Background Art Methods and apparatus for the presentation of objects based on the principle of contrast are known. Hungarian Patent No. 206923 discloses a signal displaying element with a magnetic tilting plate. The magnetic tilting plate has two sides, where one side is preferably black, while the other side has a light, well visible colour, e. g. yellow. The plate has two states, so that in a first state the black side of the plate is visible, while in the second state the yellow side is visible. Positioned before a black background, the element is practically invisible in the first state, while providing a well visible dot if it is tilted in the second state by an appropriate electromagnet. This known element is used as a pixel in a larger signal board, mainly used in railway stations, airports, and similar public places, where often changing information must be provided to the public with large and well visible letters and numbers. The displaying element based on this principle operates relatively fast, but requires significant amounts of energy. Also, the mechanism is relatively bulky.

There are certain cases when there is need for the presentation of various visual objects, mostly two-dimensional ones, in a manner so that the objects seem to appear and disappear without any obvious mechanism guiding their appearance or disappearance. Such effects may be readily produced by known electronic displays controlled with appropriate microprocessors, but in certain applications the use of the known cathode ray tubes or LCD-matrix displays or other known dynamically changing displays are not feasible. E. g. in the art of watch-making, it is often desirable to present objects for a certain time only, and then letting them disappear.

Typical examples are miniature symbols of the sun and the moon, which are painted on a small rotating disc built into the face of the watch, and which seem to appear from and disappear behind an artificial horizon. Normally, this"horizon"is formed as the edge of a slot on the face of the watch. As the disc rotates, the figures of the sun and the moon appear and disappear in the slot. It is preferred to utilise a mechanical solution for the dynamic presentation of the objects on the face of the watch, due to obvious reasons. The rotation of a small disc needs extremely little energy, and the rotating movement is inherent in the clock mechanism, so the dynamic visual effects based on this rotational movement are easy to realise.

However, these known solutions are not always suitable. Especially with designer watches there is a tendency to produce constantly changing decoration, especially some type of graphic, on the face of the watch. It is desired to achieve this change in a puzzling or intriguing manner, e. g. in a way so that the change of the graphic is not a result of an obvious displacement of a visual object, e. g. the result of a movement of a distinct motive of the graphic. In most cases the simple displacement, i. e. translation and rotation of a motive is readily identified by the observer, mostly due to the overlapping edges of the different, distinct motives, or simply by the easily recognisable movement of a motive itself. If the reasons of the change are easily identified by the observer. the change of the graphic loses its puzzling character, and its decorative value is negatively affected.

Further, it is a general disadvantage of the known solutions that the scale of the movement necessary for the complete appearance or disappearance of a certain object is in the same order of magnitude as the physical dimensions of the object itself. E. g. in order to hide an object. e. g. a circle completely, the whole circle must be moved behind a cover or before a background with the same colour, so the circle must be moved at least as much as its diameter.

Therefore, it is especially desirable to produce the appearance or disappearance of certain motives in a manner so that the motives themselves do not seem to move at all, or truly do not move, but simply appear and disappear"out of the blue".

Therefore, it is an object of the invention to provide a method and apparatus for the presentation of objects which is easy to implement with a simple mechanism, and which is especially suitable for realising it on a very small scale, e. g. in a wristwatch.

It is a further object to provide a method for letting objects appear and disappear without apparently moving the objects, or at least moving the objects in an inostensible manner, where the movement is not apparent for the superficial observer. Especially, it is an object of the invention to provide a method for the dynamic presentation of objects where the magnitude of the movements associated with the appearance or disappearance of the objects may be kept much smaller than the physical dimensions of the objects themselves.

Summarv of the Invention According to the invention, the above objects are achieved with a method, where a coloured two-dimensional object is positioned before a coloured background, and the dynamic appearance or disappearance of the object is achieved by moving the object and the background relative to each other. In the method of the invention the following steps are performed:

a, applying the same exact colour and essentially the same visual surface structure in a first region covering at least a part of the object and in a second region covering at least a part of the background, and b, providing a third region on the object and/or the background with a colour intensity and/or saturation and/or hue different from that of the first and second regions, and further providing a continuous intensity and/or saturation and/or hue transition region between at least one of the regions and the third region, c, positioning the first, second and third regions adjacent to each other, and d, causing the disappearance or appearance of at least one borderline section between the regions by moving the first or second region relatively to each other and relatively to the third region and the transition region, and thereby creating or extinguishing an intensity and/or saturation and/or hue contrast along a borderline between the regions and the transition regions.

Here and in the following description, the tenns"intensity","saturation"and"hue" refer to the commonly used tenns defining the properties of colours. Intensity is the amount of the energy radiated from a unit area on the object. In this regard, a completely white surface has the highest intensity (usually normed to unity), while the intensity of a completely black surface is zero. Saturation defines the amount of the grey or white components of the colour, while the hue refers to the narrow-band spectral equivalent of the basic or dominant colour of a colour having several spectrally different colour components. Though basic colours are defined differently in the different colour systems, the definition of the basic properties of colours are made with these parameters in all commonly used colour systems. Throughout the description, the tenn"different colour"means that the referred colours have at least one different colour parameter. E. g. two colours are regarded different even if their hue is the same, but their saturation is not, e. g. light green and deep green. In this case the peak of their spectrum is on the same wavelength, but the other spectral components of the lighter colour have higher relative intensity (the spectrum is

flatter or broader with less saturation, and the spectrum is sharper with higher saturation.

It will be understood that the terms"object"and"background"are relative terms, and freely interchangeble, according to definition. Normally, the invention is intended to be used with two-dimensional, i. e. planar objects, where the object and the background are essentially in the same plane, apart from the physical requirements of the specific realisation. Generally, the object is defined as being closer to the observer, and covering a part of the background, which latter is further away from the observer. Otherwise these two entities perform their functions together, by providing a clearly visible or invisible borderline between them, where the visibility or invisibility of the borderline is based on visually perceived contrast.

With the provision of a continuous transition region between the two distinct, differently coloured regions, there will be no edge, and hence no distinguishable borderline between the first, second and the third regions, and therefore the observer is not able to identify a reference point relative to which the movement of the first or second region may be perceived. Therefore, if the movement itself is not detected by the observer (e. g. due to its slownesss), the complete impression of the image consisting of the object and the background will seem to change without apparent reason. This effect is especially significant if the actual movement of the object is relatively slow, e. g. as slow as the minute-hand of a clock. Of course, the displacement of the object relative to the background will be realised after a while, but the observer will not see an"incomplete"or"truncated"image, e. g. a half-cut moon, from which the underlying mechanism of the change will be apparent for the observer, and therefore the image is not any more considered to be puzzling or intellectually stimulating. Due to the absence of a well-defined borderline between the regions, the object will appear to"dissolve"into a region of the background, or vice versa, instead of conveying the feeling of incompleteness of a truncated motive.

In an especially advantageous realisation of the method according to the invention. the method includes the steps of providing a fourth region on the object or the background having the same exact colour as the third region, and further providing a continuous intensity and/or saturation and/or hue transition region between the first or second regions and the fourth region, so that there are provided two substantially equal coloured and equal sized transition pattern comprising the coloured regions and the transition region, one transition pattern on the object and one transition pattern on the background, and further positioning the object relative to the background so that at least a part of the object and the background appear indistinguishable from each other. In this case the important effect of the simultaneous appearance or disappearance of a larger part of the object or the background may be achieved, and, most importantly, the simultaneous appearance or disappearance involves only a small movement, compare with the full dimensions of the affected part.

In this case it is especially advantageous to include the steps of covering the visible part of the object and/or the background completely with the coloured regions and the transition, so that the complete object or background is indistinguishable from the other, and causing simultaneously the appearance or disappearance of the complete borderline between the object and the background by moving the object and the background relative to each other.

The invention also relates to an apparatus for the presentation of a two-dimensional object, especially for the performing of the method according to the invention. The apparatus comprises an object positioned before a background having substantially the same visual surface structure and colour as the object, and further comprises means for moving the object relative to the background. According to the invention at least a part of the background is provided with a coloured first region, and at least

a part of the object is provided with a coloured second region, the second region having the same exact colour as that of the first region, and further the object and/or the background is provided with a third region having a colour intensity and/or saturation and/or hue different from the first and second regions, and further there is provided a continuous intensity and/or saturation and/or hue transition region between at least one of the regions and the third region.

Advantageously, the object is provided with an opening, and the background is positioned so as to be visible through the opening. The decorative effect conveyed by the apparatus may be further enhanced if there are provided several layers of objects, so that at least one of the objects is functioning as a background for an other object.

The apparatus of the invention may be used especially in watches and clocks. In an especially preferred embodiment, the background and/or object is formed as the dial-plate of a watch, and the movable object and/or background is rotated relative to the dial-plate. The simple structure of the apparatus is ideally suited for adaptation into small clocks, like wrist-watches. The apparatus of the invention performs the dynamic presentation of objects with an extremely small energy, and therefore do not present a great load on the clock mechanism.

Other advantageous embodiments include the use of the apparatus in advertising signs, jewellery items, theatre and/or cinema stage scenery, sculptures, paintings or similar visual art objects.

Brief Description of Drawings By way of example only, an embodiment of the invention will now be described with reference to the accompanying drawings, where Fig. la-b shows schematically the working principles of the method of the invention,

Figs. 2 and 3 shows another realisation of the method of the invention, Fig. 4 illustrates the working principle of an improved version of the method according to the invention, Figs. Sa-c shows an alternative way of realising the version of the method, based on the analogous principle to that shown in Fig. 4, Fig. 6 illustrates the application of the apparatus of the invention in a wristwatch, Fig. 7 is a perspective view of an enlarged detail of the apparatus shown in Fig. 6, and Fig. 8 is the detail of an other embodiment of the apparatus of the invention.

Best Mode for Carrvins out the Invention Figs. la and lb illustrates the underlying principle of the method according to the invention. Figs. la and lb are identical, the only difference is that no reference signs and explanatory lines are used in Fig. Ia, so that the visual impression should not be disturbed. Here three coloured, two-dimensional hexagonal objects 1 are positioned before a coloured background 2. The dynamic appearance or disappearance of the objects 1 is achieved by moving the objects 1 and the background 2 relative to each other, as will be explained below.

The objects 1 are coloured evenly in a first region 3 covering essentially the whole objects 1.

The background 2, which here is formed as an elongated rectangle, is divided into a darker second region 4, a lighter third region 5, and a transition region 6 between the second region 4 and the third region 5. The second region 4 and the third region 5 are differently coloured, where the difference in the colour must be applied in a broad sense, so the difference may mean any difference in the intensity, saturation or hue of the colours of the regions. It must be noted that e. g. two different shades of green are here regarded as different colours. Also, the regions may not necessarily

be lighter or darker relative to each other, they may have the same intensity, if only the saturation or the hue of their colours are different. With other words, there must be a visual difference in the colours of the second region 4 and the third region 5.

In Fig. 1, the colouring is even within the second region 4 and the third region 5, i. e. all points within a region have the same colours. However, with other embodiments, as will be shown e. g. in Figs. 4 and 5, the colours within the regions may vary. The only requirement is that regions 4 and 5 must be visually different in the sense that the colour of any point or area within the second region 4 must be different from the colour of any point or area within the third region 5.

Between second region 4 and third region 5 there is provided a transition region 6.

This transition region 6 has a finite borderline 7 with the second region 4 and an other finite borderline 8 with the third region 5, and the transition region 6 is coloured such that there is a continuous colour transition between the second region 4 and the third region 5. The continuous colour transition includes all necessary intensity and/or saturation and/or hue transitions between the colour of the second region 4 and the third region 5, so that the borderlines 7 and 8 are actually not visible, as it is perceived in Fig. lb, because there is no sharp contrast on the two sides of the borderlines 7 and 8. Further, the term"continuous transition"also means that there is also no other visible borderline when going from the second region 4 towards the third region 5 or vice versa.

The first regions 3 on the objects 1 has exactly the same colour and essentially the same visual surface structure as the second region 4 of the background 2. The exactly same colour and the essentially same visual surface structure means that the first region 3 and the second region 4 can not be distinguished from each other as perceived by a human eye.

According to the invention, the first region 3, the second region 4 and third region 5 are positioned adjacent to each other, so that a finite section 9 of the borderline 10 between the first region 3 and the second region 4 visually disappears, due to the absence of a visible contrast between the first region 3 and the second region 4.

Now when the object 1 is moved towards the third region 5, the invisible section 9 of the borderline 10 becomes visible, and thereby the complete borderline 10 will be visible. The observer now will be able to realise that the object 1 is a separate entiez from the background 2, and will perceive it as such. Obviously, if the object 1 is moved in the other direction, so that the second region 4 will surround the object 1 completely, than the complete borderline 10 will be invisible, causing the total disappearance of the object 1.

In the method shown in Figs. la and lb the object 1 is translated relative to the background 2. It must be emphasised that the relative movement of the object 1 and the background 2 may be done by rotating as well. This latter is illustrated in Figs. 2 and 3. Here, the objects 11,12,13 are positioned before the background 14. The structure of the background 14 is similar to that of the background 2 shown in Fig.

1. The objects 11,12,13 are identical, and they are each composed of a C-shaped, white part 15 and a hexagonal dark part 16. Fig. 2 shows the effect of the disappearance of the C-shaped part 15 as the object 13 is moved with a translating movement (symbolised by the objects 12 and 11) towards the lighter region of the background 14. The translating movement will result in the transformation of the C- shaped part 15 into the hexagonal part 16, as perceived by the observer. Both parts will be visible in the transition region, as shown with the object 12.

Compare with Fig. 2, Fig. 3 illustrates how the complete objects 11 and 13 will be visible to the observer by rotating the objects 11, and thereby moving the invisible parts to from a non-contrasting region of the background 14 to a contrasting region.

Turning now to Fig. 4, an other, especially preferred realisation of the inventive method is illustrated. Here, the objects 21, 22, 23 are positioned before the background 24. There is provided a first region 26 on the objects The structure of the background 24 is similar to that of the backgrounds 2 and 14 in Figs. la, lb, 2 and respectively. The background 24 comprises the second region 27 and

the third region 28, being differently coloured from each other. There is provided a transition region 25 on the background 24, which creates a colour transition between two differently coloured regions. The borders of the regions are partly indicated by the dotted lines on the top and bottom of the frame, representing the borderlines 7 and 8. It must be noted that in the most preferred realisation of the method, as illustrated in Fig. 4, the differently coloured regions themselves are provided with a transition, so practically the whole background 24 is covered by a larger integral or continuous transition pattern, which here includes all three regions 25,27 and 28.

Alternatively, if not the complete background, than at least the whole area used during the method should be covered by the continuous transition region.

The most important improvement of the inventive method is the provision of a fourth region 29 on the objects 21,22,23 having the same exact colour as the third region 28 of the background 24, and the provision of a continuous transition region 30 between the first region 26 and the fourth region 29. As before, the transition includes all the necessary intensity and/or saturation and/or hue transitions for creating a smooth, contrast-free transition from the first region 26 to the fourth region 29 across the whole transition region 30.

It must be noted that in the most preferred realisation of the method, as illustrated in Fig. 4., the first region 26 and the fourth region 29 of the objects 21,22,23 themselves are provided with a transition colouring, quite similarly to the second region 27 and third region 28 of the background 24, so practically the complete objects 21,22,23 are covered by a large integral transition pattern, which here includes first region 26, transition region 30, and fourth region 29. With other words, the objects may be regarded as being completely covered by a transition region, while the first and fourth regions are infinitely small.

It is important to point out that the various regions on the background 24 and on the objects 21,22,23 are arrange and sized in a manner so that there are provided two substantially equal coloured and equal sized transition patterns comprising the

coloured regions and the transition regions. There is provided one transition pattern on the objects 21,22,23 and one transition pattern on the background, so that the objects 21,22,23 may be positioned relative to the background 24 in a manner where they appear visually indistinguishable from each other. In Fig. 4, the object 22 is shown in this position. The object 22 would be perfectly invisible, if its contours were not marked by the dotted line, which indicate the borderline 31.

Now, if the object 22 is moved, e. g. translated to the left or to the right, suddenly and unexpectedly a substantial part of the borderline 31 surrounding the object 22 would become visible, because a visible contrast appears between the two sides of the borderline 31. The objects 21 and 23, which are displaced a little to the left and to the right relative to the object 22, illustrate this effect. Looking at Fig. 4, the object 21 appear darker than its surroundings, while object 23 appear lighter. It must be noted, however, that the colouring of the objects 21,22 and 23 is exactly the same, but the minimal difference in their position is enough to create a well-defined and visible contrast along their borderline, as compared with their"invisible" position. As it is also apparent from Fig. 4, a relatively small movement in the order of a few millimetres is enough to make a substantially larger object appear in its completeness. E. g. in Fig. 4 the objects 21,22,23 are several centimetres in diameter, but their displacement relative to the invisible position is approximately five to ten millimetres. This is due to the extremely high sensitivity of the human eye, which is capable of distinguishing between colours even if the difference is minimal. It must be noted that the eye is most sensible to the differences in intensity, and less to hue and saturation. Therefore, the best results are achieved with the method if the transition region includes also a transition between a lighter and a darker colour, i. e. between colours with a high and low intensity. Of course, the choice of the colours is always dependent on the application environment of the method.

It is most advantageous to cover the visible part of the object and/or the background completely with the coloured regions and the transition. In this case the complete object or background is indistinguishable from the other, and their relative movement will cause the simultaneous appearance or disappearance of the complete borderline between them. The appearance of a complete or closed borderline is translated in the brain as the perception of the object itself, which is enclosed by the closed borderline. So the effect will be the sudden and unexpected appearance or disappearance of a visual object.

Figs. Sa-c shows this working principle, but here the circular object 41 is not translated, but rotated before the background 42. Compared with its invisible position shown in Fig. Sa, the object 41 is extremely well visible as a result of an approx. 150 degree's rotation in Fig. 5b. As it is seen in Fig. 5c, the borderline 43 is perceptible already after a rotation of only 10 degrees.

Fig. 6 and 7 show a possible embodiment of the apparatus according to the invention. The apparatus here is included in a clock, more specifically in a wrist- watch 51. The wrist-watch 51 comprises a dial-plate 52 with a minute-hand 57 and an hour-hand 58. The dial-plate 52 is serving as the object, or more precisely, it is defining the borderlines 53 of the object. For this purpose, the dial-plate 52 includes four circular regions 54. The circular regions 54 have cut-out openings 55 in the form of the Roman numbers III, VI, IX, XII, so that a similarly sized back plate 56 is visible through the openings. One of the circular regions 54 with the associated back plate 56 is shown enlarged in Fig. 7 in an exploded, perspective view. The back plate 56 serves as the background, so for this purpose the back plate 56 is provided with substantially the same visual surface structure and colour as the circular region 54 of the dial-plate 52. The back plate 56 may be rotated around the axis A by an appropriate moving means, in the present case by the clockwork (not shown) of the wristwatch 51. Furthermore, there are identical, continuous colour transition

patterns on the circular regions 54 and the back plates 56, similar to that shown in Figs. 5a-c. In this case the transition pattern is a simple linear transition from a lighter colour to a darker one. If the back plate is positioned behind the circular region in an appropriate position, the borderline 53, in practice the edges of the openings 55, will not be visible because of the missing contrast between the back plate 56 and the circular region 54, and therefore the objects formed by the openings 55 will be practically invisible as well. This situation is illustrated with the circular regions 54 carrying the numbers III, VI, and IX. However, if the back plate 56 is rotated along the common perpendicular axis A, that is away from this position, as shown in Fig. 7 by the arrow B, than the created contrast between the circular region 54 and the back plate 56 will enhance the visibility of the borderline 53 of the openings 55, and the observer will clearly perceive the shape of the numbers punched into the circular regions 54. This effect is illustrated in Fig. 6 on the circular region 54 carrying the number XII.

For example, the clockwork of the wristwatch 51 may include a mechanism for rotating the back plates 56 into a visible position, that is into a position so that the punched numbers are visible, whenever the hour-hand 58 approaches the relevant circular region 54. When the hour-hand 58 of the clock moves away, the back-plate 56 is rotated into an"invisible"position, so that the transition patterns of the relevant circular region 54 and the associated back plate 56 are identically positioned, so they are again indistinguishable, and the contrast along the borderline 53 fades away, and the numbers seem to disappear.

Of course, the apparatus may include several objects and backgrounds within the same embodiment. An example is shown in Fig. 8. Here, the dial-plate 62 of an other watch (not shown) includes three layers. The lowermost layer comprises a back plate 63, provided with a continuous transition pattern. The middle layer comprises an outer ring 64 and an inner plate 65. The outer ring 64 is provided with

twelve square openings 66, through which the back plate 63 is visible, and portions of the outer ring 64 are coloured with transition patterns corresponding to the transition pattern of the back plate 63. The central part of the inner plate 65 is covered by the top plate 67 of the third layer. The top plate 67 and the inner plate 65 are provided with identical transition patterns. The various parts of the arrangement are rotatable around the axis A. This rotation may be done by the appropriate mechanism (not shown) of the watch. For example, the top plate 67 may appear and disappear during its rotation relative to the inner plate 65, while the openings 66 symbolising the hours appear and disappear as the back plate 63 is rotated under them.

It is understood that in such a multi-layer arrangement the roles of the object and the background are relative, and an item functioning as an object may be the background of an other item at the same time.

It is emphasised that the method and the apparatus according to the invention are not intended to be limited to clocks and watches, although the favourable characteristics of the method may be best used in this area. There is nothing in the way for using the method and the apparatus in other fields, like advertising signs, jewellery, cinema and theatre scenery, or in other forms of visual art, especially in the so- called mobile art, for example in the creation of dynamically changing paintings and sculptures.