DISPLAY DEVICE

Abstract: The invention relates to an electronic label having an information zone (19) movable from a first concealed position to a second revealed position by means of an actuating means (31).

Description: Display Devices Technical Field of the Invention The present invention relates to a movable display device of the type according to the preambles of the independent claims. The present invention further relates to an electronic label of the type according to claim 8. Description of Related Art In many shops price information for the goods on display is shown on labels located on the edges of the shelves supporting the goods. Recently automatic price information systems have become available. WO-A-86102477 discloses a price information system comprising electronic prices labels. These labels, which are mounted on shelves in shops, are in the form of individual price display units comprising a display screen, an internal power source, a memory with an individual address and a receiver for remote communication with a master control unit. This master control unit broadcasts price information which can be addressed to an individual price display unit which, after receiving the transmitted information, displays the price information on its display screen. The advantage of such systems is that the consuming and error- prone manual changing of labels is avoided. In order to reduce the power consumption of such electronic labels and thereby prolong the battery life the display screens in such labels are usually based on low- power liquid crystal display (LCD) technology. A typical power consumption for an electronic label using an liquid crystal display is in the order of 0.01 W. It is common practice in shops to draw customers' attention to products which have a lower than usual price, which have particularly desirable features (e.g. environmentally friendly, low-fat, low-cholesterol, etc) or which are the object of a special advertising campaign. A common way of doing this with normal paper labels is to manually provide the usually white price label with a field which can be filled with an adhesive label having a contrasting colour, for example bright red, or containing written information or a picture or symbol. It is also desirable to attract customers' attention when electronic displays are being used. Thus the above mentioned manual method of drawing attention to a product has also been used in combination with electronic labels of the type described above. This method is however both time-consuming and error-prone and therefore leads to a loss of some of the advantages of electronic labels. In order to avoid the problems associated with manually providing attention attracting zones on electronic labels various electronic attention attracting means have been proposed. A simple method of attracting attention was obtained by providing an electronic label with a suitably coloured light emitting diode (LED) which could be made to flash at regular intervals when the associated product was on special offer. This method is unsatisfactory for use with battery powered electronic labels as the average power consumption of a flashing LED is in the order of 1 mW and this reduces the battery life by a factor of 100. Furthermore tests have shown that consumers find the displays unattractive. In an attempt to overcome the above problems the LCD price display screen can be made to flash on and off. Such a label is known from WO-A 96132683. Alternatively the LCD segment can be coloured and flashed on and off or it can placed in front of a coloured background which can be alternately masked and revealed by changing the transparency of the LCD display. This method has a low battery consumption. Tests have however shown that such displays are not easily visible, particularly from the side i.e. they have a low viewing angle, and hence are not satisfactory. Summary The present invention seeks to solve the problems with prior art labels by providing an electronic label with the features taught in the characterising parts of the independent claims. With the label according to the invention an actuating means is provided which provides an effective way of drawing attention to a label by changing the appearance of the label while at the same time the energy consumption of the label is kept to a minimum. Further features of the present invention are mentioned in the dependent claims. In an embodiment of the present invention the actuating means comprises an electromagnetic device which co-operates with a movable, preferably coloured, attention attracting or information carrying zone (called information zone from now on for the sake of brevity) which is provided on a pivotally mounted magnet means. The magnet means can be made to pivot by the application of a magnetic field so as to move the information zone from a first position where the information zone is hidden to a second position where the information zone is visible. The magnet field is produced by the electro-magnetic device which preferably can retain a residual magnetic field after being activated so that the information zone is retained in the desired position without the magnetic field producing means requiring a constant supply of energy. Alternatively such stable desired positions can be obtained by using, for example, gravity, friction or mechanical means such as latching means or stops. In another embodiment of the invention the information zone is provided on laterally displaceable magnet means. The magnet means can be displaced by the application of a magnetic field so as to move the information zone from a first position where the information zone is hidden to a second position where the information zone is visible. Yet another embodiment of the invention provides for more than two stable positions. A further embodiment of the invention provides for multiple zones. Brief Description of the Drawings Figure la) is a simplified enlarged plane view of an embodiment of an electronic label with a rotatable zone according to the invention; Figure lb) is lateral view of the electronic label shown in figure la); Figure 2a) is a simplified enlarged plane view of a second embodiment of an electronic label with a rotatable zone according to the invention; Figure 2b) is lateral view of the electronic label shown in figure 2a); Figure 3 a) shows schematically in perspective an embodiment of an electronic label with a linearly displaceable zone according to the invention; Figure 3b) shows a cross-section along line III-III in figure 3a) with an information zone in a hidden position, Figure 3 c) shows a cross-section along line III-III in figure 3 a) with an information zone in a displayed position, Figure 4 shows in perspective an actuating means for a further embodiment of the invention. Figure 5 shows a perspective exploded view of a further embodiment of a rotatable information zone according to the invention. Figure 6 shows a perspective exploded view of yet another embodiment of a rotatable information zone according to the invention. Figure 7 shows a perspective view of a rotatable shutter according to the invention. Detailed Description of Embodiments Figures la) and lb) show an embodiment of an electronic label 1 according to the invention in which, for the sake of clarity of illustration, constructional details which are not relevant for the present invention have been omitted. Label 1 has a box-like casing 3 which has a front face 5. Face 5 supports a display screen 7, a field 9 and a transparent or semi-transparent window 1 1. Display screen 7 is preferably a LCD screen which can display alphamimerical characters and/or symbols. Field 9 could be, for example, a solar panel for supplying the label with energy, a display for displaying product information or a holder for accepting a product information card. Behind window 11 is an attention-attracting means 13. In this embodiment it comprises a substantially cylindrical body 15 rotatably mounted by projecting axial pins 17 in corresponding recesses (not shown) in the casing 3. The cylindrical surface of body 15 is divided into approximately two semi-cylindrical mformation zones 19, 21 which in this embodiment are not identical in size. Zone 19, which here subtends an angle of approximately 135 °, is coloured an attention-attracting colour such as, for example fluorescent red, yellow or green or a colour contrasting with the colour of casing 3. Zone 19 can also be provided with advertising text, e.g. "special offer" or "low price", or symbols such as product trade marks. It is possible to have zones of equal size, i.e. with zone 19 subtending an angle of 180 °, or zone 19 can be bigger than zone 21. Zone 21 has preferably a neutral colour which may be, for example, the same as that of casing 3, or white or grey. Zone 21 could also be provided with a attention- attracting colour or text which is different to that provided on zone 19. Body 15 contains a magnetic body 23 which has its north pole to south pole axis aligned with the radial of the cylinder which is approximately perpendicular to the longitudinal line of symmetry which bisects zones 19, 21. Magnetic body 23 is firmly attached to body 15 so that if magnetic body 23 rotates around the longitudinal axis of body 15 due to the influence of a magnetic field then body 15 moves correspondingly. Casing 3 contains label control means 25, energy storing means 27 and communicating means 29 of any suitable type for receiving signals from, and preferably also transmitting signals to, a central price control device and/or handheld price control devices. Casing 3 also contains an actuating means in the form of an electromagnet 31 connected to control means 25. Electromagnet 31 comprises a coil 33 which surrounds a core 35. Core 35 is preferably made of a material which retains a magnetic field even when the exciting current has been removed, an example of such a material is a semi-permeable material. Core 35 is positioned with one pole 37 sufficiently close to body 15 that magnetic body 23 can be influenced by the magnetic field of electromagnet 31. In the figure core 35 is show positioned vertically but it may also be positioned at any other angle, e.g. horizontally or inclined to the horizontal. Control means 25 can control the supply of electricity to coil 33 of electromagnet 31 so that core 35 can be selectively magnetised with pole 37 as the north pole or pole 39 as the north pole. Control means connects coil 33 to the electricity supply for a period of time sufficient to induce the desired magnetic field in core 35. If the material of the core is made of a substance which retains a magnetic field, e.g. a semi-permeable material, then it can retain its magnetic field and cylinder 15 stays in its desired position without any further energy consumption. If core 35 cannot retain a magnetic field then cylinder 15 can be provided with some latching means (not shown) which retain it in the desired orientation. Alternatively gravity or friction can be used to maintain the cylinder 15 in a desired position. When pole 37 is made into a north pole then the south pole S of magnetic body 23 is attracted to pole 37 and the cylindrical body rotates so that south pole S of magnetic body 23 is as close as possible to pole 37. In the case shown in the figure this would mean that the information zone 19 would be visible through window 11. When pole 39 is made into a north pole then the north pole N of magnetic body 23 is attracted to pole 37 which is now a south pole and cylindrical body 15 rotates so that north pole N of magnetic body 23 is as close as possible to pole 37. This causes the neutral zone 21 of cylindrical body 15 to be visible through window 11. Label 1 can be optionally provided with any suitable type of magnetic or electrical or mechanical sensing means 40 which can sense the orientation of cylindrical body 15. Such means could be, for example, proximity sensors, micro switches, strain gauges, optical sensors and the like. Sensing means 40 can be connected to control means 20 which can activate an alarm device (not shown) on label 1 and/or cause communication means 29 to send out an alarm signal if an incorrect orientation is sensed. When it is desired to attract attention to a price label according to the invention it is possible by means of control means 25 and electromagnet 31 to select an attention actuating background to window 11. This is performed by sending a signal to control means 25 which consequently connects the electromagnet coil 33 to the power supply in an appropriate manner for causing the magnetic poles of the core to swap ends. The coil 33 is connected to the power supply for a predetermined length of time. This length of time is sufficient to cause the pole of the core 35 to swap ends and, in the case the core 35 is made of a semi-permeable material, for the core 35 to retain a residual magnetic field. This change in magnetic field causes the magnetic body 23 and body 15 to rotate one half of a revolution around the longitudinal axis of body 15 and the information zone to become visible through window 11. In order to return to a neutral background control means 25 connects the coil 33 to the power supply with the opposite polarity so that the magnetic poles of the core 35 swap ends and the body 15 rotates through a half revolution. This brings the neutral coloured background zone 21 to a position behind the window 11. As no extra energy is required to retain the body 15 in its intended position the attention attracting means according to the invention provides an attention attracting means with a low consumption of energy. While the embodiment shown in figures la) and lb) has an essentially planar front surface it is possible to provide it with a transparent convex semi-cylindrical window which projects out from the front surface. This could permit a larger cylindrical body to be used and if part of the body project out beyond the plane of the front surface it would permit a greater viewing angle. A label 1 can furthermore be provided with a plurality of cylindrical bodies and actuating means. Figures 2a) and 2b) show an embodiment of the invention similar to that shown in figures la) and lb) in which the cylindrical body 15 has three information zones 19', 19", 19'" and a neutral zone 21 '. These zones are shown here to be of equal size and symmetrically positioned around the circumference of cylinder 15 but they may be of different sizes and asymmetrically positioned. As mentioned in connection with the previous embodiment the zones 19', 19", 19'", 21' can each be coloured an attention-attracting colour such as, for example fluorescent red, yellow or green or a colour contrasting with the colour of casing 3 or a neutral colour or they can be provided with advertising text, e.g. "special offer" or "low price", or symbols such as product trade marks. Body 15 contains two mutually spaced magnetic bodies 23', 23", and casing 3 contains 2 mutually spaced actuating means in the form of electromagnets 31', 31". Magnetic bodies 23 ', 23 " and actuating means 31 ', 31 " are so positioned that it is possible to rotate cylinder 15 so that each of the zones 19', 19", 19", 21' can be selectively positioned so as to be visible through window 11. Thus, for example magnetic bodies 23', 23" could be mounted on cylinder 15 mutually perpendicular and aligned with the lines of symmetry of the zones 19', 19", 19'", 21 ' while actuating means 31', 31" could be mounted on casing 3' mutually perpendicular and with actuating means 31" aligned with the axis of symmetry of window 11 ' . In figures 2a) and 2b) zone 19' is shown positioned behind window 11 '. Window 11' is shown protruding from the front face 5 ' of casing 3 ' in order to provide a wider field of view. Zone 19" can be moved to the position behind window 11' by appropriate actuation of actuating means 31" which then has sufficient magnetic force to overcome the residual magnetic field of actuating means 31 '. It is also optionally possible to assist the rotation of cylindrical body 15' by changing the polarity of actuating means 31' a short period of time before the actuation of actuating means 31" in order to start cylindrical body 15' rotating. While this embodiment has only 4 zones it is of course possible to adapt it to have a greater number of zones by providing more magnets and actuating means. In a further embodiment of the invention (not shown) the cylindrical body 15 can be divided into a plurality of concentric longimdtnal sections 15a, 15b, 15c each able to rotate independently around a common longitudinal axis. Each section can be provided with a plurality of display zones and a corresponding number of magnetic bodies. While the sections can have similar diameters and lengths, it is also conceivable that they have different diameters and/or lengths. Figures 3 a) shows schematically in perspective a label comprising an embodiment of a linearly displaceable attention-attracting means according to the invention. In this figure only the components relating to the information zone are shown for the sake of clarity of illustration. In the front face 5 of casing 3" is a window 11" behind which is a number of slots 41 separated by a strip or strips 43 of, preferably, front casing material. Two slots 41 are shown here but any number of slots may conceivably be used. The information zone 19"" is mounted on or is an integral part of a surface of a flexible film made of, for example, plastic and/or paper and/or metal foil 45', 45" which can be substantially linearly displaced from a position behind bars 43 (as shown in figure 3b)) via slots 41 to a position in front of bars 43 and casing front face 5 (as shown in figure 3c)). In the embodiment shown the information zone 19"" is formed by two pieces of film 45', 45" attached to a flexible carrier 47 which is connected to a cylindrical body 15'". Cylindrical body 15"' can rotate about its longitudinal axis and contains a magnet 49. Magnet 49 has a north pole 51 and a south pole 53 which can be influenced by an electromagnet 51. By applying an appropriate current to electromagnet 51 cylindrical body 15'" can be made to rotate 180° about its longitudinal axis from the position shown in figure 3b to the position shown in figure 3c). In figure 3b) it can be seen that a ramp 53', 53" of, preferably for the sake of ease of manufacturing, front casing material continues down from the front surface below each of slots 41. Film 45' is hidden behind strip 43 while film 45" is hidden behind the casing front face 5. Part of carrier 47 is half wound around cylindrical body 15'". In this position films 45', 45", and consequently information zones 19"", are not visible through slots 41. Cylinder 15'" is preferably provided with rotation limiting means, for example a projection (not shown) which can co-operate with a suitably positioned stop (not shown) which prevents it winding more of carrier 47 around it. When it is desired to reveal information zone 19"" electromagnet 51 is actuated to reverse its polarity and thereby cause cylindrical body 10'" to rotate approximately 180°. This causes carrier 47 to move longitudinally and films 45', 45" to be displaced up ramps 53', 53". The dimensions of films 45', 45" and the diameter of cylindrical body 15'" and the distance between the slots is preferably chosen such that the part of the front surface between the slots is covered by film 45" in order to give a visually continuous information zone 19"". It is also possible to use a linear electromagnetic actuator, e.g. a solenoid, instead of a rotating body to provide the necessary linear displacement of the films 45', 45". Figure 4 shows schematically a further embodiment of a movable attention attracting or information carrying means intended to be mounted behind an opening, or window on a label. Two spaced apart, essentially parallel cylindrical bodies 59', 59", support an endless belt 61 of flexible material 63. The flexible material 63 has an outer surface 65 which is divided into a number of zones 67', 67', 67"', etc. which can have different colours, symbols and/or information. Material 63 is in frictional or mechanical engagement with cylinders 59, 59' so that rotation of the cylinders cause a corresponding rotation of the flexible material 63. One or both of the cylinders 59', 59" are provided with driving means, for example of the electro-mechanical type described above, (not shown) for causing it or them to rotate. This rotation is used to move the different zones 67', 67", 67'" to a position visible through the opening or window. Figure 5 shows an embodiment of the invention in which a disk 69 of resilient, flexible material is radially slit in order to form 4 quadrants 7 -71" ". These quadrants 71'-71"" have upper surfaces which form information zones 73 '-73'"'. Disk 69 is rotatably mounted with the plane of the disk parallel and just below the plane of the front surface 75 of the label. Surface 75 has a X-shaped slot 77 formed in it. Each arm 79'-79"" of the slot is provided with a ramp 81 '-81'"' projecting down from one edge of the arm and extending to below the plane of disk 69. Disk 69 is provided with rotating actuating means 83 comprising for example a magnet 85 immovably attached to disk 69 and electromagnets 87', 87" immovably attached to the label (not shown). Suitable actuation of the electromagnets 87', 87" causes disk 69 to rotate and quadrants 71'-71"" to travel up ramps 81 '-81"" so that information zones 73 '-73'"' are displaced to a position in front of front surface 75. To suitable positioning of electromagnets 87', 87" it is possible to rotate disk 69 through any desirable angle, e.g. 110°, in which case the whole of the information zones 73'-73"" are in front of the front surface 75 when they are exposed yet they are completely hidden by the front surface 75 and ramps 79'-79" " when it is desired to have them hidden. Figure 6 shows a further embodiment of the invention in which a substantially flat disk 89 is rotatably mounted with the plane of the disk parallel and just below the plane of the front surface 91 of the label. The surface of disk 89 facing towards the front surface 91 of the label is divided in two 4 quadrants 93 '-93'". A first pair of diametrically opposed quadrants, 93', 93'" are used as information zones and are coloured or otherwise decorated appropriately, while the second pair of quadrants 93 " , 93 " " can be used as a neutral background or can contain other information. Front surface 91 has cut-outs 95', 95" positioned directly above disk 89 in such a way that only one pair of stationary quadrants 93 '-93'"' are visible at a time. Two quadrant shaped cut-outs 95 ',95" are shown here but they can be any shape, e.g. circles, squares, stars, triangles etc. or number. Disk 89 is rotatable by means of actuating means 97 comprising for example a magnet 99 immovably attached to disk 89 and electromagnets 101', 101" immovably attached to the label (not shown). Suitable actuation of the electromagnets 101', 101 " causes disk 89 to rotate through an angle of 90 ° and in this way alternative pairs of quadrants 93 '-93'"' can be positioned under cut-outs 95', 95". While this embodiment has been illustrated with 4 quadrants it is also conceivable to divide the surface of the disk into any number of information zones (e.g. just two zones) and then provide an appropriate number of cut-outs (e.g. one cut-out) and actuating means (e.g. one electromagnet). Further embodiments of electromagnetically or electromechanically actuated attention attracting devices are conceivable, for example the information zone could be immovable and be selectively concealable behind a movable shutter or cover. Such a device is shown in figure 7. The front surface 103 of a label is provided with an information zone shown here as a coloured star-shape 105. A movable shutter 107 with a neutral coloured top surface 109 is attracted to actuating means 110 comprising a crank-arm 111 attached by one end to the rotatable shaft 113 of shutter 107 and attached at the other end to a solenoid rod 115. Solenoid 117 can be connected to a power supply in order to linearly displace rod 115 between two different positions. In the first position shown in figure 7 the shutter 107 does not cover information zone 105. If a suitable power supply (not shown) is connected to solenoid 117 then rod 115 can be displaced to the left and shutter 107 will swing to the second position in which it covers information zone 105. If necessary latching means (not shown) can be provided, or friction used, to retain shutter 107 in the first and second positions. While the invention has been illustrated with examples of movable attention attracting means it is also conceivable that the movable zone could contain other information which it is desired to be able to selectively conceal or reveal. Such information could, for example, be a first zone with stacking information which it is only necessary to show to staff during re-supplying operations and a second zone with product information to the consumer. While re-supplying is taking place the staff member could cause the label to show the first zone, the second zone being displayed the rest of the time. It is furthermore possible that the electromechanical actuator is mounted on the movable body and the magnet immovably fixed onto the label. It is also conceivable to provide a label with a plurality of attention-attracting devices and to combine the features of the above described embodiments. While the invention has been illustrated with examples of embodiments using electro-magnets it is also possible to use stepper motors, miniature electric motors (possibly combined with a feedback or position sensing system) or indexing means to ensure the correct positioning of the display zones.

Claims: Claims 1. Movable display device for an electronic label characterised in that it comprises an information zone (19; 19'-19"';45\ 45"; 67'- 67"';71 '-71 ""; 93 ', 93'") movable from a first concealed position to a second revealed position by means of an actuating means (13; 31', 31"; 51; 83; 97). 2. Movable display device for an electronic label characterised in that it comprises an information zone (105) coverable by means of a shutter (107) movable from a first position to a second position by means of an actuating means (117). 3. Movable display according to claim 1 or claim 2 characterised in that said actuating means (13; 31', 31"; 51; 83; 97; 117) comprises an electromechanical actuating means such as an electromagnet (13; 31', 31"; 51; 83; 97), solenoid (117) or motor. 4. Movable display according to any of the previous claims characterised in that said actuating means comprises a magnetisable material (37). 5. Movable display according to claim 4 characterised in that said magnetisable material (37) retains a magnetic field after a magnetic field inducing force has been removed. 6. Movable display according to any of the previous claims characterised in that said information zone (19; 19'-19'";45', 45"; 67'- 67'";7r-71 ""; 93 ', 93'") is on or is connected to a movable body (15, 59', 59"; 61; 69; 89) comprising a magnetic body (23; 85; 99). 7. Movable display according to any of the previous claims characterised in that said information zone (19; 19'-19'";45', 45"; 67'- 67"';71 '-71 ""; 93 ', 93'") or shutter (107) is releasably retainable in said first and/or said second position. 8. Label comprising a movable display according to any of the previous claims.

Inventors: AHLSE MARC, AHLSE, MARC
Applicants: AHLSE MARC, PRICER AB, AHLSE, MARC
Application year: 1998
Main classification: G09F11
IPC codes: G09F9, G09F11