[0001] This invention relates to an improved information display apparatus, more particularly
but not exclusively to visual information display apparatus.
[0002] Various types of information display apparatus are known in which images are formed
by selectively displaying an appropriate face of one or more character forming elements.
The elements are actuated to change their image by electromagnetic means. One such
apparatus is described in the Applicants British Patent Application Number 2189067A.
[0003] In the prior art apparatus, the image forming elements are mounted to rotate in a
framework to display coloured elements against a contrasting background. However,
these apparatus have the disadvantage that the elements are so arranged such that
an inadequate contrast ratio is obtainable between the coloured elements and the contrasting
background of the frame which limits the clarity of the resulting character image.
A further disadvantage of this arrangement is that the character frame limits the
generation of pictorial image information and creates difficulties when multi-lined
or a mixture of large and small characters is required.
[0004] An aim of the present invention is to provide an improved information display apparatus
which overcomes the disadvantages of the prior art constructions and enables the rapid
formation of accurately formed images and individual characters.
[0005] According to the present invention, there is provided an information display apparatus
comprising a frame in which are mounted a plurality of movable elements having at
least two display areas, and an array of activating means, the frame of elements and
the array of activating means being movable relative to one another such that on selective
energisation of the activating means, one or more of the plurality of movable elements
are moved to create a changeable display of information, wherein the frame is a matrix
of rectangular apertures in which are rotatably mounted correspondingly shaped rectangular
elements which are positioned closely adjacent one another.
[0006] Conveniently, the frame is a wire matrix, the rectangular shaped elements being rotatably
mounted on adjacent vertical wires of the matrix.
[0007] In an alternative arrangement, the frame is made as a moulded plastics construction.
[0008] Preferably, the array of activating means is mounted in a carriage including a framework
of roller elements to guide a plurality of linear elements away from and return them
into engagement with the rear surfaces of the rectangular elements to maintain the
elements in a selected aligned formation.
[0009] An embodiment of the improved display apparatus, according to the invention, will
now be described with reference to the accompanying drawings in which:
Figure 1 is a diagrammatic elevation of a frame unit carrying a matrix of elements;
Figure 2 is a diagrammatic side elevation of the frame unit of Figure 1 and the array
of activating means and;
Figure 3 is a diagrammatic plan view of the frame unit and array shown in Figure 2.
[0010] The improved display apparatus comprises a frame unit generally indicated at 1 including
a wire matrix 2 forming a plurality of adjacent rectangular apertures 3. Pivotably
mounted on adjacent vertical wires 4 separated by horizontal wires 4
a of the matrix are rectrangular elements 5 having a corresponding shape to the apertures
3. Each element 5 is made from a soft magnetic material having a low remanence and
has two contrasting surfaces which may be of a fluorescent sheet material or coated
with another suitable material e.g. paint.
[0011] The wire frame units are mounted in a display area such that the elements are rotatable
about their vertical axis by the passage of a carriage carrying the array of activating
means illustrated in Figure 3. The carriage comprises a bank of seven solenoids 6
arranged vertically, one above the other with their respective armatures 7 positioned
directly behind a rotatable element 5. Mounted on the front of the bank of solenoids
are two brushes 8 and 9. According to the direction of the activating means, the leading
brush straightens the element if it is out of position, prior to energisation of the
element and the trailing brush gently pushes the energised element from 90 degrees
to 180 degrees to reverse its position.
[0012] A printed circuit board 10 connected by electrical wires 11 to the bank of solenoids
is mounted on the carriage and carries a reflective sensor 12 at its forward end.
The sensor acts to determine the position of each element 5 as the carriage passes
along the frame of the element.
[0013] In order for the sensor position and activating means position to be known relative
to the movement of the activating means, timing markers 16 are conveniently positioned
along the track of the activating means, which, by means of a slotted opto electronic
device 17, generate timing pulses. These timing pulses control the point at which
the sensor reads the position of the element and the activating means on/off time.
In the drawings, the elements 16 and 17 are shown moved through 90° to the vertical
for ease of reference.
[0014] Passing horizontally along the centre of each row of elements 5 is a control line
13 which is tensioned at the ends of the display area to hold the elements firmly
in their selected position. These control lines 13 pass around four vertical guide
rollers, two 14 at the front of the carriage and two 15 at the back. The control lines
are automatically guided around the back of the carriage as it traverses the display
in the direction of arrow 'A' allowing the array of activating means to alter the
elements passing between the two front rollers 14 and return the control line to the
back suface of the arrangement of element 5 of the changed display.
[0015] The improved display apparatus provides an accurately shaped character, e.g. the
letter 'A' in Figure 1, which can be read easily from a close and a far distance.
[0016] Various modifications may be made to the display apparatus of the invention, for
example, the frame may be of a moulded plastics construction instead of a wire matrix.
The movable elements may be manufactured from extruded soft magnetic material, an
extruded material with an integral soft magnetic material or from extruded material
to which soft magnetic material is subsequently assembled.
1. An information display apparatus comprising a frame (1) in which are mounted a
plurality of movable elements (5) having at least two contrasting display areas, and
an array of activating means (6) (7), the frame of elements and the array of activating
means (6) (7) being movable relative to one another such that on selective energisation
of the activating means (6) (7), one or more of the plurality of movable elements
(5) are moved to create a changeable display of information, wherein the frame (1)
is a matrix of apertures (3) in which are rotatably mounted correspondingly shaped
elements (5) which are positioned closely adjacent one another.
2. An information display apparatus as claimed in Claim 1, wherein the frame (1) is
a wire matrix (2), the shaped elements (5) being rectangular and rotatably mounted
on adjacent vertical wires of the matrix (2).
3. An information display apparatus as claimed in Claim 1, wherein the frame (1) is
of a moulded plastics construction.
4. An information display apparatus as claimed in any preceding Claim wherein control
lines (13) pass along the rear surface of each row of movable elements (5) to hold
them in a selected position.
5. An information display apparatus as claimed in Claim 4, wherein the control lines
(13) pass around rollers (14) mounted on a carriage which carries the array of activating
means (6) (7), to remove and return the control lines from engagement with the rear
surface of the activating means (6) (7) to enable the array to traverse and activate
the elements (5).
6. An information display apparatus as claimed in any preceding Claim wherein the
activating means (6) (7) comprises an array of electromagnets (6) which are selectively
energised.
7. An information display apparatus as claimed in any preceding Claim wherein the
movable elements (5) are extruded from a soft magnetic material.
8. An information display apparatus as claimed in any of Claims 1 to 6, wherein the
movable elements (5) are manufactured from an extruded material with an integral soft
magnetic material.
9. An information display apparatus as claimed in any of Claims 1 to 6, wherein the
movable elements (5) are manufactured from extruded material to which soft magnetic
material is subsequently assembled.
10. An information display apparatus as claimed in any proceding Claim wherein leading
(8) and trailing (9) brushes are provided on the array of activating means (6) (7)
to assist in the alignment of the movable elements (5), to prevent the leading brush
(8) air flow disturbing said alignment.
11. An information display apparatus as claimed in any preceding claim, wherein the
activating means (6) (7) are microprocessor controlled to display changeable characters
or images.
12. An information display apparatus as claimed in any proeceding Claim, wherein an
array of sensing elements (12) corresponding to the actuating means (6) (7) are able
to detect the state of the display elements (5) in advance of actuation to correct
errors arising in the display.