GB2161307A - Display element - Google Patents

Abstract

A display element comprises a flap 1 mounted in a forked portion 5 of a frame 4 to be movable between a display position and a retracted position; a permanent magnet 10 moving along with said flap; and an electromagnet 11 stationarily mounted adjacent said permanent magnet, whereby the movement of the flap is effected by reversing the polarity of the magnetic field of the electromagnet each time so that the adjacent poles of the permanent magnet and the electromagnet repel each other. The flap 1 and the permanent magnet 10 are mounted on a pivotable member mounted on the forked position of the the frame, the pivotable member being of such dimensions that the flap on the two positions and during the pivoting movement thereof is outside the outlines of said forked portion 5 viewed in the direction of the pivot axis 9 of the pivotable member. The display element may form part of a matrix display or a segment type display. <IMAGE>

Description

SPECIFICATION Display element This invention relates to a display element.

It has long been known to use electric lamps as display elements in different kinds of information boards, whereby e.g. letters and numerals are made visible by switching on certain lamps and by switching off others. Disadvantages are poor visibility in the daytime and high consumption of electricity.

Recently, electric lamps have more and more been replaced with display elements provided with pivot flaps. A pivot flap is provided with a brightcoloured display surface and a so called background surface, usually black, whereby the display surface corresponds to a lamp switched on and the background surface to a lamp switched off. Besides a better visibility, a further advantage of the present pivot flap elements is the low consumption of electricity, which has been achieved by utilizing a combination of an electromagnet and a permanent magnet, whereby a desired pivoting movement of the flap is effected by means of a short current pulse.

The invention is particularly relevant to a display element comprising a flap mounted in a forked portion of a frame to be movable between a display position and a background position; a permanent magnet movable with said flap; and an electromagnet stationarily mounted adjacent said permanent magnet, the movement of said flap being effected by reversing the polarity of the magnetic field of the electomagnet so that adjacent poles of the permanent magnet and the electromagnet repel each other.

However, a disadvantage of known elements of this type is that each flap size has required a separately dimensioned frame, which has unreasonably increased the production costs of information boards. For the same reason, the known frame structures of display elements, which are primarily intended for displaying letters, are not suitable for a so-called segment display of numerals, but different devices have been used for this purpose. In the application of the invention to this type of element, therefore, the flap and the permanent magnet are mounted on a pivotable member mounted in the forked portion of the frame, the pivotable member being of such dimensions that the flap in the two positions and during the pivoting movement thereof is outside of the outlines of the forked portion viewed in the direction of the pivot axis of the pivotable member.

At least in the preferred embodiments the display element allows the use of a fastening frame and a pivot mechanism of a standard size practically regardless of the size of the pivot flap.

The pivotable member preferably resembles a broad U, whereby an elongate or rodlike permanent magnet is positioned inside one side portion of the U and the electromagnet is so positioned that either end of the permanent magnet, depending on the position of the flap, is located in front of an end of the electromagnet, slightly towards the pivot flap secured on the bottom of the U.

In a preferred embodiment, the pivot mechanism itself is wholly positioned behind the pivot flap and the flap is not pivoted inside the fork of the frame, as distinct from known display elements, wherein the permanent magnet is positioned beside the pivot flap, in parallel with the plane of the flap, said flap being pivoted inside the fork. By virtue of this, the size and the shape of the pivot flap can be practically independent of the size of the frame.

Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a side view of a display element.

Figures 2, 3 and 4 are perspective views of a fastening frame of the display element, a frame of a coil of an electromagnet, and pivotable member for a pivot flap respectively.

The principal features of the structure and the function of the display element appear from Figure 1. A pivot flap is indicated by the reference numeral 1, a display surface of said flap by the numeral 2 and a background surface by the numeral 3. The numeral 4 generally indicates a supporting piece of the pivot flap, i.e. a frame of the display element; 5 indicates one branch of the frame fork (the other branch 6 being shown in Figure 2); 7 is a foot part or a supporting part of the frame, from the end 8 of which the display element and the connecting wires thereof are secured on a supporting element, usually a card, which is common to a large number of display elements. A pivot pin of the flap 1 is indicated by the numeral 9, a permanent magnet, which is pivoted with said flap, with the numeral 10.The reference numeral 11 designates a coil of the electromagnet and 12 a core of the electromagnet.

One end of the cylindrical electromagnet is secured in one branch 5 of the fork and the permanent magnet 10 extends between the other, free end of said electromagnet and the opposite branch 6 of the fork, being slightly towards the pivot flap with respect to the axis of the electromagnet. Said flap 1 is pivotable from a display position, shown by continuous lines in Figure 1, to a background position, shown by dotted lines, by reversing the polarity of the magnetic field of the electromagnet by means of a short current pulse so that said electromagnet repels a pole 10a of the permanent magnet, whereby a force pulse is directed to said pole 10a, under the influence of which pulse the flap 1 is pivoted from the display position to the background position, in which it is maintained by virtue of the attraction between the core of the electromagnet and the permanent magnet, until the polarity of the magnetic field is again reversed so that it repels a pole 10b of the permanent magnet.

Figure 2 is a more detailed view of the frame of the display element. The numerals 13 and 14 designate bearing openings; 15 is an opening for fastening of the electromagnet; 16 and 17 being abutment surfaces for limiting the pivoting movement of the flap 1.

Figure 3 shows the frame 18 of the coil of the electromagnet, the end of which is provided with a pin 19 to be inserted in said opening 15, whereby the core 12 of the electromagnet is positioned in the central cavity of said frame.

A pivotable member of the pivot flap 1 is shown in Figure 3 and is generally indicated by the reference numeral 21. Roughly, said pivotable member has the shape of a broad U, whereby the pivot flap 1 is secured on the outer surface of the bottom 22 of the U, and the pivot pins 9 extending into the bearing openings 13 and 14 are positioned in the side portions 25 of the U. The permanent magnet 10 is fitted in a holder 23, outside of which one branch 25, with pivot pin 9 can be positioned; alternatively, the pivot pin 9 can be directly joined to said holder 23 which thus forms a side portion of the U. A plate 22 forming the bottom of the U extends to some extent beyond the holder of the permanent magnet, thereby forming a flange 24 for limiting the pivoting movement.

In the case shown in the drawing, the holder 23 of the permanent magnet is positioned adjacent the branch 6 of the frame fork, whereby the end 24a of the flange 24 hits the abutment surface 17, when the flap is pivoted to the display position.

The embodiment of the display element shown in the drawings, Figures 2 to 4 in particular, can be regarded as a preferable one, but embodiments are not restricted thereto; the details can be modified without deviating from the principal features of the structure according to Figure 1. An important feature of said structure is that only the pivotable member with the permanent magnet is pivoted inside the fork 5, 6, whereas the pivot flap 1 itself moves outside the outlines of said fork 5, 6, whereby said fork does not restrict the size and the shape of the flap 1. Thus, the permanent magnet can be secured to the pivotable member 21 in some other way than by means of the holder 23 and the permanent magnet does not necessarily need to be adjacent the pivot axis 9. The permanent magnet can also be semicircular.A short electromagnet could be placed in a vertical position along the fork branch 6, whereby the permanent magnet would rotate above the electromagnet.

It is also to be mentioned that the display element is shown in the drawing on an enlarged scale. The inner width of the fork 5, 6 can typically be about 3 cm. Besides dot matrices of different sizes, the frame 4 is also suitable for segment displays of different sizes, even for large, so called 16segment displays. Controlling of the display ele menus is effected in a known manner; it is therefore unnecessary to describe it more closely here.

Modifications to the specific embodiments described herein and to any broad aspects thereof re erred to or suggested herein may be apparent to those skilled in the art and the disclosure hereof is intended to encompass any such modifications.

The claims presently appended hereto define those aspect(s) for which protection is being sought for the time being.

Claims (7)

1. A display element comprising a flap mounted in a forked portion of a frame to be movable between a display position and a background position; a permanent magnet movable with said flap; and an electromagnet stationarily mounted adjacent said permanent magnet, the movement of said flap being effected by reversing the polarity of the magnetic field of the electromagnet to that adjacent poles of the permanent magnet and the electromagnet repel each other, wherein the flap and the permanent magnet are mounted on a pivotable member mounted in the forked portion of the frame, the pivotable member being of such dimensions that the flap in the two positions and during the pivoting movement thereof is outside of the outlines of the forked portion viewed in the direction of the pivot axis of the pivotable member.

2. A display element as claimed in claim 1, wherein said pivotable member at least roughly resembles a broad U, whereby the flap is secured on the outer surface of the bottom of the U, pivot pins being fitted in the side portions of the U, and wherein the permanent magnet is positioned adjacent one said side portion.

3. A display element as claimed in claim 2, wherein one end of the electromagnet is mounted on one branch of the forked portion to extend substantially parallel to the pivot pin of the pivotable member, the permanent magnet comprising an elongate member of such dimensions that in the display position of the flap one end of said elongate member is positioned between the free end of the electromagnet and the adjacent branch of the forked portion, slightly towards the pivot flap with respect of the axis of the electromagnet, and in the background position of the flap the other end of the elongate member is likewise positioned.

4. A display element as claimed in any preceding claim, wherein the pivoting movement of the flap is limited by the abutment of surfaces provided on the forked portion with an abutment member provided at one end of the pivotable member.

5. A display element as claimed in claim 4, wherein said abutment surfaces are in line with the outlines of the forked portion viewed in the direction of the pivot axis.

6. A display element as claimed in claim 4 or 5, wherein said abutment member comprises a flange of the pivotable member.

7. A display element substantially as hereinbefore described with reference to the accompanying drawings.