WO1999046749A1

WO1999046749A1 - Dot element of magnetic or electric conducting material, method to activate said dot element, and a display comprising said dot elements

Info

Publication number: WO1999046749A1
Application number: PCT/SE1999/000363
Authority: WO
Inventors: Mats BJÖRKMAN
Original assignee: Mobitec AB
Current assignee: Mobitec AB
Priority date: 1998-03-09
Filing date: 1999-03-09
Publication date: 1999-09-16
Anticipated expiration: 2000-09-09
Also published as: CA2323436A1; AU2865399A; SE9800746D0; EP1066614A1; JP2002507005A

Abstract

The present invention relates to a dot element with magnetically or electrically conducting material forming part of an information display and for setting in one of at least two display positions. The invention is characterized in that the dot element is pivotably arranged around a pivot protruding essentially perpendicular from the surface of said display portion, and that the display portion (1) has an upper side with at least two different light generating and/or light reflecting areas (v; s).

Description

DOT ELEMENT OF MAGNETIC OR ELECTRIC CONDUCTING MATERIAL, METHOD TO ACΗVATE SAID DOT ELEMENT, AND A DISPLAY COMPRISING SAID DOT ELEMENTS

The present invention relates to a dot element with a magnetic or electric conducting material, a method to activate said dot element, and an information display using said dot element.

The expression "dot element" used herein is more specifically related to a flat disc shaped body adjustably arrangable in at least two positions and in said two positions showing two different colors and /or different reflecting properties dependent upon the position set.

The prior art discloses dot elements being pivotable along diametral passing through axes by the influence of a magnetic field and having a light and a dark side, of which several are included in an information display. Many of these prior art dot elements are comparatively complex in design, will ask for rather big forces to be pivoted and will as a rule be too slow to be used in showing moving pictures. Examples of prior art dot elements are disclosed in US-A- 3 991 496 and in US-A-4 156 872. One method to influence dot elements in an information display is disclosed in US-A-4 733231 using permanent magnets and coils.

The main purpose of the present invention is to obtain a dot element with and/or of a magnetic or electric conducting material and forming part of an information display and to be set in one of at least two display positions.

Another object of the present invention is to obtain a technique decreasing the numbers of dot elements needed to obtain text and/or pictures, at the same time as the costs for producing informations displays with several cooperating dot elements will be reduced.

Yet another object is obtain dot elements capable of showing more than two colors.

Still another object is to obtain a technique to influence the dot elements by an electric or magnetic interaction to be easily and rapidly adjustable during a low consumption of energy.

Another object of the present invention is to obtain dot elements for display modules, wherein the dot elements can be adjusted or pivoted so fast between a "light" and a "dark" display position that moving pictures will be obtained.

Still yet another object of the invention is to obtain a dot element allowing the presentation of words and pictures with a greater contrast and readability compared to what is possible with known dot elements and information displays accordning to prior art.

Yet a last object of the invention is to obtain a technique allowing a simpler manufacturing of an information display.

The above mentioned objects are obtained by the present invention having the characterizing clauses mentioned in the claims.

By a dot element being pivotable around a pivot protruding essentially perpendicular from the surface of the display element, and that the display element has an upper surface with two separate light generating and /or light reflecting fields, wherein the dot elements can shift positions rapidly and in an energy saving way by a simple rotation.

The torque to be overcome will be low at the same time as the bearing support of the dot elements won't be subjected to uneven stresses.

Preferably the dot element will have, in addition to said pivot, an annular or oval plate forming the display surface or portion. The advantage of said annular display portion is that more than two colors can be used in the one and same element, while the display portion, preferably being formed as a square, will have four smaller display portions, two lighter and two darker being pivoted in steps of 90° to change from a light to a dark display position, or vice versa.

Perpendicularly from the display portion a protruding pivot passing through a plate having cables for momentary producing of a magnetic field is arranged, whereby the display portion will be close to the plate and to said generated magnetic field, and thus, by being made of a material being influenced by a magnetic field, it will be rotated around said pivot.

There are several ways of activating each dot element, i.e. turn it just a fraction of a whole revolution. It is possible to use the magnetic field from an electromagnet or from a permanent magnet to attract a soft magnetic material in the display portion, or it is possible to use a field from an electromagnet to magnetize a magnetizable material in or in connection to the display portion. It is always possible to use the field from an electromagnet to simul- ataneously attract and repel a permanent magnetic material in or in connection to the display portion, or to use an effect of current vortices being generated when an alternating magnetic field is passing a surface conducting a current flow. An display portion of electrically conducting material will use said last mentioned princip. Then the display portion can form part of a very thin Al plate and the base of an etched conductable pattern, or of a conducting matris wherein the current direction and puls time are individually programmable for each conductor. Hereby the need for diods can be eliminated.

The torque needed to turn a dot element in such a way that its displaying portion will shift position does not have to be big. An annular magnet can be arranged around the rotation pivot of the display portion in such a way that, by influence from a generated magnetic field, generate the torque needed to shift the display portion. An annular magnet around the rotation pivot of the dot plate will also give, compared to the arrangement of magnetic or electrically conducting material at the pherifery of the plate, advantages by having less inertia forces to handle.

By having two outsides screened in such a way that the straight incoming light will essentially just be reflected in one or more certain pivoting positions of the dot it will be possible to efficiently take advantage of both incoming day-light (from above) and an illumination (from below).

By having several dot elements arranged overlapping, inclined and adjacent each other on a display or screen and by feeding current to the cables in connection to the plate during an electronic control programmed texts and/ or pictures can be shown on the display (screen). The base plate can, except being a conducting matris only, be a circuit board with etched circuits too, which circuits can be used to lead a time controlled current generating a magnetic flux.

Preferably the axis of the dot element is inserted and supported by a bearing i the base plate. Possibly the axis can also be axially supported with a bearing towards a support behind the base plate.

To achive a rapid and an exact turning of the plate, e.g. 90° or 180°, i.e. from a stationary starting position to another set position a breaking magnetic field can be induced in the base plate following the accelerating torque. This will make it possible to obtain a fast change of the set turning position of the dot.

The invention will now be described in connection to shown embodiments in the enclosed drawings; wherein

Fig. la and lb are diagrammatic perspective views of two different dot elements according to the invention; Fig. 2a, 2b and 2c are diagrammatic perspective views of three different ways of rotating the dot elements arranged in a base plate;

Fig. 3a, 3b, 3c, 3d and 3e are diagrammatic perspective views of three different ways of supporting with bearings and a side view resp a view from above of the design of the dot elements;

Fig. 4 is a side view of a reflecting dot surface being made to be able to reflect sun light and light from a lamp;

Fig. 5a and fig. 5b shows examples of sets of round and squared dot elements forming part of an information display; and wherein

Fig. 6 shows examples of text written with the dot elements according to the invention compared with text written with conventional prior art dot elements.

Fig. la and lb are diagrammatic perspective views of two different dot elements according to the invention. Each dot element 2a, 2a' having a pivotable or rotatable part with a lighter (white) and a darker (black) field, v and s, respectively and which form the displaying part. An axis of rotation 3, 3' is arranged perpendicular from the displaying part. The displaying part can, as mentioned in the preamble, be made of a soft magnetic material, of a magnetizable material, or of a permanent magnetic material.

Annular dot elements will enable the display to have more than two colors. Also a grey-scale from black to white can be used, which puts a higher demand onto the control of the dot element which has to be able to be stopped at one or at more exact positions except at their end positions.

Squared dot elements will enable a halving of the number of dot elements needed without change of dissolution. The technique using squared dot elements will imply that two forth of the dot element always is displayed and that said element is turned 90° or 180° to obtain the color combination wanted.

Each dot element is rotably supported on a plate - see also fig. 3 - and overlapp eachother - see fig. 4. By being turned mutually the differently colored portions at each overlapping display element will take an displaying position showing either a light or a dark surface (e.g. yellow or black). Preferably the turning of each dot element is achieved by a changing or "wandering" magnetic field activating the display element or its pivot.

In fig. 2a is shown how magnetic fields generated by coils 5 act onto a flap formed periphery of a dot element 2 carried on a base plate 4, i.e. as a reluctance motor with an unipolar wave action. By using the pivot as magnetic "reconductor" the air gap can be held small and constant. The C-C distance between the flaps is one module bigger than the distance between the coils 5 to obtain a possible 3-phase drive. The coils 5 are winded and have diods. The number of winding turns is dependend on the desired turning velocity and the current available. A variant of what is shown in fig. 2a is when a magnetic material is arranged in the periphery of the display element. Thus here the magnetic material itself is used as a reconductor for the magnetic flux. The air gap will be somewhat bigger, but the weight and the torque necessary will be lower. If necessary a mechanic stop can be arranged here too to hold the display element in one of its two end positions.

In fig. 2b a permanent magnet 6 is arranged around the turning pivot 3" supporting the display element 2a". Preferably in this design the field from an electromagnet is used to simultanously attract and repel a permanent magnetic material.

Fig. 2c shows a variant to generate a magnetic field for driving/rotating the display element having etched matris patterns 8 onto a base plate 4 and having surface mounted diods 7.

Fig. 3a is a diagrammatic first perspectiv view of a first way to support the dot element with bearing, wherein the display element 2 has a central micro bearing 9. This micro bearing 9 is suitably snapped into the bearing /supporting position in the lower support having an appropriately designed recess allowing said insertion by a snap-in action.

Fig. 3b is a diagrammatic perspective view of a two point bearing with a mechanical anvil. By the support 4 below, recieving the magnetic flux generating means, a pivot 3 with a stopping arrangement 11 is extended. The end of this pivot 3 is supported in the base plate 10 having a recess for the bearing.

In fig. 3c a variant of the embodiment according to fig. 3b is shown, but now having a magnetic anvil 13. This way to support will provide a minimum of friction. The display element 2 with pivot 3 is recieved in position by a permanent magnet which also can form an active part in the turning of the display element by an influence from magnetic fields generated in coils being unwind 6 around four (or more) flaps 12 being punched out of the base plate 4.

In fig. 3d a side view of a preferred embodiment of a dot element 2 is shown and which has been supported in a holder 17 also recieving coil cores 18 (preferably made of Fe) and on which cores coils 5 have been arranged. A permanent magnet 19 (e.g. of FeNdb) is arranged on the axis of the dot element 2 in close connection to the upper sides of the coils 5 and are influenced by the magnetic fields generated by said coils 5, (See also fig. 3e). Here the connection 21 of current to one of the coils is arranged by a lower building module 22. Preferably this module carries five dot elements 2 with holders 17. By this figure the inclination of the dot elements is shown in such a way that two adjacent dot elements can overlap each other.

Fig, 3e is a view from above of the arrangement with permanent magnets 19 and their relation to the upper sides of the coils 5. By a suitable activating of the coils 5 magnetic fields can be generated in such a way that the permanent magnets 19 will be attracted and repelled alternating by these fields. An accurate control of the magnetic fields generated (regarding time and strength) by said coils 5 will be used to rapidly pivot one of the dot elements for a fraction of a full revolution.

Fig. 4 shows how a reflecting, milled dot surface can be arranged to be able to reflect both light 14 from the sun and light 15 from a lamp 16.

Fig. 5a and 5b are examples of a set of annular and squared display elements, respectively.

Fig. 6 shows the difference of a text written with an annular 10 mm display element according to the invention compared with 10 mm display element according to prior art. Thus the plainness and the readability will be much better with display elements according to the invention as it appears in the enclosed claims.

Claims

7CLAIMS

1. A dot element with magnetically or electrically conducting material forming part of an information display and for setting in at least two display positions, characterized in that the dot element is pivotably arranged around a pivot protruding essentially perpendicular from the surface of a display portion, and that the display portion (1) has an upper side with at least two different light generating and /or light reflecting areas (v; s).

2. A dot element according to claim 1, characterized in that the display portion (1) is an essentially circular or oval plate.

3. A dot element according to claim 1 or 2, characterized in that the pivot extends through a plate having conduits for generating magnetic fields.

4. A dot element according to claim 2 or 3, characterized in that magnetic material is arranged in connection to the periphery of the display portion.

5. A dot element according to claim 2 or 3, characterized in that a permanent magnet is arranged in connection to the axis of rotation.

6. A dot element according to any of the preceeding claims, characterized in that the outer surface is screened in such a way that incoming light will be reflected essentially in just one or more certain pivoting positions of the dot.

7. A method to activate a dot element according to claim 1, characterized in that current coils are activated, wherein the generated emk will pivot the dot element relative to a plate recieving said dot element.

8. A method according to claim 7, characterized in that current during time control is passing the current coils arranged in a pattern onto and /or into the plate so that an electric and /or magnetic alternating action will be generated between the induced EMK of the coils and the dot element. o

9. A method according to claim 8, characterized in that the feeding of current to the conduits in connection to the plate is done with the aid of a microprocessor.

10. Information display, characterized in that several dot elements according to some of the claims 1 to 6 and mutually overlapping each other are rotably arranged onto a plate.