect to the axis A. The window 6 is dimensioned so as to leave globally visible only the chosen sector of the rotary element corresponding to a chosen main shade. Two exciters, here independent electrodes 7a and 7b, are formed in the substrate 5 opposite the capsule 2 and arranged at approximately 120 ° from one another in a plane situated opposite the view plane so to be advantageously located at the rear of the cell. The electrodes are close enough, or even in contact with the capsule 2, so that they can interact with the positive charge of sector 1b and with the diametrically opposite negative charge of sector 1 e of rotary element 1.

The operation of the cell is as follows (with reference to FIG. 2): the electrodes 7a, 7b can be positive, negative or neutral polarized. From left to right in Figure 2 are represented the six possible positions:

- first position: the two electrodes are positive biased: by a charge repulsion / attraction phenomenon, the charged sector + of the rotary element is placed at 120 ° opposite to the two electrodes and the charged sector - between the two electrodes halfway; - second position: the two electrodes are polarized negative

: the charged sector + of the rotary element is placed halfway between the two electrodes and the charged sector - is placed automatically opposite;

- third and fourth positions: the electrodes 7a and 7b are selectively polarized negatively attracting opposite it the charge + of the rotary element and repelling the opposite charge -;

- fifth and sixth positions: as for the third and fourth positions but with a selective positive polarization of the electrodes. Alternative embodiments are possible, in particular one could have magnetic polarities instead of positive and negative charges and associated conductors as exciters and addressing of appropriate currents in one direction or another.

In FIG. 1, the rotary element 1 is shown in section perpendicular to its axis of rotation A. According to the invention, corresponding to the example of embodiment shown in FIG. 3, the rotary element is a composite element consisting of 'a section 10 of a few mm2 in length which was obtained by cutting a strand of six wires 10a-f assembled side by side longitudinally in hexagon to form at its periphery six angular sectors. The core of the strand is hollow. Each thread is itself made up of a set of tinted fibers then coated with a waterproofing layer 1 1 a-f. In this example, two opposite permanent charges are provided: one here corresponds to the wire 10a based on naturally positively charged fibers (for example chitosan®), the other to the wire 10d which is diametrically opposite to it and which is based naturally negatively charged fibers (e.g. PVC). FIG. 3 also shows a method of assembling sections 10 in a chain consisting of using at the start a tube made of transparent impermeable material into which a liquid 13 is introduced (which allows, as explained above, the free rotation of the section 10) and a section 10, and said material is twisted to form a chain of aligned capsules 14.

According to a possible embodiment, a display device according to the invention comprises lines of strings housed in a substrate which is complementary shaped and a network of conductive wires forming independent point electrodes, for example molded in said substrate, to form the parts. stators cooperating with the encapsulated rotors. The substrate can thus contain a network of conductive wires arranged in a grid forming the electrodes of the stator part of each cell. The device further comprises control means comprising addressing means, for controlling all of the stator parts of the cells so as to selectively rotate the rotary elements with respect to said axis to make visible for each cell a sector chosen according to its shade, all the visible sectors of all the cells constituting the displayed image. One can optionally provide means for receiving data representative of one or more images, either via a communication network or via a data reader, said reception means operating in conjunction with the means for controlling the stator parts of the cells. According to the invention, there is also provided a remote display system comprising: at least one transmitting site with:

- data control and processing means allowing in particular to design a poster and to transcribe said poster into a series of image data;

- means for transmitting said image data via a communication network; at least one receiving site with a display device according to the invention provided with appropriate reception means. This advantageously makes it possible to remotely manage the different display device (s), for example to program them in advance, on several sites simultaneously, to carry out animations etc. The communication network can be a telecommunications network, wired, wireless or a local network. FIG. 4 illustrates a variant of the operation of a rotor with six sectors. The stator part here comprises three electrodes A, B and C arranged at 120 ° from one another around the rotor and which can be positively or neutrally polarized. From left to right of the figure we see the six possible positions of the rotor: - The first three positions corresponding to the selective positive polarization of one of the electrodes leading to rotate the rotor to bring the negative charge in front of the polarized electrode; and

- The last three positions corresponding to the selective positive polarization of two electrodes leading to rotate the rotor to bring the negative charge halfway between the two polarized electrodes.

In Figure 5 is shown an alternative embodiment of the section 10 of Figure 3 to perfect the definition of the display device. It consists in providing, for example in each wire (10a) two peripheral portions (10a 'and 10a ") whose fibers have the color of the adjacent wire (respectively 10b and 10f) so as to have only one color in the field of visibility (symbolized by dotted lines) and possibly widening it. It goes without saying that other variant embodiments are also possible, for example the production of clearly submillimetric cells, by exploiting the technical potential offered by the component industry micro actuators.

Claims

claims

1. Element (1, 10) of pixel type for a reflective display device with modifiable image, characterized in that it is of rotor type intended to cooperate with a stator part, having for this purpose at least one axis of rotation (A) parallel to the view plane, with respect to which it is adapted to pivot according to precise axial positions and having at least one permanent localized polarity and adapted to cooperate with at least one exciter (7a, 7b; A, B, C) of said stator part, said element being divided into at least two angular sectors (1 a-1 f, 10a-10f) of different main shade and said element being a composite element consisting of a section (10) of wires.

2. Element according to claim 1, characterized in that the wires are assembled side by side in said section extending along the axis of rotation (A).

3. Element according to claim 1 or 2, characterized in that the section consists of six wires assembled in hexagon.

4. Element according to any one of the preceding claims, characterized in that each wire constitutes an angular sector.

5. Element according to any one of the preceding claims, characterized by a second opposite polarity.

6. Element according to any one of the preceding claims, characterized in that the polarity or polarities are each located in a sector (1 a-1 f, 10a-10f).

7. Element according to any one of the preceding claims, characterized in that the section of wires (10) comprises a naturally positively charged wire 1 b) constituting a positive electrostatic polarity.

8. Element according to any one of the preceding claims, characterized in that the section of wires (10) comprises a loaded wire naturally negatively (1 e) constituting a negative electrostatic polarity.

9. Element according to any one of the preceding claims, characterized in that each wire (10a) comprises peripheral fibers of variable colors (mottling) to increase the definition of the display device in particular as a function of the viewing angle.

10. Element according to any one of the preceding claims, characterized by an electrostatic polarity, the associated exciter of the stator part being an electrode.

1 1. Element according to any one of claims 1 to 9, characterized by a magnetic polarity, the associated exciter of the stator part being a conductor supplied by a current in one direction or another.

12. Element according to any one of the preceding claims, characterized in that it is housed in a capsule (2) provided with a window

(6) transparent.

13. Element according to claim 12, characterized in that each capsule (2; 12) contains a liquid (13) substantially non-viscous with a density substantially equal to that of the rotary element (1, 10) to allow the free rotation of this last.

14. Element according to claim 12, characterized in that it comprises a guipure which prevents contact with the capsule.

15. Element according to any one of the preceding claims, characterized in that it is encapsulated in a chain in a flexible tube (14) twisted in a chain.

16. Element according to any one of claims 1 to 1 1, characterized in that it comprises a hollow core allowing it to be mounted axially in a collar and to ensure its free rotation.

17. Reflective display device with modifiable image, characterized in that it comprises:

- a network of juxtaposed cells, each cell being defined by: - a rotor part consisting of a rotary element according to any one of claims 1 to 16;

- a stator part comprising at least one exciter;

- Means for controlling the stator part of the cells so as to selectively rotate the rotary elements with respect to their axis of rotation to make visible for each cell a sector chosen according to its nuance, all the sectors visible from all cells constituting the displayed image.

18. Device according to claim 17, characterized in that the rotary element consisting of a section divided into six longitudinal sectors, the rotor part comprises two exciters arranged at 120 ° from one another and from side to side. other from a plane perpendicular to the view plane.

19. Device according to claim 17, characterized in that the rotary element consisting of a section divided into six longitudinal sectors, the rotor part comprises three exciters arranged at 120 ° from each other.

20. Device according to one of claims 17 to 19, characterized by an opaque substrate serving as a support for said cells and each offering a window of visibility.

21. Device according to claim 20, characterized in that the substrate contains a network of conductive wires arranged in a grid forming the electrodes of the stator part of each cell, the control means of the stator part comprising addressing means.

22. Device according to any one of claims 17 to 21, characterized in that it comprises means for receiving data representative of one or more images, either via a communication network or via a data reader, said means reception operating in conjunction with the control means of the stator parts of the cells.

23. Remote display system characterized in that it comprises: at least one sending site with:

- data control and processing means allowing in particular to design a poster and to transcribe said poster into a series of image data; - means for transmitting said image data via a communication network; at least one receiving site with a display device according to claim 22.

24. A method of manufacturing a rotary element according to any one of claims 1 to 16, characterized in that the wires are assembled side by side in a strand of wires, said strand then being cut into sections, each section corresponding to a rotary element.