GB2431038A

GB2431038A - Multiple image display

Info

Publication number: GB2431038A
Application number: GB0517765A
Authority: GB
Inventors: Roy Booth
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-01
Filing date: 2005-09-01
Publication date: 2007-04-11
Also published as: GB0517765D0

Abstract

A multiple image display comprises two or more images a, b, c each separated into at least two parts a1-4, b1-4, c1-4. The parts are grouped and arranged so that the pieces of any one image a, b, c may move relative to and pass between the corresponding pieces of the other image(s), such that each image can be brought into view by exposing the relevant parts, or can be hidden from view by disposing the image parts behind the corresponding parts of another image. The image parts may be moved using fluid pressure, electric motors, or electromagnetic solenoids, and may be held in position by mechanical locking means. The image parts may be moved as a result of a change in orientation or position of the display, or as a result of angular or linear momentum induced by the acceleration or deceleration of all or part of the display. The display may include an opaque border 1 which can be used to obscure the foremost parts b4, c4 of the front images b, c.

Description

Multiple Image Display This invention relates to a device for displaying

multiple images within a single viewing frame.

There are already a number of technologies in existence for displaying two or more images within a single viewing frame.

One such technology uses rotating triangular louvers which have rectangular slices' of two or three images attached to alternate faces of a triangular column. The viewing frame contains a number of such columns arranged parallel to each other and closely spaced. The columns are rotated synchronously so that two or three complete images are reconstructed from the corresponding image slices' over a period of time.

Although conceptually simple such an arrangement can suffer a number of practical disadvantages. Small spaces need to be provided between adjacent columns to maintain mechanical clearance. To allow for manufacturing tolerances and thermal expansion these spaces are typically sufficiently large as to be visible from a distance and impart a striped' appearance to the observed image.

This apparent striped' effect can become exaggerated by mechanical practicalities such as back-lash and gear wear which result in imprecise alignment of the column faces i.e. the image strips' become non-coplanar.

Mechanical reliability can also be an issue due to the large number of moving parts e.g. gears, belts, chains and bearings. The mechanical complexity often limits the speed at which the columns can rotate and also imparts a cost burden.

Further mechanical problems can exist due to the fact that each column can only be supported at its endpoints. Although these problems can be minimised by arranging the columns vertically instead of horizontally the balance between column stiffness' and weight can become a problem for large signs.

A more fundamental disadvantage of this type of display is the fact that it is limited to a maximum of three different images.

An alternative to the rotating triangular column technology which can display more than three images uses two rollers and a flexible belt' upon which images are printed.

The ends of the belt' are wrapped around the two rollers which are spaced in such a way as to expose one image to the viewing window.

Both rollers are then synchronously rotated a defined number of turns to bring each subsequent image into view.

Unfortunately, reliability problems exist with most practical implementations of this type of technology. These are principally due to manufacturing tolerances, belt' wear and differential thermal expansion which can result in frequent jamming of the belt'.

Also, the rotational speed, acceleration and deceleration of each roller needs to be accurately controlled to prevent the belt' ripping, sagging or jamming.

Furthermore, as more of the belt' moves from one roller to the other this necessitates an adjustment in the relative roller angular speeds to allow for the increase and decrease in roller circumferences.

A much simpler technology exists for displaying multiple images which has no moving parts. Essentially two or more images are separated into very thin strips' and printed in an interlaced manner either onto a backing material over which is placed a lenticular lens or directly onto the back of a lenticular lens which is subsequently covered with a backing material.

The optical geometry of the lenticular lens is such that it selectively makes visible all the strips' from a particular image and hides from view all the strips' of the other images dependant upon viewing angle.

Whilst this type of multi-image technology does not require any power to operate it has a number of disadvantages. The observed images can appear quite blurred' and the technology requires the relative motion of the observer to expose subsequent images.

Also, there exists a number of viewing positions where more than one image is partially visible. The resultant image combinations are often meaningless and confusing. Furthermore, once a lenticular display has been created it is fixed i.e. to update the image content requires the manufacture of a complete new lenticular assembly.

Yet another technology for displaying multiple images in a single viewing frame is based around a television or computer monitor screen. The principle disadvantages to this type of technology are the comparatively high cost, limited size and poor visibility in sun-light.

An alternative technology exists, based around multi-coloured light emitting diodes, which does allow large screens to be constructed which can be used in sun-light. Unfortunately the image quality is relatively poor and the overall cost is relatively high. Although such displays are viewable in direct sun-light they consume relatively large amounts of power, have a relatively narrow viewing angle and an unnatural appearance.

The present invention provides a means of displaying multiple images within a single viewing frame which overcomes the drawbacks associated with the technologies already discussed.

The essential features of the invention are that two or more images are separated into corresponding strips' which are grouped and arranged in such a way that all the strips' of any one image can be made to move relative to and pass between the corresponding strips' of all the other images in such a way that each image can be individually brought into view or fully obscured.

The advantages of such an arrangement are that a low power display means can be constructed which allows multiple images to be presented within a single viewing frame where each image can be of photographic quality, viewable from a wide angle, viewable in direct sunlight and capable of producing continuous flat' images of a natural appearance which can be alternated relatively quickly using comparatively few moving parts.

Preferably the image strips would be oversized i.e. include some overlap and be displaced more than a strip height when activated to ensure any one image completely covers all the remaining images leaving no gaps.

The image strips would preferably be mounted on rigid support frames which would be moved using electric motors although the image strips could also be moved by other means e.g. using pneumatic actuation.

The image strips could also be moved by ambient effects e.g. an inertial mass attached to an operating mechanism could cause a display to change images during the braking action of an automobile.

This invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows three distinct images being separated into horizontal strips and arranged in such a manner as to make visible image c'.

Figure 2 shows the effect after moving all the strips of image c' down one strip height i.e. to reveal image b'.

Figure 3 shows the effect after moving all the strips of image b' down one strip height i.e. to reveal image a'.

Figure 4 shows a piece of a frame used to hold one set of image strips.

Figure 5 shows how two frame pieces of the type shown in figure 4 can be combined to create a section of the overall frame.

Figure 6 shows two carriers' used to hold strips from different images.

Figure 7 shows how the carriers' depicted in figure 6 would engage with the combined frame pieces depicted in figure 5 to produce a section of the overall display.

Figure 8 shows a possible actuator mechanism.

Figure 9 shows the application of multiple actuators to a frame assembly.

Figure 10 shows a possible actuator powered by an electric motor.

Figure 11 shows a possible actuator powered using pneumatic action with a solenoid actuated holding pin.

Figure 1 illustrates three distinct images a', b', and c' being separated into four similar sized horizontal strips numbered.1', .2', .3' and.4' Note for illustrative purposes each image has only been separated into four pieces. In reality each image would typically be separated into a larger number of pieces to reduce the amount of image movement required to operate the display.

Figure 1 also depicts a side view of the arrangement of the image strips from all three source images. Note, the strips are arranged in such a fashion as to reconstruct the original layout of each image e.g. strip al'is positioned above and adjacent to strip a2' which is itself positioned above and adjacent to strip a3' etc. Note however, that each consecutive image strip from a particular image is displaced slightly from its predecessor in a direction perpendicular to the image plane. This displacement provides a channel through which the strips from alternate images can traverse.

With the image strips arranged as depicted in figure 1 the observer can only see strips ci', c2', c3' and c4' and thus observes image c' in its entirety.

However, if each strip of image c' is displaced the equivalent of one strip height in a downwards direction, as depicted in figure 2, the observer can no longer see any of image c' but can clearly see all of image b'.

Similarly, if each strip of image b' is displaced the equivalent of one strip height in a downwards direction, as depicted in figure 3, the observer can no longer see any of images b' or c' but can clearly see all of image a'.

Note, an opaque border, labelled (I) in the figures, is necessary to obscure strips b4' and c4' when they are displaced downwards.

Thus by arranging strips of several images in a manner such as that depicted in figure 1, any image can be either brought into view or completely hidden from view simply by applying a small common displacement to each strip of the selected image.

Note: the slight separation of consecutive strips from each image introduces a gradient to the image plane. However, providing the ratio of strip-height to strip-separation is at least 4:1 the angle of the gradient will be less than 15 degrees. If necessary this gradient can be eliminated by applying a contra rotation to the image plane.

To produce a display system based upon the current invention a means of supporting and selectively moving all the strips' of one image with respect to all the strips' of the other images is required.

Figures 4. .9 illustrate an example of one possible implementation of such an arrangement.

Figure 4 depicts a shaped piece of sheet material (2), typically made from metal or plastic, which has a number of slots (3) cut into one face and an area

to support a strip' of a background image (4).

Figure 5 illustrates how sections such as those depicted in figure 4 can be joined together to create a means of supporting successive strips' of a background image (4) in such a manner as to recreate the original layout of the image but with a small separation in a direction perpendicular to the plane of the image.

Figure 6 depicts two types of image-strip-carriers' (5) and (6), typically made from a strong sheet material e.g. steel, which have extended support legs' arranged in distinct patterns.

To construct a section of the example three image display a strip' of one image is attached to the background area (4) and a corresponding strip' from each of the other two images is attached to each type of image-stripcarrier' (5) and (6). The image-strip-carriers' are then inserted into the frame section as depicted in figure 7.

Note: the support legs of the image-strip-carriers' align with the slots (3) cut into the horizontal face of the background image support sections (see figure 4) and allow the image-strip-carriers' to slide into position behind the

corresponding background strips.

Once all sections of the display are assembled only the background image strips will be visible. To make either one of the other two images visible requires that each image-strip-carrier' of the selected image be raised a distance equivalent to the image strip height.

One possible means of achieving this is to construct actuators of the type shown in figure 8. The actuator is made up of a piston (7) which is free to slide inside of a housing (8). Slots (9) formed in the actuator housing allow the image-strip-carrier' support legs to pass through the housing and engage with the moving piston.

The lower illustration of figure 8 shows an assembled actuator with the legs of four image-strip-carriers' (5) inserted and engaged with the piston (7).

When the piston is driven upwards it causes the support legs of each selected carrier to move up. When the piston is lowered it pulls each support leg back down.

The different support leg arrangement of the two types of image-stripcarriers' (5) and (6) allows actuators to be positioned so that they engage with either one or the other type of image-strip-carrier'.

Figure 9 illustrates a rear-view of a complete display assembly using the components described above. With all actuators in the de-activated state the

display will show the background image.

To make one of the alternate images visible simply requires the actuation of just those actuators associated with the image-strip-carriers' of the required image.

Figure 10 depicts a simplified drive arrangement for an actuator using an electric motor (9) (e.g. a stepping motor) and a gear drive (10). Optional piston position feedback sensors (11) could be utilised to ensure the piston (7) is driven fully from one state to the other.

Figure 11 depicts an alternative actuator arrangement which uses air pressure under the piston (7) to create lift'. An optional solenoid actuated locking mechanism (12) could also be utilised to allow the piston (7) to be held in position after the air pressure was released.

In a display using actuators of the type shown in figure 11, each actuator common to a particular set of image-strip-carriers' would be fed with pressurised air. The locking mechanisms (12) of each actuator would then be released to allow the air pressure to lift the selected pistons. The locking mechanisms would then be re-engaged with the pistons in the raised position thus allowing the air pressure to be released.

Such an arrangement would enable a very fast snap-like' actuation which would give the visual impression of one image changing almost instantaneously into another.

Note that the number of actuators required for a display is determined by the width of the image-strip-carriers' and the strength of the material used for their construction. For a relatively modest width display it would be feasible to use actuators only at the ends of the image-stripcarriers'.

Note also that the example proposed above could easily be extended to display more than three images simply by providing extra sets of imagestrip- carriers' with a different support leg arrangement and associated actuators.

Claims

Claims I A multiple image display means whereby two or more images are

separated into two or more corresponding pieces which are grouped and arranged in such a way that the pieces of any one image can be made to move relative to and pass between the corresponding pieces of the other image(s) in such a way that each image can be individually brought into view or hidden from view.
2 A multiple image display means according to claim 1 whereby the image pieces are moved using fluid pressure.
3 A multiple image display means according to claims I and 2 whereby the positions of the image pieces are maintained using a mechanical locking means.
4 A multiple image display means according to claim 1 whereby the image pieces are moved by one or more electric motors.
A multiple image display means according to claim 1 whereby the image pieces are moved by electromagnetic solenoid action.
6 A multiple image display means according to claim 1 whereby the image pieces are moved as a result of a change in orientation or position of the display means.
7 A multiple image display means according to claim I whereby the image pieces are moved as a result of a change in either angular or linear momentum induced by the acceleration or deceleration of all or part of the display means.