WO2002033680A2

WO2002033680A2 - A poster display device

Info

Publication number: WO2002033680A2
Application number: PCT/GB2001/004661
Authority: WO
Inventors: Philip Ketteringham; James Powell
Original assignee: Lestow Limited
Priority date: 2000-10-20
Filing date: 2001-10-19
Publication date: 2002-04-25
Also published as: GB2368181A; AU2001294072A1; WO2002033680A3; GB0025805D0

Abstract

A poster display device has a housing (2) having a display window (3) for displaying a poster. The housing contains: a poster store (9) for storing a plurality of posters (P); a poster selector (9, 101) for selecting any one of the posters from the poster store; and a poster displayer (101) for moving a selected poster to a display position at which the poster is visible through the display window (3). A control (200) apparatus may be provided to receive poster display control data from a remote location. The poster store (9) may be a rotatable carousel having poster storage locations spaced apart around its periphery for enabling a plurality of posters to be stored spaced apart around the carousel periphery each rolled up about a poster axis with the poster axes being parallel to the carousel rotation axis.

Description

A POSTER DISPLAY DEVICE

This invention relates to a poster display device for displaying advertising posters and the like.

Conventionally, advertising posters are displayed outdoors by sticking them to advertising hoardings and the like. This conventional arrangement has disadvantages in that the posters are exposed to damage by adverse weather conditions, vandalism and the like. Moreover, a poster may only be replaced by manually pasting another poster onto the advertising hoarding either on top of or after removing the previous poster.

Automatic poster display devices have been proposed wherein a number of different posters can be displayed in sequence. Examples of such poster display devices are disclosed in US Patent Nos. 4,205,801 and 4,162,585. In these devices, the posters are mounted on an endless band provided within a housing and the endless band is rotated by driving means so as to bring one poster after another into registration with a window of the housing. Although such automated display devices protect the posters from the elements and enable a number of different posters to be displayed automatically, the sequence of display of the posters is determined by the order in which the posters are secured to the endless bands and cannot be changed. In other known automated poster display devices, a number of three-faced elongate display elements are mounted parallel to one another so as to be rotatable about their elongate axis. In this automated display device, each face of each display element carries a segment of a different poster and rotation of the display elements in synchronism enables three different posters to be displayed one after another. Again, the sequence of display of the posters is determined by the order in which the poster segments are mounted to the display elements. Furthermore, this automated poster display device is relatively complex in that it requires posters to be segmented for display and, moreover, requires that the different display elements rotate in synchronism so as to ensure that the posters are correctly displayed.

It is an aim of the present invention to provide a poster display device that enables any one of a number of posters to be displayed in any desired order.

It is an aim of the present invention to provide a poster display device which enables control over the poster being displayed to be effected by data provided from a location remote from the poster display device.

In one aspect, the present invention provides a poster display device comprising a poster selecting means for selecting any one of a number of posters for display. This enables the posters to be displayed in any desired order. In another aspect, the present invention provides a poster display device having communication means for communicating with control apparatus located away from the poster display device to receive poster display control data from the communication means and control means for controlling the display of posters in accordance with the poster display control data. This enables control over the poster being displayed by a person who does not have to be physically present at the poster.

In another aspect, the present invention provides a poster display device adapted to communicate with control apparatus using the GSM network to enable remote control of poster display and/or communication of status information.

In another aspect, the present invention provides a control apparatus for communicating with a poster display device via a network system to enable control of the poster display device by the control apparatus. The control apparatus may be adapted to communicate with the poster display device via a network such as the GSM network, a landline telephone communication network or a computer network such as a local area or wide area networ .

In another aspect, the present invention provides a poster assembly for use in a poster display device wherein the poster assembly comprises a former onto which a poster is rollable, a support for supporting a free-end of the poster and biasing means for biasing the poster into a condition in which the poster is rolled up on the former.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a diagrammatic front view of a poster display device in accordance with the present invention located in a position of use;

Figure 2 shows a diagram to illustrate communication between a control apparatus and the poster display device shown in Figure 1;

Figures 3 and 4 are functional block diagrams of a base station and a host computer, respectively, shown in Figure 2;

Figure 5 shows a simplified front view of the poster display device shown in Figure 1 with a front portion of a housing removed to show the main mechanical components;

Figure 6 shows a simplified side-view, with a side portion of the housing removed, of mechanical components of the poster display device; Figure 7 shows a functional block diagram of a control system of the poster display device shown in Figure 1;

Figure 8a shows in detail one end plate of a poster carousel of the poster display device shown in Figure 1 while Figure 8b shows a perspective view of part of the carousel to illustrate how a poster is held by the carousel;

Figure 9a shows a part sectional fragmented view of one example of a poster assembly for use in the display device shown in Figure 1 while Figures 9b and 9c show cross-sectional views taken on the lines A-A and B-B, respectively, in Figure 9a, Figure 9d shows a poster stick support of the poster assembly, and Figure 9e shows a front view of a poster assembly with the poster in an unrolled configuration and with the poster stick supports removed;

Figures 10 and 11 show, respectively, schematic perspective views of upper and lower parts of mechanical components of the poster display device to illustrate in detail carousel and lifter drive arrangements;

Figures 12 to 15 are flow charts illustrating functioning of the control system shown in Figure 7 during operation of the poster display device;

Figures 16 to 18 are schematic perspective views of part of the carousel and a lifter assembly to illustrate selection of a prime poster assembly while Figures 19 and 20 are schematic respective views of part of the lifter assembly and a prime poster support arrangement for illustrating securement of a prime poster in an unrolled display configuration;

Figures 21a to 21c, 22 and 23 are schematic perspective views of parts of the carousel and the lifter assembly to illustrate selection of a secondary poster assembly;

Figure 24 shows a schematic perspective view of part of the prime poster support arrangement and lifter assembly with the poster stick of the prime poster assembly secured to the prime poster support arrangement and a secondary poster assembly carried by the lifter assembly to illustrate unrolling of the primary poster while the secondary poster is being rolled up;

Figure 25 shows a schematic side-view of the housing of the poster display device to illustrate opening of the housing to enable access to the internal components;

Figure 26 shows a flow chart illustrating steps carried out a host computer of the control apparatus shown in Figure 2 in a method for transmitting poster display control data to a poster display device;

Figures 27a to 27d show screens that may be displayed to an authorised user during steps of the method shown in Figure 26; Figures 28a to 28d illustrate databases stored in a database store of the host computer;

Figure 29 shows a flow chart illustrating steps carried out by a base station to transmit poster display control data to a poster display device;

Figures 30 and 31 show very diagrammatic perspective views for illustrating various modifications of the poster display device; and

Figure 32 shows a very diagrammatic side plan view of part of another example of a poster display device embodying the invention with a side portion of the housing removed.

Referring now to the drawings, Figure 1 shows an embodiment of a poster display device 1 in accordance with the present invention installed on a wall W of a building, for example, a side wall of a house, factory or the like.

The poster display device 1 has a housing 2 which, in this example, is formed of either metal or a toughened plastics material with a light transmissive toughened plastics material window 3 which is typically formed of polycarbonate. As shown, the housing 2 and window 3 are generally rectangular (possibly with rounded corners) when viewed from the front and have an aspect ratio of 3:2 (height:width) . In this example, the housing 2 and window 3 are dimensioned so as to enable the window to display a poster which is 3 metres high by 2 metres wide.

The housing 2 is mounted to the wall using conventional mounting brackets (bracket not shown) . A pedestal 4 is provided beneath the housing 2 to provide a waterproof and tamper proof passage for enabling connection of electrical components of the poster display device 1 to the mains AC power supply. Generally the pedestal 4 will be concreted into the ground at the base of the wall .

As will be explained in greater detail below and as shown very diagrammatically in Figure 2, the poster display device 1 is arranged to communicate with a remote control apparatus 5 to enable operation of the poster display device 1 to be controlled remotely.

In this example, the control apparatus 5 comprises a base station 6 and a host computer 7. The base station 6 and poster display device 1 each have a GSM transceiver (illustrated schematically in Figure 2 by antennas Al and A2 ) for enabling communication between base station 6 and the poster display device 1 over the GSM network in accordance with the standard GSM protocols. Figure 3 shows a block diagram illustrating the main components of the base station 6. The base station 6 is, in this example, a personal computer comprising a central processing unit (CPU) 60 with associated memory (ROM and/or RAM) 61, a hard disk drive (HD) 62, a display 63, a user input device 64 in the form of a keyboard and/or mouse, a removable disk drive (RDD) 65 for receiving a removable disk RD, a GSM interface 66 for enabling communication with a poster display device 1 over the GSM network and a communications interface 67 for communications with the host computer 7.

Figure 4 shows a block diagram of the host computer 7. In this example, the host computer 7 is a work station having a central processing unit 70 with associated memory (ROM and/or RAM) 71, a hard disk drive 72, a display 73, a user input device (keyboard and/or pointing device such as a mouse) 74, a removable disk disk drive 75 for receiving a movable disk RD, a remote communications interface 76 and a communications interface 77 for enabling communication with the base station. In this example, the communication between the base station 6 and the host computer 7 is via a UTP category 5 Ethernet connection. However any suitable communication arrangement may be used.

The removable disk disk drives 65 and 75 may be floppy disk, CD ROM, DVD disk drives or any combination of these. The remote communications interface 76 may be, for example, a MODEM enabling connection to the Internet and/or a network interface enabling the host computer 7 to be coupled in a local area or wide area network (LAN or WAN) .

The personal computer forming the base station 6 is, in this example configured to use the Windows NT4 operating system while the work station forming the host computer 7 is configured to use the UNIX operating system.

Program instructions and/or data for configuring operation of the base station 6 may be downloaded from a removable disk RD inserted into the removable disk disk drive 65 or as a signal S via the communication interface 77 connecting it to the host computer 7. The host computer 7 may similarly be configured by downloading program instructions and/or data from a removable disk RD received in the removable disk disk drive 75, or from a signal S supplied via the remote communications interface 76.

The functional components of the poster display device 1 will now be described with reference to Figures 5, 6, 7 and 8a.

Figure 5 shows a front view (with a front portion of the housing 2 omitted) and Figure 6 shows a side view (with a side portion of the housing 2 and the majority of the internal components omitted) of the poster display device 1 to illustrate the main mechanical components of the device while Figure 7 shows a functional block diagram for illustrating the main electrical components of the poster display device. Figure 8a shows a perspective view of a carousel poster support plate.

The main mechanical components of the poster display device 1 as shown in Figure 6 are: a poster carousel 9 for carrying a number, in this example 11 or 12, of posters to be displayed; a poster lifter assembly 10 for raising a poster from the poster carousel to a display position as will be described in detail below; and a prime poster support arrangement 11 for securing a prime poster in position as will be described in detail below.

As shown in Figure 5, the poster carousel 9 comprises a carousel axle 91 on which two poster support plates 92 of generally circular configuration are held in place by securement bosses 92a so as to be spaced-apart along the axle 91. Each poster support plate 92 has a series of slots 93 (see Figure 6) spaced apart around its periphery so that a poster assembly 12 can, as shown in Figure 5, be supported between opposed slots 93 of the two poster support plates 91 with ends of a poster axle 121 being received in respective ones of the two opposed slots 93. As shown most clearly in Figures 8a and 8b, each slot 93 has a closure latch 94 which is pivotally mounted to the support plate 92 and secured in place by a pivot pin 94a having a bolt head 94 ' a which stands proud of the support plate 91. Each closure latch 94 is spring biased by a spring which is not shown into a position closing the slot 93 to retain a poster axle end within the slot 93.

Respective ends 91a of the carousel axle are journalled in bearings provided in upright members 8a of a chassis frame 8 secured to the interior of the housing. One of the carousel axle ends 91' a is coupled to a carousel drive motor 99. In this embodiment, the carousel drive motor 99 is a stepper motor and a proximity sensor 95 is provided to sense the position of the slots 93 by sensing the location of the bolt heads 94' a of the pivot pins 94a securing the closure latches 94 to one of the support plates 91.

The motor 99 operates under the control of control circuitry 200 which will be described below. In the interests of simplicity connections to the control circuitry 200 are not shown in Figure 5.

The poster lifter assembly 10 comprises a lifter bar 101 each end of which is secured to a respective endless belt 102. Each endless belt 102 extends around upper and lower pulleys 103 and 104.

The lower pulleys 104 are rotatably journalled in respective ones of the chassis upright members 8a while the upper pulleys 103 are mounted on a lifter pulley axle 110 (see Figure 6) which is coupled via a drive mechanism to a lifter drive motor 105 (Figure 5). In the interest of simplicity, the drive coupling is not shown in detail in Figure 5 and not shown at all in Figure 6. As will be appreciated by the person skilled in the art, this drive coupling may be a directly geared coupling between the drive shaft and the carousel axle or may be a belt drive arrangement.

Upper and lower proximity sensors 106 and 107 are mounted adjacent to windows 8'a in one of the chassis upright members 8a to detect when the lifter bar 101 reaches predetermined upper and lower positions, respectively along the endless belts 102. The sensors 106 and 107 enable the control circuitry 200 to calibrate movement of the lifter bar 101 along the endless belts 102 so that operation of the lifter drive motor 105 can be controlled by the control circuitry 200 to enable the lifter bar 101 to be lowered to allow jaws 109 of the lifter bar 101 to engage part of a poster assembly and to be raised to enable, as will be explained in greater detail below, securement of a prime poster to the prime poster support 11 and unrolling and rolling up of a prime and a secondary poster.

To facilitate viewing of a displayed poster, a back lighting arrangement is supported on a rear surface of the interior of the housing. As shown schematically in Figure 5, the back lighting arrangement consists of a plurality of spaced-apart fluorescent tubes 13. Operation of the back lighting arrangement is controlled by the control circuitry 200 and an ambient light sensor 131 may be provided on the exterior of the housing as shown in Figures 1 and 5 to enable the degree of back lighting to be controlled in accordance with ambient light levels.

A poster recognition device 14 is also mounted within the housing to enable individual posters to be recognised. In this case, the poster recognition device 14 comprises a bar code reader for reading bar codes provided on the leading edges of the posters.

An access panel 2b in the bottom of the housing 2 enables wiring to enter the housing from the pedestal 4.

Figure 7 shows a block diagram of the electrical circuitry of the poster display device 1.

The control circuitry 200 comprises a processor or microcontroller 201 which is coupled to a power supply arrangement 202 which, in this example, comprises a conventional power supply unit 202a for deriving, via a mains interface 202b the necessary power supplies for all of the electrical components of the poster display device 1 from a mains AC supply. In the interests of simplicity, Figure 7 does not show all of the power supply connections from the power supply unit 202a to each of the individual electrical components. The power supply arrangement 202 is provided with a battery backup 202c to enable the poster display device 1 to continue operating for a predetermined period of time in the event of a mains power supply failure. As another possibility an uninterruptable power supply (UPS) of known type may be used. The mains interface 202b is coupled to the street mains AC power supply via the access panel 2b (Figure 5) and communications channel provided through the pedestal 4 shown in Figure 1.

The processor or microcontroller 201 is coupled to the upper and lower sensors 106 and 107, the proximity sensor 95, the poster recognition device 14, a safety interlock 15 coupled to the access panel 2a and a prime poster latch solenoid llf. The control circuitry 200 includes a lifter driver circuit 105a and a carousel driver circuit 99a for enabling the processor 201 to control operation of the lifter and carousel motors 105 and 99 respectively. The processor 201 is also coupled to a conventional light management unit (LMU) 132 which is coupled, in known manner to the fluorescent tubes 13 via respective ballasts 133. As mentioned above, an ambient light sensor (SE in Figure 7) 131 may be coupled to the processor 201 to enable the processor 201 to control operation of the light management unit 132 in accordance with ambient light levels. The processor 201 is also coupled to the GSM interface 66 to enable communications with the base station and to an indicator panel 16 to enable status indication to be provided to an operative during loading and unloading of posters.

The processor 201 is also associated with a memory 201a which will generally be in the form of battery backed-up RAM for storing poster identity data and poster display control data determining the time at which and the length of the time for which individual posters are to be displayed. This information is supplied to the control circuitry 200 over the GSM communication link with the base station 6.

The construction of the carousel 9 and a poster assembly 12 will now be described in greater detail with reference to Figures 8 and 9 in which Figure 8a shows a view of an outermost surface of a carousel poster support plate 92 while Figure 8b shows a perspective view of part of a carousel poster support plate 92 showing a poster assembly 12 supported by the poster support plate 92 and Figures 9a to 9e are views showing various aspects of a poster assembly 12.

As shown in Figure 8a, each poster support plate 92 has 11 peripheral slots 93 each arranged to receive an end of a poster axle 121 although there may be more (for example 12) or less slots. As can be seen most clearly in Figure 8b, each slot 93 has an outwardly flaring opening 93a to facilitate guiding of a poster axle 121 into and out of slot 93.

Each slot 93 is associated with a closure latch 94. Each closure latch 94 is pivotally mounted on the support plate 92 by the corresponding pivot pin 94a and is biased by a biasing spring (not shown) into the closed condition in Figure 8a so that, when a poster axle 121 end is received in a slot 93, the closure latch 94 retains the axle 121 within the slot. Each closure latch 94 has a nose shaped radially outermost portion 94b which causes a poster axle 121 end to rotate the closure latch 94 against the spring biasing force as the poster axle 121 end is pushed into the slot 94 by a person loading the carousel 9.

Each closure latch 94 also has an abutment surface 94c carried by the nose portion 94b and projecting generally perpendicularly of the surface of the poster support plate 92. The abutment surfaces 94c enable, as will be described in greater detail below, the poster lifter assembly to move a latch 94 to the open condition to extract a prime poster from the carousel 9.

The detailed structure of a poster assembly 12 will now be described with reference to Figures 9a to 9e.

As mentioned above, each poster assembly 12 has a poster axle 121, the ends of which are adapted to be received in slots 93 in the carousel poster support plates 92. A hollow tube or former 122, generally made of aluminium, is received on the poster axle 121. A poster P is secured to and wound onto the aluminium tube 122. The poster P is generally formed of laminated paper or Mylar. End caps 123 are fitted over the ends of the poster axle 121 which allow the axle 121 to rotate about its longitudinal axis 121a relative to the tube 122. A helical spring arrangement 125 is received on the axle 121 in the space defined between the axle 121 and the tube 122. One end 125a of the helical spring arrangement 125 is secured to the axle 121 as shown most clearly in Figure 9b while the other end 125b is, as shown most clearly in Figure 9c, secured to one of the two end caps 123. The spring 125 is tensioned by the initial rolling of a poster P onto the tube 122 so that, when the poster P is unrolled, the spring arrangement 125 produces a torque tending to cause the tube 122 to rotate relative to the axle 121 to wind the poster up. The spring assembly thus ensures that the poster is held taut when it is unrolled and that it rolls up again correctly.

A free end of the poster P is rolled around and secured to a poster stick 126. The poster stick is held in position parallel to and spaced apart from the poster axle 121 by means of two poster stick support plates 127, one of which is shown in Figure 9d. Each poster stick support plate 127 has an aperture 127a shaped to receive a corresponding end of the poster axle 121 and a recess or slot 127b shaped to receive an end 126a of the poster stick 126.

As can be seen from Figure 9a each end 126a of the poster stick carries an abutment member 126b and the poster stick support plates are shaped so that the slot 127b of a poster stick support plate 127 receives a portion 126c of a poster stick between the poster P and the abutment member 126b, thereby ensuring that the poster stick 126c cannot slide out of the poster stick support 127.

The spring 125 should provide sufficient spring force to hold the poster stick 126 in the poster stick supports 127. However, as shown, a spring clip 128 may be mounted to each poster stick support plate 127 adjacent to the slot 127b to ensure that the poster stick 126 is securely retained by the poster stick support plates 127. As shown in Figure 9d, the spring clip 128 has a slightly smaller opening than the slot 127b and the slot 127b flares outwardly to facilitate locating of the end 126a of a poster stick in the slot.

Figure 9e shows, very diagrammatically, a plan view of an unrolled poster P where the poster has already been secured (for example by means of adhesive or tape or the like) to the tube 122 at one end and to the poster stick 126 at the other end but has not yet been pre-tensioned into the rolled up configuration using the spring arrangement 125.

Typically, a poster is 1860 cm wide and 3039 cm long with a viewable area VA of 1800 by 2700 cm. A portion P' of the poster P adjacent to the poster stick 126 carries a poster identification. Generally, this will include a machine readable identification code and also a code that can be read by a human operator when loading the carousel 9 with posters. Typically the machine readable poster identification code will be a barcode and the poster recognition device 14 shown in Figure 7 will be a barcode reader of conventional form.

The carousel and lifter drive arrangements will now be described in greater detail with reference to Figures 10 and 11. Figure 10 shows a part of the carousel 9 and the adjacent lower lifter pulley 104 with the lifter assembly 10 just above a lowermost position of the lifter bar 101 and carrying a prime poster Pi in a manner which will be explained in greater detail below. Figure 11 shows a portion of the mechanical assembly adjacent to the upper lifter pulley 103 when the lifter assembly 10 is nearing its uppermost position. Figure 11 also shows the lifter assembly 10 carrying a primer poster PI.

As shown in Figures 10 and 11, the carousel and lifter drive arrangements are belt and direct drive arrangements respectively. As shown in Figure 10, an endless toothed carousel drive belt 96 extends around a gear wheel 97 fixedly secured to the end 91' a (not visible in Figure 10) of the carousel axle 91 and a pulley wheel 98 mounted to an end of the carousel motor drive shaft that extends through a motor mounting plate 80 forming part of the main chassis. The carousel motor 99 is not visible in Figure 10 because it is mounted behind the mounting plate.

The position of the motor mounting plate 80 on the main chassis can be adjusted by a slot and pin 80a and 80b arrangement so as to enable the tension in the carousel drive belt 96 to be adjusted.

A lifter belt tensioning rocker arm 109a is also mounted to the main chassis to enable the tension in the toothed lifter belt 102 to be adjusted.

As shown in Figure 11, the upper lifter pulleys 103 (only one is visible in Figure 11) are mounted on a lifter axle 110 journalled to the main chassis upright members 8a. The lifter axle 110 is directly coupled to the lifter motor 105 drive shaft which extends through the upright chassis member 8a.

As can be seen from Figures 10 and 11, each end of the lifter bar 101 carries an end member 101a within which a block 101b is mounted that is secured to the lifter belt 102.

Figures 10 and 11 also show in greater detail a jaw 109 of the lifter assembly 10. The structure of the lifter jaw 109 is, however, shown more clearly in Figures 16 to 18, 21, 22 and 24 which show the cooperation between a lifter jaw 109 and a carousel poster support plate 92. It will be appreciated that both lifter jaws 109 are identical with one being a mirror image of the other.

As shown in Figure 16, each lifter jaw 109 consists of first and second lifter jaw plates 19 and 20. The first lifter jaw plate 19 carries a pin or shoulder bolt 19a which is received in an elongate slot 20a of the second lifter jaw plate 20 so enabling relative movement between the first and second jaw plates 19 and 20. A lifter cam 20i is pivotally mounted to the pin 19a. As will be explained in greater detail below with reference to Figures 21a to 21c, the lifter cam 20i cooperates with a cam striker 20k (not shown in Figure 16) mounted to a lower cross member 8e of the chassis (see Figure 5) during selection of a secondary poster. The first jaw plate 19 has, as most clearly seen in Figure 21c, a cut out portion 19b shaped to receive a poster axle 121 of a prime poster. As can be seen in Figure 21c, the cut out portion has a lip 19 'b for holding the poster axle 121 in place. The first lifter jaw plate 19 also has a first inwardly extending retaining member 19c and an aperture 19d through which a second inwardly extending retaining member 20c carried by the second lifter jaw plate 20 projects to cooperate with the first retaining member 19c to hold a poster stick 126 of a secondary poster.

The second lifter jaw plate 20 has an aperture 20b bounded by a retaining arm 20e which, as will become clear below, cooperates with the aperture 19b in the first lifter jaw plate 19 to engage an end of the poster axle 121 of a prime poster.

The first and second lifter jaw plates 19 and 20 are connected by a spring biasing mechanism (not visible in the drawings) which, as indicated by the arrow S in Figure 16, biases the second lifter jaw plate 20 downwardly with respect to the first lifter jaw plate 19 into a jaw clamped configuration in which the retaining members 19c and 20c cooperate to engage an end of a poster stick 126, if present, of a secondary poster, and the apertures 19b and 20b and retaining arm 20e cooperate to retain the end of a poster axle 121 of a prime poster, if present.

The manner in which the carousel 9 is filled or charged with poster assemblies will now be described.

As shown in Figures 1 and 6 the housing 2 has an access panel 2a immediately in front of the carousel 9 to enable a maintenance operator to charge the carousel 9 with posters or to replace existing posters with a new set of posters. The opening mechanism of the access panel is coupled to a conventional interlock mechanism 15 (see Figure 7) which is itself coupled to the processor 201 so that, when the access panel 2a is opened, operation of the carousel and lifter motors 99 and 105 is prevented and, optionally, the back lighting arrangement is switched off.

In order to charge an empty carousel 9, after opening the access panel 2a, the operative needs simply to locate the respective ends of a poster axle 121 above the opposed slots 93 exposed by opening the access panel 2a and then to push the poster axle 121 downwards into the slots 93 which, by virtue of the shaping of the noses 94b of the closure latches 94, causes the closure latches 94 to pivot against the spring biasing permitting the ends of the axle to enter the slots 93. Once the ends of the axle have passed the tips of the nose portions 94b of the respective closure latches 94, then the closure latches return, under the spring biasing force, to the spring biased position holding the poster axle 121 securely in place within the slots 93. A poster may be removed by grasping the axle and pulling the poster out.

The processor 201 of the control circuitry 201 is programmed with a carousel charging mode of operation which is initiated when the processor 201 determines, as a result of a signal from the interlock mechanism 15, that the access panel 2a has been opened. Opening the access panel 2a prohibits operation of the carousel and lifter motors and allows an operative to load or unload a poster from the pair of slots 93 exposed within the access panel. Once an operative has loaded or unloaded a poster and re-shut the access panel 2a, then the processor 201 causes the carousel motor 99 to rotate to bring the next poster to be unloaded (or the next free poster position to be loaded with a poster) to the exposed position. The proximity sensor 95 enables the processor 201 to determine when a pair of slots is located at the exposed position. The indicator panel 16 has a series of different indicators enabling the processor 201 to advise the operative when the carousel is being rotated (while the access panel 2a is closed), when the door can be re-opened and when a poster changing operation is complete. In this case, the processor 201 uses the poster recognition device 14 to determine when the poster IDs have been changed and to determine which poster ID corresponds to which position in the carousel.

Figure 12 is a flow chart showing the main steps carried out by the processor 201 when the poster display device is first activated or after the interlock mechanism 15 has sent a signal to the processor 201 that the access panel 2a has been resecured after the carousel 9 has been loaded with new posters.

Thus, at step SI, the processor 201 causes the poster recognition device 14 to read the poster ID from the poster aligned with the recognition device 14. That is, in this example the poster at the uppermost position in the carousel, and then stores that poster ID in its memory 201a.

At step S2, the processor 201 controls the carousel motor 99 via the carousel driver 99a to rotate the carousel 9 until the processor 201 determines using the proximity sensor 95 that the next poster has been brought to the uppermost position in the carousel 9 (step S2).

At step S3, the processor 201 controls the poster recognition device 14 to read the poster ID from the poster now at the uppermost position in the carousel 9 and then stores that poster ID in its memory 201a. At step S4, the processor 201 determines whether the number of poster IDs read equals the number of pairs of slots 93 in the carousel 9 (or whether a full revolution of the carousel has been completed) . If the answer at step S4 is no, then steps S2 and S3 are repeated until the answer at step S4 is yes.

When the answer at step s4 is yes, that is the processor 201 has determined that the poster IDs have been read for all posters charged into the carousel, then the processor 201 checks to see whether the poster IDs read by the poster recognition device 14 agree with the poster IDs in poster display control data stored in its memory 201a.

If the processor 201 determines at step S5 that the poster IDs read by the poster recognition device 14 do not agree with the poster IDs in the poster display control data, then the processor 201 will advise the host computer 7 via the base station 6 (step S6) that the posters in the carousel are incompatible with the poster display control data. The host computer 7 may then check the poster IDs of the posters charged in the carousel 9 of that poster display device against data stored in its memory indicating the correct poster display control data for that poster display device and, if there is a discrepancy, alert an operator who may cause the host computer 7 to transmit via the base station 6 updated poster display control data or may contact the operative responsible for charging the poster display device via, for example, his mobile telephone to advise him that the wrong posters have been charged into the carousel 9.

In addition, the interlock mechanism 15 may be arranged such that the operative responsible for charging the carousel cannot remove an access panel key until the processor 201 has determined that the correct posters have been charged into the carousel, that is until the answer at step S5 in Figure 12 is yes. This would give the operative a direct indication if he had loaded the wrong posters in error and, moreover, should prevent the operative leaving the poster display device until the correct posters have been charged into the carousel.

An authorised officer responsible for the poster display device 1 may, at any time, communicate with the poster display device via the host computer 7, base station 6 and the GSM network to change the poster display control data stored in the memory 201a of the processor 201. This need not necessarily involve changing of the posters stored in the carousel 9. Thus, for example, an authorised representative may communicate with the poster display device over the GSM network to change the time of day, date, frequency and duration of display of the posters stored in the carousel in accordance with changing requirements of the advertisers responsible for the individual posters . Figure 13 shows a flow chart illustrating the steps carried out by the processor 201 when new data is received over the GSM network.

The processor 201 is continually monitoring to check whether new poster display control data is being communicated over the GSM network. When at step S7 in Figure 13, the processor 201 determines that new poster display control data is being received over the GSM network via the GSM interface 66 (Figure 7), then the processor 201 stores that data in its memory 201a. Then, at step S8, the processor 201 checks to see if the poster IDs in the received poster display control data agree with the previously stored poster IDs read from the posters stored in the carousel 9. If the answer at step S8 is yes, then the processor 201 replaces the previously stored poster display control data with the new poster display control data received from the base station 6 so that all subsequent poster display is controlled in accordance with the new poster display control data (step S9). If, however, the answer at step S8 is no, then the processor 201 communicates over the GSM network with the base station 6 to alert the authorised officer responsible for supplying the new poster display control data that the new poster display control data is incompatible with the posters currently stored in the carousel 9 and continues to use the previously stored poster display control data (step S10) until the answer at step S8 is yes which may occur if, for example, the authorised officer sends fresh poster display control data from the control apparatus 5 or, in the meantime, the authorised officer has ensured that an operative has been despatched to the poster display device 1 and the carousel 9 has been charged with the correct posters .

It will be appreciated that an authorised officer responsible for supplying fresh poster control data need not be located at the host computer but may communicate with the host computer over the remote communications interface 76 shown in Figure 4 from his own computer.

The poster display control data will give, for each poster, the day, time and duration of each display and event for that poster. The poster display control data also indicates whether a poster is, for a particular display event, to be a prime poster or a secondary poster. The designation of a poster as a prime or secondary poster is not connected with the information provided on the poster but rather with the manner in which the posters are displayed. Thus, a prime poster is a poster that is selected so that it is displayed when the poster display device is changing from display of one secondary poster to another.

The manner in which prime and secondary posters are selected and displayed will now be described with reference to Figures 14 to 24.

Figure 14 illustrates the steps carried out by the processor 201 to control selection from the carousel 9 of a prime poster on the assumption that the carousel 9 has recently been recharged with posters and there is no prime poster currently in place.

At step Sll, the processor 201 determines from the poster display control data stored in its memory 201a the poster ID for the poster identified in that poster display control data as the prime poster.

At step S12, the processor 201 reads, using the poster recognition device 14, the poster ID of the uppermost poster in the carousel 9. At step S13, the processor 201 checks whether the poster IDs agree. If the answer is no, then the processor 201 controls the carousel motor 99 via the carousel driver 99a and using the proximity sensor 95 so as to bring the next poster to the uppermost position (step S14). Steps S12 and S13 are then repeated until the answer at step S13 is yes, that is the required prime poster is at the uppermost position in the carousel 9. At this stage the processor 201 controls the rotation carousel 9 so that the selected prime poster Pi is as shown in Figure 16, slightly offset from the uppermost position.

At step S15, the processor 201 then controls the lifter motor 105 via the lifter driver 103a to lower the lifter bar 101 to enable the lifter jaws 109 to engage the prime poster PI. As mentioned above, the travel of the lifter bar 101 is calibrated using the sensors 106 and 107 so that the processor 201 can determine the time for which the lifter motor 105 needs to be driven to bring the lifter bar to the required position.

Figure 16 shows the situation when the lifter assembly has just reached the required lower position.

As the lifter bar 101 is lowered, the ends 20f of the second lifter jaw plates 20 that project beyond the ends of the first lifter jaw plates 19 come into contact with the bosses 92a of the carousel poster support plates 92. As the lifter assembly continues to move downwardly, the bosses 92a force the second lifter jaw plates 20 upwardly against the spring biasing S, thereby moving the apertures 19b and 20b into register as shown in Figure 16 and also moving the retaining member 20c to an uppermost position within the aperture 19d.

At this stage, the slots 93 carrying the poster determined from the poster display control data to be the prime poster are offset from the uppermost position of the carousel 9. Thus, as shown in Figure 16, the uppermost position of the carousel 9 bisects the angle between two adjacent apertures 93 of a poster support plate 92. Once the processor 201 determines that the lifter bar 101 has reached the position shown in Figure 16, the processor 201 causes the carousel motor 99 to rotate the carousel 9 so that the engagement arm 20e of the second jaw plate 20 engages the projection 94c of the closure latch 94 and causes the closure latch 94 to pivot about its pivot pin against the spring biasing to the open position shown in Figure 17 and the ends of the poster axle 121 of the determined prime poster are brought into register with the aligned apertures 19b and 20b.

Then the processor 201 controls the lifter motor 105 to raise the lifter bar 101 (step S15 in Figure 14).

As shown in Figure 18, as the lifter bar 101 is raised, the bosses 92a no longer counteract the spring biasing between the first and second lifter jaw plates 19 and 20 and accordingly the second lifter jaw plates 20 return to their uppermost positions in which the ends of the prime poster axle 121 are trapped by the cooperation of the apertures 19b and 20b and are prevented from lateral movement by the end plates 20e. The prime poster is thus lifted with the lifter bar 101 and as the prime poster axle 121 leaves the slots 93 the engagement arms 20e release the closure latches 94, allowing them to return to their normally closed spring biased position as shown in Figure 18.

At this stage, the processor 201 may control the lifter motor 105 to raise the lifter bar 101 to a height at which the retaining members 19c and 20c can receive the end of a poster stick 126 of a secondary poster when that secondary poster is at the uppermost position of the carousel. In this example, the microprocessor 201 determines the time for which the lifter drive motor 105 needs to be driven to reach a predetermined position on the basis of calibration information defining the distance between the upper and lower sensors 106 and 107 and the time taken by the lifter motor 105 to drive the lifter bar 101 between the upper and lower sensors 106 and 107. Alternatively, a shaft encoder could be associated with the lifter motor 105.

As an alternative to immediately raising the lifter bar 101 to a location to select a secondary poster, the processor 201 may, as indicated at step S15a in Figure 14, cause the lifter bar 101 first to be raised to an uppermost position so as to install the poster stick 126 of the prime poster PI in the prime poster support 11.

The manner in which the poster stick 126 of the prime poster PI is installed in the prime poster support 11 will now be described with reference to Figures 19 and 20.

Figure 19 shows the lifter bar 101 carrying the prime poster PI as it is just about to reach the prime poster support 11. As shown in Figure 19, the prime poster support comprises a cross bar 11a and, for each end of the poster stick 126, a guide member lib (only one is shown) mounted to the chassis cross member 8d and defining an outwardly flaring guide slot ll'b for ensuring that the end of the poster stick 126 is located in the correct position. The cross bar 11a, as shown diagrammatically in Figure 5, is mounted to the chassis 8 so as to be rotatable about its axis. A claw member lie is associated with each guide member and a locking quadrant lid is mounted at one end of the cross bar 11a so as to rotate with the cross bar 11a. A latching bolt lie is associated with the locking quadrant lid and is biased by a spring llg and a solenoid llf arrangement.

As the lifter bar 101 moves upwards, each end of the prime poster stick 126 is received in the corresponding guide lib and as it moves into the guide slot ll'b abuts a nose 11" c of the corresponding claw. As the lifter bar 101 continues to move upwards, the ends of the prime poster stick 126 cause the claws lie, and thus the cross bar 11a and locking quadrant lid, to rotate in the clockwise direction in Figure 19 until the locking quadrant lid reaches the position shown in Figure 20 at which the sprung solenoid bolt lie locks into a slot ll'd (Figure 19) in the locking quadrant. At this stage, as shown in Figure 20, the poster stick of the prime poster is securely held in position by the prime poster support 11.

When the lifter bar 101 is subsequently lowered under the control of the processor 201, the poster stick 126 is held securely by the prime poster support 11 so that, as shown in Figure 24, the poster stick 126 is released from the spring clips 128 retaining the poster stick in the poster stick supports 127 and the poster axle 121 travels downwardly with the lifter bar 101, thus unrolling the prime poster PI until the prime poster is completely unrolled and displayed in the display window 3 of the poster display device.

Selection of a secondary poster will now be described with reference to Figures 15 and 21a to 21c, 22 and 23. Generally, as will be appreciated from the above, when a secondary poster is being selected, then a prime poster will already have been selected and the poster axle 121 of the prime poster will be held by the apertures 19b and 20b of the lifter jaws 109. However, in order to show more clearly the selection of a secondary poster, the prime poster has been omitted from Figures 21 to 23.

Referring first to Figure 15, at step S16 the processor 201 determines from the poster display control data stored in its memory 201a, the secondary poster to be displayed.

When the poster 201 has determined at step SI6 the secondary poster to be selected from the carousel 9, then the processor 201 causes the carousel motor 99 to rotate the carousel 9 so that the required secondary poster is offset from the uppermost position of the carousel in an anti-clockwise direction as shown in Figure 21 (step S17).

The processor 201 then causes the lifter motor 106 to lower the lifter bar 101. Figure 21a shows part of the carousel and lifter assembly as the lifter bar 101 is lowered and just before the cam 20i reaches the cam striker 20k. As the lifter bar 101 is lowered further, the cam 20i hits the cam striker which causes the cam 20i to rotate to the position shown in Figure 21b moving the first and second lifter jaw plates 19 and 20 apart against the spring biassing so causing the retaining members 19c and 20c to move apart slightly to enable acceptance of a poster stick 126. At this stage the lifter bar 101 is at a position at which the retaining members 19c and 20c would be aligned with the end of a poster stick 126 if the poster stick were located at the uppermost position of the carousel 9 (step S18). It will be appreciated that as the lifter bar 101 is lowered to bring the retaining members 19c and 20c into the poster stick alignment position, the prime poster will be unrolled so that the prime poster is displayed while the secondary poster is being selected. The processor 201 then causes the carousel motor 99 to rotate the carousel 9 in the anti-clockwise direction shown in Figure 21b to bring the ends of the poster stick 126 of the selected secondary poster P2 into a position between the retaining members 19c and 20c of the two lifter jaws (step SI9) as shown in Figure 21c. It will, of course, be appreciated that the processor 201 determines when the poster stick 126 has been correctly positioned between the retaining members 19c and 20c by using the proximity sensor 95 to sense the location of the bolt heads 96 and supplying to the stepper motor forming the carousel motor the number of drive pulses required to rotate the carousel. Once the processor 201 has determined that the poster stick 126 has been retained by the retaining members 19c and 20c, the processor 201 controls the lifter motor 106 to cause the lifter bar 101 to be raised. As the lifter bar 101 moves upwardly the cam 20i is disengaged from the cam striker 20k and the spring biassing acts to cause the retaining members 19c and 20c to move together to hold the poster stick as shown in Figure 22. As the lifter bar 101 is raised to its uppermost position the secondary poster is unrolled to display it in the display window 3 (step S20) .

Figure 23 illustrates diagrammatically the unrolling of a secondary poster P2 as the lifter bar 101 with the secondary poster stick 126 retained in its jaws 109 is raised towards its uppermost position.

The poster display device 1 continues to display that particular secondary poster until, at step S21 in Figure 15 the processor 201 determines that the display period for that secondary poster has finished. At this stage, the processor 201 returns to step S16 and determines from the poster display control data in its memory 201a the next secondary poster to be displayed after the prime poster has been displayed for the display period or duration determined by the poster display control data.

As can be seen from a comparison of Figures 23 and Figure 24, the difference in installation between a prime and a secondary poster is that, in the case of the prime poster PI, the poster axle 121 is carried by the lifter jaws 109 while the poster stick 126 is clamped in position by the prime poster support 11 while in the case of the secondary poster P2, the poster axle 121 remains engaged in the carousel 9 and the poster stick 126 is carried by the lifter jaws 109. This means, as shown in Figure 24 that, when both a prime PI and a secondary P2 poster are engaged with the lifter bar 101, moving the lifter bar 101 upwards (step S20 in Figure 15) causes the prime poster PI to be rolled up and the secondary poster P2 to be unrolled for display in the display window 3 while moving the lifter bar 101 down (step SI8 in Figure 15) causes the secondary poster to be rolled up onto its axle 121 in the carousel 9 and the prime poster to be unrolled to be displayed in the display window 3.

When a secondary poster is to be released, the steps shown in Figures 21a to 21c, 22 and 23 are carried out in reverse. Thus, the lifter bar 101 is lowered to return the poster stick 126 to its position engaged in the poster stick supports 127 and the processor 201 then controls the carousel motor 99 to rotate the carousel in the anti-clockwise direction in Figure 21a so that the poster P2 is returned to the position shown in Figure 21a. In order to select the next secondary poster, the carousel is rotated such the ends of the poster stick 126 of each poster pass between the retaining members 19c and 20c (held open by the cooperation of the cam 20i and cam striker 20k) in turn until the required secondary poster is located between the retaining members, at which stage the processor 201 will cause the lifter bar 101 to be raised to raise the poster stick for that secondary poster.

When the processor 201 determines that the prime poster Pi is to be changed, then the processor 201 ensures that the lifter bar 101 is in its uppermost position as shown in Figure 20 and then causes the solenoid llf to act against the spring-biassing to release the latching bolt lie from the slot ll'd thus freeing the claws lie to rotate in a direction allowing the poster stick 216 of the prime poster Pi to be released from the claws lie and to return to the slots 127b in the poster stick supports 127. The prime poster can then be returned to the carousel 9 by the processor 201 causing the operation described above to be carried out in reverse. A new prime poster can then be selected in a manner described above.

As mentioned above, the access panel 2a enables an operative to replace the posters in the carousel 9 with new posters. The front or cover portion 2c of the housing may be designed to separate from the back wall and chassis of the housing 2 so as to enable maintenance of the poster display device. Figure 25 shows a very schematic side view of the front or cover portion 2c of the housing. As shown an upper hinge or pivot HI connects the side of the front cover to a corresponding side of a rear position 2d including the chassis and a telescopic lower hinge (for example a gas hinge) H2 enables the cover portion 2c to be lifted away to enable access to the mechanical and electrical components for maintenance. Similar hinges HI and H2 are provided at the other side of the housing.

As mentioned above, poster display control data is supplied to the poster display device from the host computer 7 via the base station 6. The host computer 7 and base station 6 may be in communication, via the GSM network, with a large number of poster display devices 1 enabling poster display control data tailored to a specific poster display device to be communicated to that poster display device from the base station 6. A person authorised to control operation of a poster display device 1 may be located at the host computer 7 or may be connected to the host computer, as described above, by the remote communications interface 15.

The manner in which an authorised user may change poster control display data for individual poster display devices 1 will now be described in greater detail with reference to Figures 26 to 30.

In order to change the poster display control data for one or more poster display devices 1, an authorised user must either be present at the host computer 7 or log on to the host computer 7 via the remote communication interface 76. Initially, the authorised user will be requested to enter a user ID and their password to avoid unauthorised tampering with the poster display control data and also to enable the host computer 7 to keep a record of who last changed the poster display control data for a particular poster display device.

Once the authorised user has entered his user ID and password, then the host computer 7 will request the user to select the poster display device for which he wishes to change the poster display control data (step S30) in Figure 26. At this stage, the host computer (the remote computer where a user is logged onto the host computer 7 via the remote communications interface 76) will display to the user a display such as the display screen 39 shown in Figure 27a requesting the user to select the poster display device for which he wishes to change the poster display control data.

When the device has been selected, then the host computer 7 (or the remote computer if the user is logged on remotely) will request the user at step S31 in Figure 26 to select a poster whose poster display control data is to be altered by, for example, displaying the screen 40 shown in Figure 27b. As shown, this screen has data input windows 41, 42, 43, 44 and 45 for enabling a user to input a poster ID, whether a poster is to be a prime or secondary poster, display days, display times and duration of each display respectively.

Each of these windows may enable a user to input data using a keyboard of the user input device 64 if the user is located at the host computer (or of the user input device of the remotely logged-on computer). Alternatively, each of the windows may, as is well known in the art, consist of a dropdown menu that displays a number of options to a user so that, for example, in the case of the selection of the days on which a poster is to be displayed, the user may be presented with the names of the days of the week and ask to select the required days. The windows 43 and 44 may be interlinked so that a user can select different display times for different days of the week.

The screen 40 also prompts the user to advise the host computer (or remote computer) whether they wish to change the poster display control data for another poster by clicking on either yes or no at the bottom of screen 40. When the computer determines at step S32 that the user has selected yes, then step S31 is repeated enabling the user to select another poster and modify its display control data.

When the user has finished changing poster display control data for a particular poster display device and has advised the computer by clicking on NO in screen 40, then the computer transmits the poster display control data to the base station 6 (via the host computer 7 in the case of a remote computer) for transmission to the selected poster display device at step S33. Then at step S34, the computer waits for a return acknowledgement communication from the poster display device via the base station 6 confirming receipt of the new poster display control data.

If the communication received from the poster display device 1 indicates that the received poster IDs are compatible with the poster IDs of the posters currently stored in its carousel 9, then the host computer 7 (or remote computer) proceeds to step S35 and causes the user to be prompted by, for example, screen 46 shown in Figure 27c to advise the computer whether they wish to change the poster display control data for another poster display device. If the answer at step S35 is yes, then steps S30 to S35 are repeated until the answer at step S35 is no when the authorised user will be logged off and the host computer will wait a further log in by the same or a different authorised user.

If the answer at step S34 is no, that is the poster display device 1 has advised the host computer 7 of an inconsistency between the received poster IDs and the poster IDs for the posters stored in the carousel 9, the host computer 7 (or remote computer) will advise the user accordingly at step S36 by, for example, displaying the screen 47 shown in Figure 27d which advises the user that the poster IDs are inconsistent and gives the user an opportunity to correct the input poster display control data. If, at step S37 in Figure 26, the user has indicated that correction is required, then the computer returns to step S31 in Figure 37. If, however, the user indicates that no correction is required, then the computer returns to step S30 awaiting further input. In this case the authorised user will dispatch an operative to the poster display device 1 to ensure that the posters are changed. The poster display device will continue to operate using the previously received poster display control data until such time as the carousel 9 has been charged with the correct posters.

The host computer 7 retains in its memory (generally on the hard disk drive 72) a database including the poster display control data for each poster display device 1 and information associating the posters being displayed with the persons responsible for those posters, that is the advertisers displaying the posters. Any suitable conventional form of database may be used. Generally the database will be a relational database.

Figures 28a to 28d show examples of tables indicating how data may be stored in the database on the hard disk drive 72. Figure 28a shows a data store 50 which associates an ID for each display device with the IDs for the posters currently stored in the carousel of that display device and Figure 28b a table 51 associating each poster ID with information identifying the advertiser responsible for that poster, for example the advertisers name, address and telephone number. As shown in Figure 28c, the database also includes, for each poster display device, a poster display control data table 52 which includes a section for each poster ID currently associated with that poster display device. Each poster ID section has a poster ID field 53 for receiving the poster ID, display day(s) fields 54 for identifying the days of the week on which the poster is to be displayed, display time(s) fields 55 for identifying for each day of the week the times at which that particular poster is to be displayed and display duration fields 56 identifying for each display time the duration of display. The poster display control data table 52 may also include, for each individual display of a poster, a charging rate field 57 identifying the amount the advertiser is to be charged for that particular display.

The poster display control data table 52 also identifies when a poster is to be a prime poster. As shown this is identified by the symbol "P" in the time field 55. Only one poster can be designated "P" at any one time.

The database also includes a respective table 60 for each advertiser having poster display device sections 61, each having poster ID, day(s), time(s), duration and charge rate fields which enable, as will be appreciated, individual advertisers to be provided with itemised invoices which provide them with information confirming the days, times and duration for which each of their posters have been displayed on each of the poster display devices to which their posters have been allocated together with itemised billing information for those display events .

As will be appreciated from the above, the information in the poster display control data table 52 for a particular poster ID will be updated each time an authorised user carries out the steps set out in Figure 26 ready for transmission to the relevant poster display device which will store a table similar to Figure 28c but omitting the charge rate.

Figure 29 shows the steps carried out by the base station 6 during communication with a poster display device 1. Thus, at step S50, the base station 6 receives from the host computer 7 data identifying the poster display device whose poster display control data is to be changed together with the new poster display control data. At step S51, the base station establishes communication with the selected poster display device via the GSM network and at step S52 transmits the poster display control data to the poster display device. The base station waits for acknowledgement from the poster display device at step S53. If no acknowledgement is received, then, as shown in Figure 29, the base station 6 checks at step S54 whether the poster display data has also been transmitted a number, in this example three, times. If the answer is no, then the base station returns to step S52. If, however, the answer at step S54 is yes, then the base station 6 communicates with the host computer 7 to indicate that there has been a failure in the data transmission at step S55. The host computer may then advise the authorised user of this failure so that the authorised user can, for example, send a maintenance engineer to the poster display device.

If the answer at step S53 is yes, then the base station 6 checks at step S56 whether it has received from the poster display device a communication indicating that the poster IDs in the received poster display control data are consistent with poster IDs of the posters stored in the carousel of that poster display device and then transmits, at step S57, this information to the host computer 7 so that the host computer can advise the authorised user as set out above.

The host computer 7 may also be configured to request periodic status reports from each poster display device so that the host computer can be advised immediately of any faults determined by the processor 201 of a poster display device so that a maintenance engineer can be despatched.

In the above described embodiment, the base station 6 is provided separately from the host computer 7. This need not, however, necessarily be the case and all the functions of the base station 6 and host computer 7 may be carried out by a single work station. In the above described embodiments, communication between the poster display devices 1 and the base station 6 is effected over the GSM network using the GSM data transmission protocols. However, other forms of remote communication may be used. For example, where the environment permits, the remote communication link may be radio link. As another possibility, the poster display devices in a local area may be coupled to a local base station via a network arrangement. As yet another possibility, remote communication between the base station and the poster display devices may be effected over a fixed landline telecommunications service and the fixed landlines may be landlines dedicated to the poster display device.

In the above described embodiments, the lifter bar and the carousel are driven using direct and belt drive arrangements, respectively, driven by electric motors. These arrangements may, however, be replaced by other types of drive arrangements such, as for example, chain drive arrangements or a rack and pinion drive arrangements. Furthermore, the lifter bar electric drive may be replaced by a hydraulic or pneumatic drive arrangement whereby the lifter bar is raised and lowered by a pneumatically or hydraulically extendable and retractable piston arrangement. Similarly, as will be understood by those skilled in the art a pneumatic or hydraulic drive may be used to rotate the carousel 9. Also the sensors described above need not be proximity sensors but could be, for example, optical sensors.

In the above described embodiments, the carousel 9 is charged manually by an operative. A poster display device may, however, additionally include a hopper of replacement posters from which a poster changer unit operating in a similar manner to the lifter assembly can extract posters and transfer them to the carousel. The posters may be stored in the hopper on an endless belt arrangement.

As shown in Figures 1 and 25, the housing is provided with an access panel 2a for enabling changing of the posters by an operative and the front portion may be hinged outwards for maintenance. As other possibilities, the front portion 2c of the housing may either, as shown in Figure 30, be releasably secured to the remainder of the housing so that the entirety of the front portion 2c may be completely removed or may be hingedly connected to the remainder of the housing so as to enable, as shown in Figure 31, the front panel to be opened to enable access to the interior of the housing. In each case, security latches would hold the front portion 2c of the housing in a closed condition during use.

In the above described embodiments, the carousel drive motor is a stepper motor and the control over the rotation of the carousel is determined by the number of step pulses supplied to the motor. As another possibility a shaft encoder may be mounted to the chassis and used to measure rotation of the carousel axle. Any conventional form of shaft encoder may be used. For example, the shaft encoder may comprise a slotted disk which is carried by and rotates with the carousel drive motor drive shaft and which interrupts the light path between the light emitting and light receiving device of an optocoupler.

In the above described embodiments, the poster display devices are arranged to be controlled remotely. However, the poster display device 1 may be a stand-alone device. In this case, the poster display control data will be stored directly in the memory 201a of the control circuitry 200 and the GSM interface may be replaced by, for example, a removable disk disk drive or interface for enabling downloading of replacement processor display control data directly into the memory 201a by an operative located at the poster display device. As another possibility, the poster display device may be provided with a completely electromechanical timing and control arrangement for selecting and displaying the posters .

Figure 32 illustrates another example of a poster storage and transport mechanism that may be used in a poster display device embodying the invention. Figure 32 shows a cut-away side elevational view of the poster storage and supply mechanism. In this example, a respective continuous transport track 950 runs around each side of the interior of the housing and stored posters P are supported between guides 951. Each poster P has top and bottom poster rails 952 with a pick up mechanism 953 being used to select a particular poster P and to move an end of its uppermost poster rail into a poster rail 952 engagement section 950a in both of the transport tracks 950. Rotation of the transport track by a motor (not shown) causes the selected poster to be moved out of its guides 951 and along the transport track 950 to a location immediately behind the display window 3 of the poster display device. In this example, a reflector R is provided to improve the back illumination from a pair of long life light bulbs B. Figure 32 shows a first poster P3 being moved to and a second poster P4 being moved from a position immediately behind the display window 3.

It will be appreciated that the remote control system for changing the poster display control data described above may be used with other poster display devices which do not allow such flexibility in the display of posters. For example, the remote communication of the poster display control data may be implemented with poster display devices wherein the posters are fixedly mounted on an endless belt. In this case, the poster display control data will control the time for which each poster mounted on the endless belt is displayed and, for example, the direction in which the endless belt is driven so that the posters can be displayed in forward or reverse sequence, depending upon the direction in which the endless belt is driven. As a variant on this, the posters may be removably attached to the endless belt so that the posters can be manually changed. The remote communication of poster display control data may also be used with conventional display system wherein the poster display arrangement consists of three-faced rotatable poster display elements as described above.

In the above described embodiments, the poster display device uses a back lighting system. Where ambient lighting is sufficient the back lighting system may be omitted. In addition, other forms of back lighting systems in addition to fluorescent lights may be used. Where discrete lighting sources are used, then a light diffuser may be provided between the light sources and the poster to ensure even illumination.

In the above described embodiments, the poster display area is 3 metres by 2 metres. The present invention, may however, be applied to smaller or larger poster display areas with the same three:two aspect ratio or different aspect ratios. In the above described embodiments the poster display device form is intended to be wall mounted. The poster display device may, however, be arranged to free-standing using suitable outdoor structural support arrangements.

In the above described embodiments, the poster display device is intended to be used outdoors. However, the poster display device may be used indoors. In addition, the posters need not necessarily carry preformed images and text but may present surfaces that can be written upon by a user in a manner similar to a whiteboard. Such an arrangement may be used to replace an existing whiteboard so that a person or persons using the whiteboard do not need to erase information written onto the whiteboard but can store it for later retrieval and access a fresh poster to provide a clean writing surface. A user may also provide a presentation by controlling the rotation of the carousel, for example by programming the processor 201, to display pre-drawn posters in a predetermined order.

Other modifications would be apparent to persons skilled in the art.

Claims

CLAIMS :

1. A poster display device comprising: a housing having a display window for displaying a poster, the housing containing: a poster store for storing a plurality of posters; a poster selecting means for selecting any one of the posters from the poster store; and a poster displaying means for moving a selected poster to a display position at which the poster is visible through the display window.

2. A poster display device according to Claim 1, further comprising store means for storing poster display control data and control means for controlling the poster selecting means in accordance with the poster display control data.

3. A poster display device according to Claim 2, further comprising communication means for communicating with a control apparatus to receive poster display control data from the communication means and means for storing received poster display control data in said store means.

4. A poster display device according to Claim 1, further comprising communication means for communicating with a control apparatus to receive poster display control data from the communication means and control means for controlling the poster selecting and displaying means in accordance with the poster display control data.

5. A poster display device according to Claim 3 or 4, wherein the communication means comprises remote communication means for communicating with a control apparatus located away from the poster display device.

6. A poster display device according to Claim 5, wherein the remote communication means comprises wireless communication means.

7. A poster display device according to Claim 6, wherein the remote communication means is adapted to communicate with the control apparatus using the GSM network.

8. A poster display device according to any one of the preceding claims, wherein the poster store comprises a rotatable carousel having a plurality of poster storage locations spaced apart around its periphery for enabling a plurality of posters to be stored spaced apart around the carousel periphery each rolled up about a poster axis with the poster axes being parallel to the carousel rotation axis.

9. A poster display device according to Claim 8, wherein each poster storage location comprises a poster receiving slot and a closure latch biassed by biassing means so as to close the slot to retain a poster in engagement with the carousel.

10. A poster display device according to Claim 9, wherein each closure latch has a shaped portion adapted to cooperate with a poster to cause the closure latch to move against the biassing force of the biassing means by pressure exerted by the poster to enable the poster to be engaged in the slot, the arrangement being such that once the poster is engaged with the slot, the biassing means returns the closure latch to the closed position.

11. A poster display device according to Claim 8, 9 or 10, wherein the carousel comprises a carousel axle having spaced apart along its length two carousel plates each of which carries around its periphery a plurality of spaced apart poster storage locations, with the two carousel plates being arranged to define pairs of aligned poster storage locations with the poster storage locations of a pair being arranged to receive opposite ends of the same poster.

12. A poster display device according to any one of claims 8 to 11 wherein the poster selecting means comprises carousel drive means for rotating the carousel to bring a selected poster to a poster retrieval position.

13. A poster display device according to any one of the preceding claims, wherein the poster selecting means comprises engaging means for engaging a part of a poster and moving means for moving the engaging means away from the poster store so as to unroll the poster for display in the display window.

14. A poster display device according to any one of the preceding claims, wherein the poster selecting means comprises first engaging means for engaging a first part of a prime poster and a second part of a secondary poster, moving means for moving the engaging means away from the poster store so that as the first engaging means is moved away from the poster store the prime poster moves with the engaging means and the secondary poster is unrolled for display in the display window and second engaging for engaging a part of the prime poster when the secondary poster is unrolled such that movement of the moving means back towards the poster store causes the prime poster to unroll so as to be displayed in the display window and the secondary poster to be rolled up again.

15. A poster display device according to any one of Claims 8 to 12, wherein the poster selecting means comprises first engaging means for engaging a first part of a prime poster and a second part of a secondary poster, moving means for moving the engaging means away from the poster store so that as the first engaging means is moved away from the poster store the prime poster moves with the engaging means and the secondary poster is unrolled for display in the display window and second engaging for engaging a part of the prime poster when the secondary poster is unrolled such that movement of the moving means back towards the poster store causes the prime poster to unroll so as to be displayed in the display window and the secondary poster to be rolled up again.

16. A poster display device according to Claim 15, wherein the first engaging means comprises first and second jaws spaced apart in a direction parallel to the carousel axis for each engaging respective ends of posters .

17. A poster display device according to Claim 16, wherein each jaw comprises first and second jaw plates having first and second cooperating means for engaging said first part of a prime poster and third and fourth cooperating means for engaging said second part of a secondary poster and jaw plate biassing means for biasing the first and second plates into relative positions in which the first and second cooperating means adopt a closed condition and the third and fourth cooperating means adopt a closed condition, the second and second jaw plates being moved relative to one another to cause the first and second cooperating means adopt an open condition and the third and fourth cooperating means to adopt an open condition when one of said first and second jaw plates of a jaw abuts a corresponding cooperating part of the carousel.

18. A poster display device according to claim 17, wherein the first and second engaging parts comprise respective slots provided in the first and second jaw plates and the third and fourth engaging parts comprise respective engagement members projecting from the first and second jaw plates with the second engaging member extending through an aperture in the first engaging member.

19. A poster display device according to Claim 17 or 18 when dependent on claim 11, wherein said cooperating parts comprise bosses of the carousel plates.

20. A poster display device according to any one of claims 14 to 19, wherein said second engaging means comprises first and second spaced apart claw members carried by a rotatable support bar which also carries a locking member, the claw members being arranged to cause the support bar to rotate when the free end of a prime poster engages the claw members thereby causing the locking member to rotate to a locking position in which it is locked in place by locking means thereby securing the free end of the prime poster to the support bar.

21. A poster display device according to claim 20, wherein the locking means comprises a solenoid biassed bolt received in a locking aperture of the locking member.

22. A poster display device according to any one of the preceding claims in combination with at least one poster, wherein the poster comprises: a poster axle; a poster former carried by the poster axle; a poster sheet wound onto the former about the poster axle so as to have a free end extending generally parallel to the poster axle; poster biassing means coupled between the poster axle and the poster former so as to bias the poster into a condition in which the poster is rolled up onto the poster former; and a poster end support for supporting the free end of the poster relative to the poster axle.

23. A poster display device according to claim 22 when dependent on claim 14 or 15, wherein said first part of a poster comprises the ends of the poster axle and the second part of a poster comprises said free end.

24. A poster display device according to claim 23, wherein said free end carries a poster stick.

25. A poster display device according to claim 24, wherein the poster end support comprises first and second spaced apart support members for holding the poster stick.

26. A poster display device according to claim 25, wherein each support member has a recess for receiving a part of the poster stick and spring biassing means for retaining the poster stick in the recess.

27. A poster display device according to any one of claims 22 to 26, wherein the poster carries a poster ID and the poster display device comprises poster ID reading means .

28. A poster display device comprising: a housing having a display window for displaying a poster, the housing containing: a poster store for storing a plurality of posters; a poster displaying means for moving a selected poster to a display position at which the poster is visible through the display window; remote communication means for communicating with a control apparatus located away from the poster display device to receive poster display control data from the communication means; and control means for controlling the poster displaying means in accordance with the poster display control data.

29. A poster display device according to Claim 28, wherein the remote communication means comprises wireless communication means.

30. A poster display device according to Claim 29, wherein the remote communication means is adapted to communicate with the control apparatus using the GSM network.

31. A poster display device according to any one of claims 2 to 7 or claims 8 to 27 when dependent on any one of claims 2 to 7 or any one of claims 28 to 30, wherein the communication means is arranged to receive poster display control data which includes at least one poster identification identifying a particular poster and, for that poster, information identifying at least one of a day, time and duration for which that poster is to be displayed.

32. A system comprising: at least one a poster display device according to claim 3, or any one of claims 8 to

27 when dependent on claim 3, or claim 28; and a control apparatus having communication means for communicating with the at least one poster, the communication means comprising: receiving means for receiving poster display device identifying data and poster display control data; poster display identifying means for identifying the poster display device to which the poster display control data is to be communicated from the received data; and transmitting means for transmitting the poster display control data to the identified poster display device.

33. A system according to Claim 32, wherein the communication means comprise wireless communication means .

34. A system according to Claim 32, wherein the communication means are adapted to communicate using the GSM network.

35. A system according to any one of claims 32 to 34, wherein the communication means are arranged to communicate poster display control data which includes at least one poster identification identifying a particular poster and, for that poster, information identifying at least one of a day, time and duration for which that poster is to be displayed.

36. A control apparatus for use in a system in accordance with claim 32, the control apparatus having communication means for communicating with the at least one poster, the communication means comprising: receiving means for receiving poster display device identifying data and poster display control data; poster display identifying means for identifying the poster display device to which the poster display control data is to be communicated from the received data; and transmitting means for transmitting the poster display control data to the identified poster display device.

37. A control apparatus according to Claim 36, wherein the communication means comprise wireless communication means .

38. A control apparatus according to Claim 36, wherein the communication means are adapted to communicate using the GSM network.

39. A control apparatus according to any one of claims 36 to 38, wherein the communication means are arranged to communicate poster display control data which includes at least one poster identification identifying a particular poster and, for that poster, information identifying at least one of a day, time and duration for which that poster is to be displayed.

40. A signal carrying processor implementable instructions for causing a processor to be configured to carry out processor operations of a poster display device according to any one of claims 1 to 31 or processor operations of a control apparatus according to any one of claims 36 to 39.

41. A storage medium carrying processor implementable instructions for causing a processor to be configured to carry out processor operations of a poster display device according to any one of claims 1 to 31 or a control apparatus according to any one of claims 36 to 39.

42. A poster assembly for use in a poster display device according to any one of claims 1 to 31, the poster assembly comprising: a poster axle; a poster former carried by the poster axle; a poster sheet wound onto the former about the poster axle so as to have a free end extending generally parallel to the poster axle; poster biassing means coupled between the poster axle and the former so as to bias the poster into a condition in which the poster is rolled up onto the poster former; and a poster end support for supporting the free end of the poster relative to the poster axle.

43. A poster assembly according to claim 42, wherein said free end carries a poster stick.

44. A poster assembly according to claim 43, wherein the poster end support comprises first and second spaced apart support members for holding the poster stick.

45. A poster assembly according to claim 44, wherein each support member has a recess for receiving a part of the poster stick and spring biassing means for retaining the poster stick in the recess.

46. A poster assembly according to any one of claims 42 to 45, wherein the poster carries a poster ID.