Abstract:
A display apparatus has a roll of film with multiple still images disposed along the roll of film. The roll of film is scrollable by one or more electric motors to display one or more of the still images on the roll of film at a visual display location. The display apparatus includes control equipment which is capable of identifying individual still images on the film separate and apart from that still image&#39;s relative location along the length of the film.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to display apparatuses and, more particularly, to display apparatuses capable of displaying different images.  
         BACKGROUND OF THE INVENTION  
         [0002]    Display apparatuses capable of displaying different images are becoming increasingly popular, especially as advertising devices. Using such a display apparatus, a media group can frequently change the advertisement image on display. This gives the media group the ability to advertise a client&#39;s product or services using many different images. It also gives the media group the ability to use the display apparatus to advertise the products and services of a large number of different clients.  
           [0003]    The most cost-efficient and reliable form of such display apparatuses employ a roll of film to which has been applied a plurality of individual still images. The roll of film is disposed within a display structure having two or more vertically spaced-apart parallel rollers. The space between the rollers provides a visual image display location. When a particular still image is desired to be displayed, the film is scrolled until the desired image is properly centered within the visual display location. Typically, the roll of film is scrolled using one or more scrolling motors controlled by some form of sensor/controller.  
           [0004]    There are several problems with presently available display apparatuses of the type described above. One problem arises from the fact that the sensor/controller typically controls the scrolling of the film by attempting to “keep track” of the relative position of each still image on the film. For example, a typical controller is programmed to note that the twelfth still image on a roll of film, is just that, the twelfth image on the roll of film. If the controller believes that the image presently being displayed at the display location is the fourth still image on the roll of film, and that the twelfth still image is desired to be displayed at the display location, the controller controls the scrolling of the film until the film is advanced by eight still images. The problem with this method of controlling the scrolling of the film is that, if the controller mistakenly believes that the image being displayed at the display location is the fifth still image (instead of the fourth still image), the controller will scroll the film only seven still images in its attempt to place what the controller believes to be the twelfth still image within the display location. However, because the controller was “mistaken” regarding what still image was initially being displayed within the display location, the scrolling of the film by seven still images causes the eleventh still image to be displayed at the display location (not the twelfth still image). What is more, once the controller makes such a mistake as to where the film is with respect to the display location, it will remain “mistaken,” until the mistake is realized by an operator.  
           [0005]    Another problem with display apparatuses of the type described above is that the image displayed at the display location is static, and therefore does not necessarily attract attention. While the film is being scrolled to a new display image, the sign catches the eye of the observer, but once the image is properly centered at the display location, the image becomes stationary and is no longer interesting to the eye of the observer.  
           [0006]    A third problem with such display apparatuses has to do with the most common way of braking the scrolling means to stop the scrolling of the apparatus when the desired still image has becomes properly centered within the display location. Most scrolling mechanisms employ some form of mechanical brake to slow and stop the scrolling of the film. However, mechanical brakes are prone to wear, and thus require frequent maintenance and/or replacement.  
           [0007]    Accordingly, there is a need for a display apparatus capable of displaying different images which avoids the aforementioned problems with the prior art in an economically efficient and operationally reliable way.  
         SUMMARY OF THE INVENTION  
         [0008]    The invention satisfies this need. The invention is a display apparatus comprising (a) a display structure, having a visual display location for displaying a desired still image, (b) a roll of film having at least two still images set forth thereon, each image being displayable at the visual display location, (c) scroll means for alternatively scrolling the film forwards and backwards to align a desired image at the visual display location, (d) control means for controlling the scroll means to align a desired image at the visual display location. The control means includes means for identifying individual still images on the film separate and apart from that still image&#39;s relative location along the length of the film.  
           [0009]    In a preferred embodiment, the scroll means includes braking means which rely principally upon dynamic braking to slow and eventually stop the scrolling of the film. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0010]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where:  
         [0011]    [0011]FIG. 1 is an exploded isometric view of a display apparatus having features of the invention;  
         [0012]    [0012]FIG. 2 is a side view of the assembled display apparatus illustrated in FIG. 1;  
         [0013]    [0013]FIG. 3 is a front view of the display apparatus illustrated in FIG. 2;  
         [0014]    [0014]FIG. 4 is a rear view of the display apparatus illustrated in FIG. 2;  
         [0015]    [0015]FIG. 5 is a side view of the display apparatus illustrated in FIG. 2, showing the addition of a roll of film and a cover shroud;  
         [0016]    [0016]FIG. 6 is a front view of the display apparatus illustrated in FIG. 5;  
         [0017]    [0017]FIG. 7A is a rear view of the display apparatus illustrated in FIG. 5;  
         [0018]    [0018]FIG. 7B is an alternative rear view of the display apparatus in FIG. 5, showing the use of a fifth idler roller;  
         [0019]    [0019]FIG. 7C is a second alternative rear view of the display apparatus in FIG. 5, showing the use of a separate oscillator;  
         [0020]    [0020]FIG. 8 is a side view of a cover shroud useable in the invention; and  
         [0021]    [0021]FIG. 9 is a top view of the cover shroud illustrated in FIG. 8. 
     
    
     DETAILED DESCRIPTION  
       [0022]    The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.  
         [0023]    The invention is a display apparatus  10  comprising a display structure  12 , a roll of film  14  carrying a plurality of still images  28 , scroll means  16  for scrolling the film and control means  18  for controlling the scroll means  16 .  
         [0024]    The roll of film  14  has at least two still images  28  disposed thereon, more typically, at least  10  still images  28 , and frequently more than  30  still images  28 .  
         [0025]    In the embodiment illustrated in the drawings, the display structure  12  comprises a pair of support members  22 . The support members  22  can be opposed plates, typically made from a lightweight metal such as a thin steel.  
         [0026]    The roll of film  14  can be made from any suitable rollable material. Films made of plastic can be used. Films made of fabric, either woven or non-woven, can also be used. The first end is attached to a first take-up spool  24  and is partially wound around the first take-up spool  24 . The second end is attached to a second take-up spool  26  and is partially wound around the second take-up spool  26 . Each take-up spool  24  or  26  has a spool flange  27  disposed at each of its opposed two ends to retain the film on the take-up spool  24  or  26 . The first take-up spool  24  and the second take-up spool  26  are disposed in parallel and are both supported at their opposite ends by the two support members  22 .  
         [0027]    In the embodiment illustrated in the drawings, the support members  22  are vertical and the take-up spools  24  and  26  are horizontal. In an alternative embodiment, the support members  22  are horizontal while the take-up spools  24  and  26  are vertical.  
         [0028]    In the embodiment illustrated in the drawings, the display structure  12  further comprises five idler rollers, a first idler roller  30 , a second idler roller  32 , a third idler roller  34 , a fourth idler roller  36  and a fifth idler roller  38 . Each of the idler rollers  30 ,  32 ,  34 ,  36  and  38  is disposed in parallel with the two take-up rollers  24  and  26 , and are all supported at their opposite ends by the two support members  22 . The first idler roller  30  is disposed at a first lower corner  40  of each support member  22 . The second idler roller  32  is disposed at a first upper corner  42  of each support member  22 . The third idler roller  34  is disposed at a second upper corner  44  of each support member  22 . The fourth idler roller  36  is supported at a second lower corner  46  of each support member  22 . The fifth idler roller  38  is disposed along the vertical center line of each support member  22 , several inches below the uppermost edge  48  of each support member  22 . Each of the idler rollers  30 ,  32 ,  34 ,  36  and  38  is attached to the vertical support members  22  by stationary mounting pins  50  which allow the idler rollers  30 ,  32 ,  34 ,  36  and  38  to freely rotate about their vertical axes.  
         [0029]    The idler rollers  30 ,  32 ,  34 ,  36  and  38  are adapted to support the roll of film  14  between the first take-up spool  24  and the second take-up spool  26 . The idler rollers  30 ,  32 ,  34 ,  36  and  38  are further adapted to provide for smooth scrolling of the roll of film  14  between the first take-up spool  22  and the second take-up spool  24 , and to provide at least one visual display location  52 . In the embodiment illustrated in the drawings, the roll of film  14  is disposed between the first take-up roller  24 , the first idler roller  30 , the second idler roller  32 , the third idler roller  34 , the fourth idler roller  36  and the second take-up spool  26 . The idler rollers  30 ,  32 ,  34 ,  36  and  38  provide a pair of visual display locations, a first visual display location  52   a  and a second visual display location  52   b.  The area of the display apparatus  10  between the first idler roller  30  and the second idler roller  32  defines the first visual display location  52   a,  and the area between the third idler roller  34  and the fourth idler roller  36  defines the second visual display location  52   b.  In this configuration, the film  14  is held taut between the first idler roller  30  and the second idler roller  32  to allow a still image to be easily viewed in the first visual display location  52   a.  Similarly, the roll of film  14  is held taut between the third idler roller  34  and the fourth idler roller  36  to allow a second desired still image to be easily viewed at the second visual display location  52   b.  By this configuration, two different visual images  28  can be displayed back to back within the display structure  12  at the same time.  
         [0030]    In the embodiment illustrated in the drawings, the fifth idler roller  38  is an optional idler roller, only used in special circumstances. Normally, the fifth idler roller  38  is not used at all. However, where accentuated oscillation of still images  28  at the visual display location  52  is desired, or when oversized images  28  are used, the fifth idler roller  38  can be used to provide proper oscillation. Without the use of the fifth idler roller  38 , accentuated oscillation and/or the use of elongated still images  28  could result in the undesired oscillation of a still image  28  from one of the visual display locations  52  onto the other visual display location  52 .  
         [0031]    The scroll means  16  are typically provided by at least one motor  54  for driving the first take-up spool  24  and the second take-up spool  26 , so that the roll of film  14  can be alternatively rolled forwards and backwards between the first take-up spool  24  and the second take-up spool  26 . In a typical embodiment, the at least one motor  54  is a non-servo, direct current motor. In the embodiment illustrated in the drawings, the scroll means  16  are provided by two motors, a first motor  54   a  and a second motor  54   b.  The first motor  54   a  is adapted to drive and brake the first take-up spool  24  and the second motor  54   b  is adapted to drive and brake the second take-up spool  26 . Each motor  54  is operatively attached to one of the take-up spools  24  or  26  via a drive pin  56 , and a drive belt  58  disposed between a motor pulley  60  and a take-up spool pulley  62 .  
         [0032]    Preferably, the at least one motor  54  is braked by non-mechanical dynamic braking means. By the term “dynamic braking,” it is meant using the electromagnetic force of the motor  54  to brake the rotation of the take-up spools  24  and  26 . As noted above, in the embodiment illustrated in the drawings, the first motor  54   a  drives the first take-up spool  24  and the second motor  54   b  drives the second take-up spool  26 . When it is desired to advance the roll of film  14  from the first take-up spool  24  to the second take-up spool  26 , the second motor  54   b  drives the second take-up spool  26  to wind additional film onto the second take-up spool  26 . At the beginning of this operation, the first motor  54   a  is disengaged. As the amount of additional desired film is rolled onto the second take-up spool  26 , the first motor  54   a  is engaged to provide a drag force on the first take-up spool  24 . By this dynamic braking operation, two things occur. First of all, the rotation of the second take-up spool  26  is slowed and eventually brought to a halt. Secondly, once the film  14  is brought to a halt, the film  14  is held against the idler rollers  30 ,  32 ,  34 ,  36  and  38  in a taut configuration. Holding the film  14  taut facilitates the display of desired still images  28  at the visual display locations  52 .  
         [0033]    The control means  18  operates to control the scroll means  16  to align a desired image  28  at a visual display location  52 . In the embodiment illustrated in the drawings, the control means  18  is provided by a controller  64  for controlling both the first motor  54   a  and the second motor  54   b.    
         [0034]    The controller  64  preferably comprises a central processing unit capable of accepting and responding to commands from the user and capable of storing a set of pre-programmed commands and operating criteria.  
         [0035]    In the invention, at least one image marker  66  is disposed proximate to each image  28  on the roll of film  14 , and the controller  64  further comprises a sensor  68  for identifying each image  28  on the roll of film  14  by sensing each image marker  66 . In this preferred design, the controller  64  is capable of identifying each image  28  on the roll of film  14  independent of the relative location of that image  28  on the roll of film  14 . The image markers  66  can also be used to identify the lower or upper edge of a still image  28  being displayed at the visual display location  52 , so as to allow the controller  64  to properly center the still image  28  at the visual display location  52  and so as to facilitate the proper oscillation of the still image  28  at the visual display location  52 .  
         [0036]    In a preferred design, each image marker  66  is sequentially numbered or  25  otherwise identified with respect to adjacent image markers  66 . By this design, the controller  64  can be programmed to scroll the roll of film  14  rapidly when the distance between the present location of the film  14  and a desired still image  28  is great, and to slow down the scrolling speed as the desired still image  28  is approached. In the embodiment illustrated in the drawings, one or more of the idler rollers  30 ,  32 ,  34 ,  36  and  38  has an externally protruding gear  68  which can be meshed with an engagement gear from a tachometer (not shown) operatively connected to the controller  64 . The tachometer can be used to continuously monitor the scrolling speed of the roll of film  14 .  
         [0037]    Preferably, the controller  64  further comprises a radio frequency receiver for receiving remote instruction signals regarding the operation of the display apparatus  10 . Most preferably, the controller  64  further comprises a radio frequency receiver/transmitter for both receiving remote instruction signals regarding the operation of the display apparatus  10  and for transmitting signals confirming the operation of the display apparatus  10 .  
         [0038]    It is also preferable that the controller  64  further comprise a clock which enables the controller  64  to control the scroll means to provide differerent images  28  at the visual display location  52  based upon the time of day. For example, the controller  64  can control the scroll means to advertise childrens products during daylight hours and adult products during late evenings hours.  
         [0039]    In another embodiment of the invention, the controller  64  comprises GPS information receiving means for determining the location of the display apparatus using a global positioning satellite. With this capability, the controller  64  can be programmed to display different desired images  28  at the visual display locations  52 , depending upon the physical location of the display apparatus  10 . This is an important feature for display apparatuses  10  mounted upon motor vehicles, such as taxi cabs. For example, a taxi cab operating in both English-speaking neighborhoods and Spanish-speaking neighborhoods can effectively used the display apparatus of the invention to automatically display advertising images in the appropriate language, depending upon the location of the taxi cab.  
         [0040]    In another embodiment of the invention, the controller  64  further comprises weather-sensing means for detecting weather parameters proximate to the display apparatus location. With this feature, the controller  64  can be programmed to automatically shift the emphasis of advertisements displayed at the visual display location  52  depending upon weather conditions. For example, sun block advertisements can be withdrawn in favor of umbrella advertisements as weather conditions in the location of the display apparatus  10  changes from sunny weather to rainy weather.  
         [0041]    In the embodiment illustrated in the drawings, the display apparatus  10  further comprises oscillating means  20  for oscillating the display of one of the still images  28 . The oscillating means  20  are provided by the scroll means  16  and the control means  18 . The controller  64  is preprogrammed to control the scroll means  16  to vertically oscillate a desired image  28  being displayed at both the first visual display location  52   a  and the second visual display location  52   b  by slowly scrolling the film  14  upwards and downwards while maintaining the desired images  28  within each of the two visual display locations  52   a  and  52   b.  In a typical embodiment wherein the images  28  on the roll of film  14  are about  8  inches in height, the oscillating of the images  28  is accomplished by slowly scrolling the film  14  upwards and downwards a distance of about  4  inches in each direction. Where greater oscillation is desired, the images  28  on the roll of film  14  are separated by a greater distance and the film  14  is further threaded from the second idler roller  32  under the fifth idler roller  38  before being threaded over the fourth idler roller  36  as illustrated in FIG. 7B. This provides the roll of film  14  with the additional distance necessary for extended oscillation distances.  
         [0042]    In the alternative embodiment wherein the take-up spools  24  and  26  and the idler rollers  30 ,  32 ,  34 ,  36  and  38  are disposed vertically, instead of horizontally, the oscillating means  18  is adapted to oscillate images within the visual display location  52  horizontally, instead of vertically.  
         [0043]    The oscillating means  20  can also comprise a separate oscillator  69  as illustrated in FIG. 7C. In one embodiment, the oscillator  69  is adapted to physically oscillate the entire display structure  12 . Such an oscillator  69  can be used to oscillate the visual display location  52  vertically, horizontally, diagonally or in a combination of these directions.  
         [0044]    In the embodiment illustrated in the drawings, the invention can further comprise a cover shroud  70  for enclosing the display structure  12  to insulate the sensitive components of the display apparatus  10  from wind, rain, dust, etc. The cover shroud  70  has opposed transparent sidewalls  72  which provide display windows  74  at the first and second image display locations  52 . Where appropriate, the cover shroud  70  can be attached to an undercarriage plate (not shown). In the embodiment illustrated in the drawings, the cover shroud  70  is aerodynamically shaped to minimize drag when the display apparatus  10  is installed upon a vehicle.  
         [0045]    Preferably, the display apparatus  10  further comprises a light source  76  disposed within the display structure  12  for illuminating desired images  28  at the visual display locations  52 . In the embodiment illustrated in the drawings, the light source  76  comprises two horizontally disposed light bulbs located within the display structure  12  behind both the first visual display location  52   a  and behind the second visual display location  52   b.  By this design, the light source  76  is thereby capable of “backlighting” desired images  28  at both the first visual display location  52   a  and the second visual display location  52   b,  so that the desired images  28  can be readily seen at night or in darkened indoor locations.  
         [0046]    As suggested above, the display apparatus  10  of the invention is ideal for mounting atop a vehicle, such as a motor vehicle (e.g. a taxi cab), trailer or boat.  
         [0047]    Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.