EP1075686B1 - Flexible touch-sensitive matrix cathode ray tube - Google Patents

Abstract

The invention concerns a touch-sensitive matrix cathode ray tube (10) for inputting and displaying data comprising a plurality of carbon nanotubes (14, 16, 18, 20) defining a plurality of pixels and a plurality of inputting elements. The invention is characterised in that it consists of a dot matrix of (26) each dot comprising a pixel and an inputting element, each pixel made up of at least one end of three mutually parallel nanotubes and each transmitting in one of the three primary colours (14, 16, 18), the input element being constituted of the end of at least a fourth nanotube (20).

Description

The present invention relates to touch matrix screens and, more particularly, such screens produced by implementing a plurality of nanotubes.

Traditionally, in IT matters, entering data is carried out by means of a keyboard or mouse type device, while the visualization is obtained by means of a screen of the tube type cathodic or liquid crystal or plasma type.

CRT screens are heavy and bulky, and have a high radiation harmful to the user. Crystal screens liquids or plasma are smaller, but they are very fragile and do not have a very high gloss. In addition, the screens field effect dishes remain very expensive due to manufacturing necessarily noticeably artisanal.

In general, the fact that the seizure body is usually separated from the display means leads, with the computer means, to a disjunction between the grasping hand and the gaze that controls, unlike a traced on paper where the hand and the eye operate simultaneously in the same place.

To overcome this drawback, we have developed touch screens by pointing a finger or a stylus on a screen to control a computer. However, these systems remain heavy and do not allow a very good resolution, for example when entering a drawing or text using a stylus. In addition, some flat screens do not tolerate pressure local, even minimal, of a finger or a stylus is applied to them.

The object of the present invention is to obviate the drawbacks aforementioned by determining a flexible matrix screen and light touch allowing a precise input.

The invention uses a plurality of nanotubes.

As we know, nanotubes are tubes formed of carbonaceous sheets arranged in hollow concentric cylinders and uncovered in 1991 by Sumio Lijima. For the record, a nanotube is a compound polymer only carbon and it is a periodic unidirectional crystal.

Many publications have been made on the manufacture of nanotubes. One can, for example, consult the review LA RECHERCHE n ° 307, of March 1998, the journal SCIENCE, Volume 282, of November 6, 1998, or the document WO-A-97/19208, One can also consult on the subject of nanotube manufacturing and applications the following sites on the Internet all having the prefix http: // www., namely archipress.org, cerca.umontreal.ca/science, research.ibm.com/topics, amsci.org/amsci/articles, and many others.

The present invention is situated in this context and makes it possible to remedy the limitations of traditional screens and, as a result, contribute, in particular but not exclusively, for better domestic use and IT professional.

The primary object of the present invention is to determine a screen tactile matrix not having the aforementioned drawbacks.

Another object of the invention is to determine such a matrix screen touchscreen of very small thickness and which is flexible and not very fragile.

These objects are achieved, in accordance with the invention, with a screen tactile matrix for data entry and display in color including a plurality of carbon nanotubes determining a plurality of elements image and a plurality of input elements.

According to the invention, this touch matrix screen consists of a dot matrix each comprising a picture element and a captured, each picture element being constituted by an end of at least three nanotubes parallel to each other and each emitting in one of three fundamental colors, the input element being constituted by the end of minus a fourth nanotube.

Advantageously, each point is constituted by a plurality of nanotube ends of which at least four are made active.

Preferably, the nanotubes of each point are separated and held in position by means of a filling material which is, for example, consisting of a plurality of non-active nanotubes.

Preferably, each image element comprises a multiple of three active nanotubes respectively connected in parallel.

Preferably also, the end of each active nanotube of each picture element is covered with a phosphor of one of the colors fundamental.

La Figure 1 est une représentation schématique partielle et vue de dessus d'un écran matriciel tactile conforme à l'invention ;

La Figure 2 est une vue en coupe de l'écran de la Figure 1 selon un premier mode de réalisation de l'invention ; et

La Figure 3 est une vue en coupe de l'écran de la Figure 1 selon un deuxième mode de réalisation de l'invention.

The invention will be better understood, and other objects, advantages and characteristics thereof will appear more clearly on reading the following description of preferred embodiments given without limitation and to which a plate of drawings is attached. on which:

Figure 1 is a partial schematic representation and top view of a matrix touch screen according to the invention;

Figure 2 is a sectional view of the screen of Figure 1 according to a first embodiment of the invention; and

Figure 3 is a sectional view of the screen of Figure 1 according to a second embodiment of the invention.

We will now refer to the attached drawings, which are only illustrative, in particular because the scales are not respected. Indeed, the diameter of a nanotube is of the order of twenty nanometers (20 x 10 ^-9 m), while the elementary pitch of a screen point is of the order of 0.2 millimeter (200 x 10 ^-6 m).

In Figure 1, we have partially and schematically shown seen from above, i.e. seen from the part observed by the user, a corner of a screen 10 according to the invention. This screen 10 has a large plurality of points 12 substantially, but not necessarily, square in shape with a side of about 200 µm.

Each point 12 includes an image element and an capture.

The picture element consists of at least a set of three separate nanotubes parallel to each other 14, 16, 18, each emitting in one fundamental colors used in television screens or computer, namely red, green and blue.

In order to increase the brightness of the resulting screen, several nanotubes in the same point 12 and emitting in the same color can be electrically connected in parallel. In that case, each image element of each point 12 comprises a multiple of three active nanotubes respectively connected in parallel.

The gripping element consists of a fourth nanotube 20 whose apparent end then functions as the drain of an effect transistor field.

Conveniently and advantageously, the ends not visible nanotubes are either bundled together in a collector 22 and connected to a socket 24 forming a connector for a central unit forming a control member and a detection member (not shown in the Figures).

The active nanotubes 14, 16, 18, 20 of each point 12 are separated and held in position by filling material 26. This filling material 26 is advantageously constituted by a plurality non-active nanotubes and / or other nanoparticles, for example carbon.

According to a first embodiment illustrated in Figure 2 representing in section the matrix screen of Figure 1, on which only two nanotubes 14 and 16 have been shown, these nanotubes 14, 16 are bent so as to form a bundle of nanotubes whose other ends are connected to the central unit.

A luminescent film 30 is placed on the points 12 opposite the user, in particular to protect the latter, while a web 32 of protection is applied on the opposite side.

According to another embodiment illustrated in Figure 3 which represents, also in schematic section, the screen of Figure 1, the nanotubes 14, 16; 14 ', 16', etc ... are arranged parallel to each other and do not are not bent. An electrical conductor 34, 34 ', etc. is connected to each of the nanotubes 14, 16 so as to apply the required electrical voltage to the invisible end of the nanotubes. These drivers are brought back to connector 24 via collector 22.

A protective fabric 32 is glued to the sheet of conductors 34, 34 'on the invisible underside of the screen 10.

The visible end of each of the active nanotubes 14, 16, etc. is covered with a phosphor 36, 36 'emitting in one of the three colors fundamental as described above,

A transparent plastic film 30 covers the screen. This film is isolated electrically of the opposite ends of the nanotubes. It's a film conductor connected to a reference potential, for example earth 38, so to constitute an anode for the plurality of cathodes formed by the nanotubes of the picture elements.

Preferably, the nanotubes 14, 16, etc. are generated directly on and in a woven carbon fiber tablecloth found under the reference 40 in Figure 3, since this tablecloth then acts as maintenance of nanotubes.

As the person skilled in the art will have understood, one thus obtains a matrix touch screen 10 having the aforementioned advantages. Such a screen can easily be made in all the desired dimensions, for example for a traffic or advertising sign, or for a watch face, or a display screen attached to a plastic card of the smart card type, with possibly a photovoltaic cell allowing an electrical supply autonomous.

This screen is not fragile, it is even flexible and can therefore be rolled up on itself during transport. In addition, the low power required to operate it allows it to be used in a rather hostile environment.

A particular advantage of such a matrix touch screen is that it is possible to use as a table to lay, for example, a plan or a paper document, and very easily obtain a computer input of the plan by simply following the lines drawn with a thin stylus or even on point.

Although we have represented and described what we consider currently be the preferred embodiments of the present invention there it is obvious that a person skilled in the art can make various changes to it and modifications without departing from the scope of the present invention as defined by the attached claims.

Obviously, the use of such a matrix touch screen does not prevent the entry of data by conventional means such as than a keyboard, mouse, or controller.

Claims (12)

1. Touch-sensitive matrix screen (10) for capture and display in colours of data comprising a plurality of carbon nanotubes (14, 16, 18, 20) determining a plurality of picture elements and a plurality of capture elements, characterised in that it is constituted by a matrix of dots (26) each comprising a picture element and a capture element, each picture element being constituted by one end of at least three parallel nanotubes each transmitting in one of the three basic colours (14, 16, 18), the capture element being constituted by the end of at least one fourth nanotube (20).
2. Matrix screen according to claim 1, characterised in that each dot (12) is constituted by a plurality of ends of nanotubes of which at least four (14, 16, 18, 20) are activated.
3. Matrix screen according to claim 1 or 2, characterised in that the nanotubes of each dot (12) are separated and held in position by means of a filling material (26).
4. Matrix screen according to claim 2, characterised in that the said filling material (26) is constituted by a plurality of non-active nanotubes.
5. Matrix screen according to one of claims 1 to 4, characterised in that each picture element comprises a multiple of three active nanotubes (14, 16, 18) respectively connected in parallel.
6. Matrix screen according to any one of the preceding claims, characterised in that the end of each active nanotube of each picture element is covered by a luminophore (36, 36') of one of the basic colours.
7. Matrix screen according to any one of the preceding claims, characterised in that the said nanotubes (14, 16, 18, 20) are bent so as to form a bundle of nanotubes the other ends of which are connected to a central unit comprising a control element for the nanotubes constituting the picture elements and a detecting element for the nanotubes constituting the capture elements.
8. Matrix screen according to any one of claims 1 to 6, characterised in that the said nanotubes (14, 16, 18, 20) are rectilinear and parallel to one another, the ends remote from the said dots being connected to a central unit comprising a control element for the nanotubes constituting the picture elements and a detecting element for the nanotubes constituting the capture elements.
9. Matrix screen according to any one of the preceding claims, characterised in that the wall constituted by the said dots (12) is covered by a transparent plastic film (30).
10. Matrix screen according to claim 9, characterised in that the said plastic film (30) is a conductive film forming a plurality of anodes opposite the corresponding plurality of ends forming cathodes of the nanotubes constituting the picture elements (14, 16, 18) and insulated in relation to these.
11. Matrix screen according to claim 9 or 10, characterised in that the said plastic film (30) is luminescent.
12. Matrix screen according to any one of the preceding claims, characterised in that the nanotubes (14, 16, 18, 20) are produced on a woven sheet of carbon fibres (40).

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