WO2018060749A1

WO2018060749A1 - Apparatus for decorating the surface of buildings

Info

Publication number: WO2018060749A1
Application number: PCT/HU2017/050037
Authority: WO
Inventors: Pál BARTAL
Original assignee: Bartal Pal
Priority date: 2016-09-27
Filing date: 2017-09-13
Publication date: 2018-04-05
Also published as: HUP1600550A1

Abstract

Apparatus (1) for providing decoration (25) on the surface (2) of buildings. The decoration (25) is represented by pixels (3). The pixels (3) are applied on the surface (2) by means of sponges (7) mounted on supporting elements (5). The supporting elements (5) consist of supporting arms (11) and supporting plates (13). The supporting elements (5) are arranged movably and flexibly between their internal state of rest and their outer active state. The driving mechanism(s) (6) control the outward movement of the supporting element(s) (5) from the housing (4). Sponge (7) of the respective supporting element (5) is loaded with paint and is in contact with the surface (2) for the time of application of the paint.

Description

APPARATUS FOR DECORATING THE SURFACE OF BUILDINGS

The invention relates to an apparatus for decorating the surface of buildings, especially with graphics, advertisements. The decoration is represented by pixels. The pixels are applied on the surface by means of sponges provided with paint, the size of the outer surface of the sponges corresponds to the size of the pixel; the sponges are arranged in a housing having cylindrical or flat lateral faces and are operated by a driving mechanism fixed to a supporting element. During contact of the sponge and the surface the sponge is provided with the required paint through dipping or filling. The distance between the apparatus and the surface is set by a spacer while the position of the apparatus is set by a positioning means in a known manner. The driving mechanism and the positioning means are controlled by a control unit running a program suitable for producing the decoration. The apparatus is forced to move essentially parallel with the plane of the surface.

A mural is a piece of artwork painted directly on a wall, ceiling or other permanent surface in order to decorate them. In a narrow sense murals are painted pictures, such as frescos and seccos, however, nowadays murals include other wall decorating techniques e.g. sgraffito, ceramics, mosaic, stucco, stuccolustro, decorated brick walls and marouflage. In extreme cases graffito, stencilling and giant posters may be mentioned.

Mural artworks are important because they deliver art to public. The costs and the work needed for producing them are considerable. The mural artwork gets much wider publicity than a product exhibited in a gallery. The city can take advantage of the beauty of the artwork.

Patent application HU 64995 describes a method and apparatus for painting walls. In this method the decoration to be painted is applied on the wall by means of sponges soaked with paint. With the present invention various patterns, designs even a photo may be painted on the wall. According to the document HU 64995 only one constantly repeated pattern can be applied on the wall by means of stencil. The paint is applied on the wall by using a spongy paint roller which is continuously coloured by means of a paint brush.

Patent application HU 173732 describes an apparatus for applying paint on a wall. The essence of this document is that the tank of the paint roller is divided into several parts so it can paint different colours side by side. In this manner the adjacent patterns can have different colours while the pattern itself does not change. With the apparatus and method of the present invention any kind of patterns can be produced. If four colours are used then coloured wall printing is possible by using subtractive colour process known in the printing technique.

Patent application HU 144623 describes a wall painting apparatus applicable to paint with different colours. The apparatus has a paint tank divided into several compartments by separation walls. Each of the compartments has a respective paint roller.

Another patent application HU 146545 contains a supplemental solution in which a further embodiment of the apparatus described in HU 144623 is set forth. According to this solution the paint conveying roller is divided into several parts the number of which corresponds to the number of the paint rollers. Each of these parts can freely, loosely move and rotate on a common shaft independently of the others.

The above described solution and also its development can be used for painting a continually repeated pattern on the wall. The novelty of the solution is that the tank of the roller is separated into several parts. According to HU 146545 the separated exact colours applied by the paint roller can be mixed at their contact line by means of paint brushes in this manner even the colours of the rainbow can be painted on the wall. However, only a continuously repeated pattern can be produced on the surface.

Patent application HU 151889 describes a wall painting apparatus suitable for producing different colours. The apparatus is provided with a paint tank divided into several compartments for receiving paints of different materials or colours. Each of the compartments has an opening through which the paint can be fed into interchangeable paint brushes attached to the compartments. The openings can be closed by means of a sliding bolt. According to this solution the exact colours applied by the paint rollers can be mixed at their contact lines with the paint brushes in this manner even the colours of the rainbow can be painted on the wall. But also, only a continuously repeated pattern can be produced on the surface.

Patent application KR 20080028028 describes a wall painting and printing apparatus to paint the wall or digitally print images on the wall with print materials jetted from a nozzle. The apparatus is composed of a printer for printing liquid print material, a Y- axis rail set up in front of the wall, an X-axis rail installed at the Y-axis rail to move up and down and equipped with the printer on the front side to reciprocate the printer in a direction of the X-axis. The apparatus is further provided with a first forward and reverse motor providing power for moving up and down the X-axis rail, a power transmitting unit connected to a shaft of the first forward and reverse motor and the X- axis rail, to move up and down the X-axis rail by transmitting power of the first forward and reverse motor to the X-axis rail, and a driving unit installed at the X-axis rail to reciprocate the printer along the X-axis rail. This apparatus uses nozzles for spraying the paint while in the present invention painting takes place through physical contact. A disadvantage of the solution described in KR 20080028028 is that the nozzles can have a failure frequently; the cost of repairing them is great; the paint needed for painting is expensive; the nozzles may get clogged up, the whole procedure is slower. The present invention is faster, more economic and reliable.

Patent application FR 2735420 describes a computer driven printer which has a moving head carrying an ink- or paint-jet print module. The moving head can be displaced vertically or horizontally under control of the computer, along vertical and horizontal rails. The computer displaces the head in accordance with image data held on the computer. Driving stepper motors move the head along the guides. End-of travel switches stop the head at the limits of travel. A point of reference is associated with one of the corners of the picture. The print module has a single spray jet or three spray jets, one for each primary colour. The duration of delivery of each jet determines the intensity of the colour applied.

A CN 205531233 (U) Chinese utility model describes a full automatic wall materials robot that is under construction, including a backup pad, frames, a work platform, a regulator cubicle and caterpillar base plate, a rotation axis in the backup pad connected with a rotary drive motor. The regulator cubicle is provided with an industrial computer with a touch sensitive screen. This solution uses the inkjet technology for decorating a wall. The apparatuses using inkjet technology are complicated, the nozzles often go wrong and repairing of them is expensive.

Patent application KR 20040012625 describes an automatic wall surface painting apparatus for precisely and easily drawing a special figure such as a picture, character, symbol, logo, etc. on an outer wall of an apartment or high rise building, an inner wall of a building, a road surface, etc. by using an industrial paint composed of C, M, Y, B. The apparatus comprises a main control device having a control function, a paint sprayer for spraying the paint, a conveying roller for bilaterally moving the paint sprayer, a conveying rail for driving and bilaterally moving the conveying roller, a paint sprayer fastening portion fastening the paint sprayer not to be removable or movable by an external force, a paint sprayer connecting device, and a paint sprayer vertical moving device for moving the paint sprayer downward for the next line desired to be painted.

This solution is similar to the one mentioned before, although the detailed realization is not described.

The aim of the present invention is to provide an apparatus which is more economical than the known apparatuses and makes decorating vertical, horizontal, slanting, flat or bossed surfaces of objects with different graphics possible. The apparatus of the present invention eliminates the problems arising from the unevenness of the surface. It has been realized that painting with 'sponge pixels' is simpler, cheaper, less component parts and repair work are needed as opposed to the known solutions. A possible failure can be recognized and repaired easily. The apparatus according to the present invention can be positioned accurately along the X-Y system scaffolding by the known CNC technology and the paint applying elements can be controlled easily. Accordingly, the present invention is an apparatus for decorating the surface of buildings, especially with graphics, advertisements. The decoration is represented by pixels. The pixels are applied on the surface by means of sponges provided with paint, the size of the outer surface of the sponges corresponds to the size of the pixel; the sponges are arranged in a housing having cylindrical or flat lateral faces and are operated by a driving mechanism fixed to a supporting element. During contact of the sponge and the surface the required paint is carried to the sponge through dipping or filling. The distance between the housing and the surface is set by a spacer while the position of the housing is set by a positioning means in a known manner. The driving mechanisms and the positioning means are controlled by a control unit running a program suitable for producing the decoration. The apparatus is forced to move essentially parallel with the plane of the surface. The supporting elements are provided with supporting arms and supporting plates placed essentially perpendicular to the outer end of the supporting arms for holding the sponges in position. The supporting arms of the supporting elements are introduced to the interior of the housing through the wall of the housing and are guided perpendicular to the axis of rotation of the housing or to the lateral face of the housing opposite the surface. The supporting elements are arranged movably and flexibly between their internal state of rest and their outer active state and/or they can be switched between the two positions. The driving mechanism is operated electromagnetically or pneumatically or hydraulically. The driving mechanism(s) are provided with transmitting element(s) in order to ensure axial movement of the supporting arm of the supporting element(s). The transmitting element(s) are arranged in the same axial direction as the supporting arm(s) of the respective supporting element(s) at least at the time of the position change of the supporting arm(s) between their active state and rest state and they communicate with the inner end of the supporting arm(s). Preferably, the driving mechanism(s) control the outward movement of the supporting element(s) from the housing. In order to produce a pixel at least the sponge of the respective supporting element operated by the transmitting element is filled with paint. By switching the supporting element into its active state the sponge is in communication with the surface for the time of application of the paint.

Preferred embodiments of the invention will be defined by the appended claims and the following description.

Detailed description of the invention will be given with reference to the accompanying drawings in which:

Figure 1 a shows the sectional side view of a possible embodiment of the driving mechanism in its state of rest;

Figure 1 b shows the sectional side view of a possible embodiment of the driving mechanism in its active state;

Figure 2 shows the sectional side view of a supporting element provided with sponge; Figure 3a shows the connection between the supporting element and the driving mechanism in their state of rest as viewed from the side;

Figure 3b shows the connection between the supporting element and the driving mechanism in their active state as viewed from the side;

Figure 4 shows a partial side section of an embodiment of the supporting element and the driving mechanism realized as a single element;

Figure 5 shows the side view of an embodiment of the apparatus having a cylindrical housing and its provision with paint where the sponge gets in its active state only when it faces the surface;

Figure 6 shows the side view of an embodiment of the apparatus having a cylindrical housing and its provision with paint where the sponge gets in its active state before it faces the surface;

Figure 7 shows the perspective view of a portion of the apparatus having a cylindrical housing; Figure 8 is a perspective view of a portion of the apparatus embodied with segments of a cylinder;

Figure 9 shows a portion of the apparatus having a prismatic housing as viewed from the side;

Figure 10 shows the rear view of a portion of the apparatus having a prismatic housing without its rear cover;

Figure 1 1 shows a possible arrangement of the apparatus placed on the scaffolding and moved by the positioning means; and

Figure 12 shows the perspective view of the apparatus of Figure 8 provided with a step motor.

The invention is a technology for wall painting by means of which a large surface can be painted quickly and cheaply. The large surface may be an indoor or outdoor flat wall surface, road, etc. However, the surface does not need not to be flat. It may be even slate roof, tiled roof or any other not flat surface. Painting is performed on the basis of a digital image. The method used is inexpensive as cheap paint can be used and painting can be carried out quickly.

The apparatus 1 according to the invention is suitable for providing some kind of decoration 25 e.g. graphics, advertisements on the surface 2 of structures (Figure 1 1 ). The structure may be the wall of a house, a road or any other suitable architectural objects. The decoration 25 is represented by pixels 3. The pixels 3 are applied on the surface by means of sponges 7 having cylindrical or prismatic side walls, the size of which corresponds to the size of the pixel 3. Naturally, the sponges 7 may be made of any kind of material which is suitable to receive and deliver the paint. The sides of the sponges 7 opposite the surface 2 are provided with the required paint through dipping or filling. The paint is filled e.g. into tank 19. The required paint is applied from tank 19 on sponges 7 by means of paint roller 20 controlled by a stripping roller 23 (Figures 5 and 6). Advantageously, sponges 7 are arranged in housing 4 having a cylindrical side wall (Figures 5 - 8) or flat side walls (Figures 9 and 10). The sponges 7 are mounted on supporting element 5 (Figure 2) so that one of their flat sides faces the surface 2. Sponges 7 may be secured to supporting element 5 in a releasable manner e.g. by means of Velcro, or using some adhesive, permanent magnetic binding or by using press studs. Supporting element 5 can be moved perpendicular to the flat side of sponge 7 opposite surface 2 by means of driving mechanism 6 (Figures 1 a, 1 b, 3a, 3b). The distance between sponge 7 or housing 4 and surface 2 is set by a spacer 8 (Figures 5 - 8, 9 and 10) while the position of them is set by positioning means 9 in a known manner. The driving mechanisms 6 and the positioning means 9 are controlled by a control unit 10 running a program suitable for producing the decoration 25. Preferably, apparatus 1 is mounted on scaffolding 22 (Figure 1 1 ). Vertical movement of apparatus 1 is controlled by positioning means 9 connected to apparatus 1 and horizontal movement of the vertical element of scaffolding 22 is controlled by positioning means 9. Basically, apparatus 1 is forced to move parallel with the plane of surface 2.

Supporting elements 5 consist of supporting arms 1 1 and supporting plate 13 positioned perpendicularly to the outer end 12 of supporting arms 1 1 for holding sponge 7. The supporting arms 1 1 are introduced to the interior of the housing 4 through the wall of the housing 4 and they can be moved flexibly between their internal state of rest and their outer active state by means of driving mechanism(s) 6 (Figures 2 and 4).

The driving mechanism is operated electromagnetically or pneumatically or hydraulically to ensure axial movement of the supporting arm 1 1 of the supporting element(s) 5. (The Figures show only the electromagnetically operated driving mechanism 6, the pneumatically or hydraulically operated solution is well within the knowledge of those skilled in the art.) The driving mechanism 6 is in communication with the inner end 15 of supporting arm 1 1 through a transmitting element 14. Preferably, the driving mechanism 6 controls the outward movement of the supporting element 5 from the housing 4. Supporting element 5 can be moved back to its state of rest for example by means of spring 27 (Figures 3a, 3b, 4). In order to ensure proper movement of the supporting element 5 the transmitting element(s) 14 of the driving mechanism 6 are arranged in the same axial direction as the supporting arm 1 1 of the respective supporting element 5. In case of a cylindrical housing 4 the transmitting element 14 and the supporting arm 1 1 are in the same axial direction only for an instant, namely just then when the housing 4 reaches this position during rotation. The supporting elements 5 are arranged perpendicularly to the axis of rotation 16 of housing 4 (Figure 8) or to the lateral face 17 of the housing 4 facing surface 2 (Figures 9 and 10). To provide a certain pixel 3 at least the sponge 7 of supporting element 5 facing surface 2 and operated by transmitting element 14 is loaded with paint. Transmitting element 14 pushes sponge 7 against surface 2 for the time during which the paint is applied. In case of using a cylindrical housing 4 loading the sponges 7 with paint can be done by simply rotating housing 4 and paint roller 20 together. When a prismatic housing 4 is used the supporting element 5 is advantageously provided with a duct 18, however, the sponges 7 may also be loaded with paint by means of paint roller 20.

Driving mechanism 6 shown in the Figures is a solenoid the coil of which is fixed within the housing 4 while the transmitting element 14 represents its iron core (Figures 1 a, 1 b). The solenoid is controlled so that it ensures axial movement of supporting arm 1 1 of supporting element(s) 5 and outward movement of the supporting element 5 from the housing 4. Driving mechanism(s) 6 are positioned in the housing 4 in such a manner that they can ensure perpendicular movement of supporting elements 5 to the surface 2. In the embodiment shown in Figure 4 transmitting element 14 and supporting arm 1 1 are combined to form a single component part which is surrounded by the solenoid coil, which may even be integrated in the housing 4.

In a possible embodiment (Figures 8 and 12) housing 4 is comprised of cylinders with a height of pixel 3 engaged to each other uniaxially (Figures 5 and 6). Basically, at the centre of each cylinder a driving mechanism 6 is arranged. The supporting elements 5 provided with sponge 7 are arranged in the wall of housing 4 basically radially around the driving mechanism 6. Housing 4 is forced to rotate in front of surface 2. Preferably, the speed of progression of apparatus 1 and the peripheral speed of sponges 7 of supporting elements 5 in their active state are chosen to be equal. Apparatus 1 is guided at a distance from surface 2 so that sponges 7 of the supporting elements 5 get in contact with surface 2 when they are moved from their state of rest to their active state and the sponges not being in active state are in their state of rest. (This is shown in Figure 5.) In this case the normal position of supporting elements 5 is the state of rest preferably realized by using elastic support or spring force and they are moved from their state of rest to their active state only when they are in paint position.

In a certain case the supporting elements 5 colouring pixel 3 take up their active position before facing surface 2 similarly to the refill of a ballpoint pen when it is pushed out or retracted. (This is shown in Figure 6.) In this case supporting elements 5 are moved from their state of rest before they come to their painting position and they are kept in active position until pixel 3 is painted on surface 2.

When housing 4 is prismatic, then supporting arms 1 1 of supporting elements 5 are arranged in a matrix through the lateral face 17 of the housing 4 facing surface 2 (Figure 10). Transmitting elements 14 of driving mechanism 6 are connected to supporting arms 1 1 of supporting elements 5. The housing 4 is directed at a distance from surface 2 so that sponges 7 of supporting elements 5 being in active state reach surface 2 but the sponges being in state of rest are at a certain distance from surface 2 (Figure 9).

Scaffolding 22 is essentially adapted for two-dimensional movement since basically perpendicular movement of apparatus 1 or supporting elements 5 to the surface (third dimension) is insignificant. Naturally, apparatus 1 may be placed on a scaffolding 22 ensuring the three-dimensional movement. In this case movement of scaffolding 22 may be controlled in a known manner using CNC control.

In any of the solutions spacer 8 may be an idler. In case of a prismatic housing this solution is not shown in the Figures, here the housing is provided with simple arresters. Then apparatus 1 must be removed from the wall before its next required position is set.

For proper setting of the cylindrical housing 4 a suitable step motor 24 can be used (Figure 12).

The difference between the apparatus 1 according to the invention and a conventional plotter or apparatus using ink-jet techniques is that the paint is not sprayed but applied on surface 2 through physical contact, similarly to painting with hands with a paint roller. For example the invention can be explained so, that it is a paint roller (which is not necessarily cylindrical, it may also be elliptical or prismatic) whose pattern which contacts surface 2 changes according to the design of decoration 25. The superficies of apparatus 1 comprises several sponges 7 mounted on the end of supporting elements 5. Supporting element 5 is moved by means of driving mechanism 6 formed from electromagnet (solenoid) and supporting element 5 is retracted by means of spring 27. Instead of solenoid supporting elements 5 may be moved pneumatically or hydraulically. These embodiments are not shown in the Figures as realizing of them is well within the knowledge of those skilled in the art.

According to one of the embodiments (Figure 5) supporting elements are pushed out at the very instant when respective supporting elements 5 of apparatus 1 exactly come opposite surface 2. A control unit 10 which is a computer system controls the supporting elements 5 of apparatus 1 for painting a pixel 3 on the wall by operating the respective driving mechanism 6. The position of apparatus 1 placed on scaffolding 22 is set by the positioning means 9 for example similarly to the CNC control method (Figure 1 1 ). The size of pixel 3 that is the size of sponge 7 must be selected depending on the size of the given surface 2 and considering the viewing distance. The dynamic range of the human eye is one minute so the size of pixel 3 namely the size of the sponge 7 must be selected according to this.

According to another embodiment (Figure 6) painting of the decoration is different from the above solution in that pushing out of supporting elements 5 does not take place at the very moment when respective supporting elements 5 of apparatus 1 exactly come opposite surface 2 but before they approach surface 2 the driving mechanism 6 pushes out the respective supporting elements 5 similarly to the known 'ballpoint pen mechanism'. Only these pushed out supporting elements 5 will place a pixel on surface 2, the other supporting elements 5 do not meet surface 2. So supporting elements 5 in apparatus 1 are set in their active state or in their state of rest in advance.

If a prismatic housing 4 is employed (Figures 9, 10) then the solution described either in relation to Figure 5 or 6 can be used. In the first case only supporting element 5 must suitably be controlled while in the second case - that is when the required position of supporting elements 5 is set further from surface 2 in advance - apparatus 1 also must be moved in the direction perpendicular to surface 2. It must be removed from surface 2 while supporting elements 5 are set then it must be brought closer so that supporting elements 5 being in active state reach the surface 2. In this embodiment a duct 18 is provided in supporting elements 5 through which the sponges 7 are loaded with paint. The housing 4 of apparatus 1 can be polygonal, oval, it can be a segment of a cylinder or segment of an ellipsoid or it can even have a non-symmetric form.

Considering that the operation executed by apparatus 1 is controlled by control unit 10 the direction of arrangement of a group of pixels 3 (horizontal, vertical, diagonal or optional) is indifferent.

Figures 5 and 6 show the cross-section of one segment of a cylinder 21 forming apparatus 1 of Figure 8 where the driving mechanism 6 is positioned in the fixed middle portion, and supporting element 5 is positioned in the wall of housing 4. During application of the pixels 3 the housing 4 is rotated around the axis of rotation 16. Alongside a plurality of segment of a cylinder 21 are placed monoaxially. A possible embodiment for example contains twelve segments of a cylinder 21 . In this embodiment upon pressing the supporting elements 5 are switched on (Figure 6) and upon a repeated press they are switched off. Thus always the supporting element 5 must be switched over which requires the other state (switched on/switched off) before it reaches surface 2. Switched on means the active state while switched off means the state of rest. In another embodiment only the supporting element 5 facing surface 2 and selected for placing pixel 3 is pushed out for an instant. After placing the pixel 3 the spring force draws it back to its state of rest (Figure 5). As it can be seen in the Figures the iron core of the solenoid presses supporting elements 5 which rotate continuously at a constant speed.

If supporting elements 5 cannot be placed densely enough for ensuring the correct covering then either the paint must be applied on the wall several times starting from a little different position or more painting apparatuses must be arranged after each other.

The stable distance of apparatus 1 from surface 2 is ensured by spacer 8 provided with bearings 26 - in this embodiment a wheel - at the two edges of housing 4 (Figures 5, 6). The diameter of this wheel is selected so that the coloured sponges 7 at the end of supporting elements 5 being in the state of rest do not reach surface 2 - they are at a required distance from it - but supporting element 5 positioned in the active state for painting pixel 3 reaches surface 2. By using another wheel size the distance may be varied depending on the unevenness of the wall but usually 3 mm is satisfactory. The paint is applied to sponges 7 of supporting elements 5 from a tank 19 in which a paint roller 20 is arranged. The required amount of paint on paint roller 20 is ensured by stripping roller 23. Tanks 19 are placed between the wheels and they do not contact them in either direction. The superficies of paint roller 20 takes up the paint from tank 19 and stripping roller 23 is used to adjust the proper amount of this paint. The distance between paint roller 20 and stripping roller 23 can be adjusted. In this manner various settings are ensured for the various requirements (the consistence of the paint, the type of the surface, etc.). The distance between paint roller 20 and sponges 7 of supporting elements 5 can also be adjusted. In a possible embodiment paint roller 20 may be pressed in sponges 7 of supporting element 5. Further, tank 19 is provided with a level regulator for keeping the paint on a steady level.

Moving of apparatus 1 in front of surface 2 is ensured by positioning means 9 for example a CNC machine. One of the positioning means 9 may be coupled directly to apparatus 1 for example the one which provides for the Y-direction movement of apparatus 1 in case of a vertical or horizontal surface 2. The other positioning means 9 provides for the X-direction movement of apparatus 1 . The positioning means 9 may be driven by servo motors or step motors. In one embodiment positioning means 9 also may be provided with elements needed for operating certain parts of apparatus 1 . It may drive housing 4, paint roller 20 and stripping roller 23 and ensures movement in the X and Y direction on the wall. The elements of scaffolding 22 may move in the X and Y direction on rails and for driving them a paired cogwheel-gear rack may be used. These solutions are known in CNC technique. The whole CNC system is controlled by computer software installed in control unit 10. For example apparatus 1 travels in the Y-direction upwards from below then travels back takes a step in X-direction and starts again upwards in the Y-direction. In this manner it travels over the surface 2 (Figure 1 1 ). Surface 2 may also be a horizontal surface e.g. a public square instead of a vertical wall of a house.

With the above described procedure a picture for example shown in Figure 1 1 can be produced. One colour (typically dark colour) is used for painting while the other colour (typically light colour) is presented by the basic colour of the wall. By placing the pixels sparsely on the lighter portions several hues of the colour used for painting can be produced. The opposite is also feasible, that is, when the basic colour of the wall is dark and the colour of the paint is light. Naturally, coloured picture can also be printed with this method by using the so called colour mixing known in the printing industry. In this method four colours (CMYK) are used and the coloured pixels positioned side by side give the impression of a mixed colour if viewed from far. Thus the colours are not really mixed only the peculiarities of the human eye are exploited as the dynamic range of the human eye is about one minute. On the basis of this the size of the pixels to be used can be calculated for the distance from where the picture is blended for the eye and can be enjoyed.

Supporting elements 5 of the previously described apparatuses 1 are moved by a solenoid secured to a stationary component. However, in another solution all of the supporting elements 5 are surrounded by a coil and the supporting element 5 itself presents the iron core (Figure 4). Thus the solenoid (electromagnet) itself belongs to the rotating part and as many of them are needed as many supporting elements 5 are used. This embodiment makes apparatus 1 a bit more expensive and heavier but in some special cases its use is reasonable.

Differently from the above solutions instead of using cylindrical rotational movement linear movement is used for painting. Mathematically it means a cylinder with an endless diameter. Supporting elements 5 may be arranged for example in a matrix (Figure 10). Apparatus 1 may be moved continuously at a constant speed. Then the supporting elements 5 are pushed out at the required point during travel. In another embodiment the operation may be divided in sections where the system does not move during painting but then the whole matrix is moved on by a matrix size where it is stopped, painting is performed by the respective supporting elements 5 then again moved on by a matrix size. In this case the paint is not loaded on supporting elements 5 by means of rollers 20, 23. Instead, a duct 18 is provided in supporting elements 5 through which the required amount of paint is carried to sponges 7. Feeding of the paint is known in the art.

The advantage of the apparatus of the present invention is that decorating vertical, horizontal, slanting, flat or even humped surfaces of different objects with various graphics becomes simpler and cheaper as compared to the known solutions. As opposed to the spray technique painting with sponge pixels is easier, cheaper and it needs less component parts and requires fewer repairs. A possible failure can be recognized and repaired easily. Correct positioning of the apparatus according to the invention can be performed by means of the X-Y coordinate system scaffolding and by using the known CNC technology, the elements for loading the paint can be controlled easily.

Claims

1 . Apparatus for decorating the surface of buildings, especially with graphics, advertisements wherein the decoration is represented by pixels, the pixels are applied on the surface by means of sponges provided with paint, the size of the outer surface of the sponges corresponds to the size of the pixel; the sponges are arranged in a housing having cylindrical or flat lateral faces and are operated by a driving mechanism fixed to a supporting element; during contact of the sponge and the surface the required paint is carried to the sponge through dipping or filling , the distance between the housing and the surface is set by a spacer while the position of the housing is set by a positioning means in a known manner; the driving mechanisms and the positioning means are controlled by a control unit running a program suitable for producing the decoration; and the apparatus is forced to move essentially parallel with the plane of the surface characterized in that said supporting elements (5) are provided with supporting arms (1 1 ) and supporting plates (13) placed essentially perpendicular to the outer end (12) of said supporting arms (1 1 ) for holding said sponges (7) in position; said supporting arms (1 1 ) of said supporting elements (5) are introduced to the interior of said housing (4) through the wall of said housing (4) and are guided perpendicular to the axis of rotation (16) of said housing (4) or to the lateral face of said housing (4) opposite the surface (2); said supporting elements (5) are arranged movably and flexibly between their internal state of rest and their outer active state and/or they can be switched between the two positions; said driving mechanism (6) is operated electromagnetically or pneumatically or hydraulically, said driving mechanism(s) (6) are provided with transmitting element(s) (14) in order to ensure axial movement of said supporting arm (1 1 ) of the supporting element(s) (5), said transmitting element(s) (14) are arranged in the same axial direction as said supporting arm(s) (1 1 ) of the respective supporting element(s) (5) at least at the time of the position change of said supporting arm(s) (1 1 ) between their active state and rest state and they communicate with the inner end (15) of said supporting arm(s) (1 1 ); for producing a pixel (3) at least the sponge (7) of the respective supporting element (5) operated by said transmitting element (14) is filled with paint, and by switching said supporting element (5) into its active state said sponge (7) is in communication with said surface (2) for the time of application of the paint.

2. Apparatus according to claim 1 characterized in that a duct (18) connected to said sponge (7) is formed in said supporting arms (1 1 ) of said supporting elements (5).

3. Apparatus according to claim 1 characterized in that a tank (19) or a paint roller (20) is connected to said apparatus (1 ).

4. Apparatus according to any of claims 1 - 3 characterized in that said driving mechanism (6) is a solenoid the coil of which is fixed within the housing (4) while its iron core is represented by said transmitting element (14) which ensures axial movement of said supporting arms (1 1 ) of said supporting elements (5), and said driving mechanisms (6) are arranged in said housing (4) in the direction of movement of said supporting elements (5) perpendicular to said surface(2).

5. Apparatus according to claim 4 characterized in that said transmitting element (14) is represented by said supporting element (5) itself surrounded by its solenoid coil.

6. Apparatus according to any of claims 1 - 5 characterized in that said housing (4) comprises segments of a cylinder (21 ) with a height of a pixel (3) engaged to each other uniaxially, at the centre of each segment of a cylinder (21 ) a driving mechanism (6) is arranged, the supporting elements (5) provided with sponge (7) are arranged radially around the driving mechanism (6) in the wall of housing (4), and the transmitting element(s) (14) and the supporting arm(s) (1 1 ) of the supporting element(s) (5) are arranged uniaxially at least at the time of their position change between the active or rest state; the speed of progression of apparatus (1 ) and the peripheral speed of sponges (7) of supporting elements (5) in their active state are chosen to be equal, the distance between said housing (4) and said surface (2) is greater than the distance between said supporting elements (5) being in the state of rest (not in contact position) and said surface (2) and smaller than the greatest axial distance said supporting elements (5) can be extended.

7. Apparatus according to any of claims 1 - 5 characterized in that said housing (4) has a cylindrical wall, the driving mechanisms (6) are arranged equidistantly from each other inside of said housing (4) so that the transmitting elements (14) are positioned in radial direction perpendicular to the axis of rotation (16) of said housing (4), the supporting elements (5) provided with sponge (7) are arranged radially around the driving mechanisms (6) in the wall of housing (4), and the transmitting element(s) (14) and the supporting arm(s) (1 1 ) of the supporting element(s) (5) are arranged uniaxially at least at the time of their position change between the active or rest state; the speed of progression of apparatus (1 ) and the peripheral speed of sponges (7) of supporting elements (5) in their active state are chosen to be equal, the distance between said housing (4) and said surface (2) is greater than the distance between said supporting elements (5) being in the state of rest and said surface (2) and smaller than the greatest axial distance said supporting elements (5) can be extended; and the supporting element(s) (5) painting the pixel (3) get in the active state before facing the surface (2).

8. Apparatus according to any of claims 1 - 8 characterized in that said housing (4) is prismatic, said supporting arms (1 1 ) of said supporting elements (5) are arranged in a matrix through the lateral face (17) of said housing (4) facing surface (2), the transmitting elements (14) of driving mechanism (6) are connected to supporting arms (1 1 ) of supporting elements (5) and said housing (4) is directed at a distance from surface (2) so that sponges (7) of supporting elements (5) being in active state reach surface (2) but the sponges (7) being in the state of rest are at a certain distance from surface (2).

9. Apparatus according to any of claims 1 - 8 characterized in that said apparatus (1 ) is mounted on a scaffolding (22) ensuring two- or three-dimensional movement of said apparatus (1 ) and the operation of said scaffolding (22) is CNC controlled.

10. Apparatus according to any of claims 1 - 9 characterized in that said spacer (8) is an idler.

1 1 . Apparatus according to any of claims 1 - 10- characterized in that the normal position of supporting elements (5) is the state of rest - preferably realized by using elastic support or spring force - and they are moved from their state of rest to their active state only when they are in paint position.

12. Apparatus according to any of claims 1 - 1 1 - characterized in that said positioning means (9) is a step motor (24).