Abstract:
Harmful effects of the sun are becoming more prominent than they have been in the past. Thus, appropriately shielding ourselves from the sun has become ever more important. Unfortunately, applying sunscreens to infants may not be preferable thus sunshade umbrellas have been developed that clamp onto a stroller and are user positionable to provide shade to the infant located thereunder. Unfortunately, as the stroller I moved with respect to the sun, the orientation of the umbrella must be varied in order to ensure the infant is in adequate shade. Not applicable to just stroller umbrellas, an automated position in system for an umbrella is thus disclosed. The automated positioning system orients the canopy of the umbrella in relation to the sun so that shade at a predetermine location is provided thereunder.

Description:
[0001]     This application is a continuation in part of U.S. patent application Ser. No. 10/338,867, filed on: Jan. 9, 2003. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to the area of solar protection coverings and more specifically to the area of automated canopies that provide solar protection.  
       BACKGROUND OF THE INVENTION  
       [0003]     Skin cancer has become an increased concern due to the depletion of the ozone layer, which protects people from the sun&#39;s harmful UV rays. Thus, in order to provide protection from the sun, people now use umbrellas not only to keep themselves dry from rain but also to provide shade from the harmful effects of the sun. Solar umbrellas for providing shade are quite prevalent on patios and other outdoor facilities.  
         [0004]     Of course, sunscreens can optionally be applied by individuals to block the harmful UV rays, however in some cases this may not be a preferable option, especially when very young infants or those with allergies are involved. Since the chemicals in the sunscreens may react adversely with the skin of young infants or those with allergies. Young infants are especially susceptible to harmful UV rays when they are pushed around in a stroller by their parents. Thus, the strollers are typically equipped with sun shades that are spatially oriented by parents in such a manner to provide sun protection to the infant.  
         [0005]     Unfortunately, as the stroller is moved, the spatial orientation of a sun shade must typically be varied in order to maintain shade on the infant. Thus, as the stroller is wheeled around the position of the shade on the infant changes; and as a result the parents have to stop pushing the stroller and they have to reposition the sun shade in order to maintain their infant in the shade cast by the sun shade.  
         [0006]     A need therefore exists for providing an umbrella, which offers solar protection in a shadow cast therefrom, and one that does not require constant manual repositioning as a result of the orientation of the sun changing with respect to the canopy. It is therefore an object of the invention to provide an automated positioning system for a canopy of an umbrella that varies its position in an automated manner to facilitate providing of a shaded area at a predetermined location as the orientation of the sun varies with respect to the canopy.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with the invention there is provided a method of spatially orienting a canopy comprising the steps of: detecting an orientation of a light source relative to the canopy;  
         [0008]     moving of the canopy in dependence upon the detected orientation, the canopy positioned for providing a shade under the canopy; and, maintaining the shade about an approximately predetermined location relative to which the canopy is moved.  
         [0009]     In accordance with the invention there is also provided an apparatus comprising: a canopy having an upper surface and a lower surface for providing shade to a shaded area opposing the lower surface in response to light impacting the upper surface; a first photodetector for detecting at least one of an amount of light in the shaded area and an amount of light impacting the canopy upper surface, the detector for generating a photocurrent in response to light incident thereon;  
         [0010]     a control circuit for receiving the photocurrent and for generating a first control signal in dependence thereon; a positioning mechanism having a fixed portion and having a moving portion coupled with the canopy for spatially orienting the canopy relative to the fixed portion about at least an axis in response to the control signal for, in use, maintaining at least a portion of the shaded area in an approximately predetermined spatial orientation relative to the fixed portion. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Exemplary embodiments of the invention will now be described in conjunction with the following drawings, in which:  
         [0012]      FIG. 1  illustrates a prior art solar umbrella;  
         [0013]      FIG. 2   a  illustrates a prior art variation of a solar umbrella;  
         [0014]      FIG. 2   b  illustrates a resilient portion provided with the prior art umbrella shown in  FIG. 2   a;    
         [0015]      FIG. 3  illustrates a circuit for use with an embodiment of the invention;  
         [0016]      FIG. 4  illustrates a variation of a circuit for use with an embodiment of the invention;  
         [0017]      FIG. 5  illustrates an embodiment of the invention;  
         [0018]      FIG. 6  illustrates a positional change of a canopy from an initial position shown in  FIG. 5  to a new position when the canopy is provided with sunlight;  
         [0019]      FIG. 7   a  illustrates a spatial orientation of photodetectors on a canopy;  
         [0020]      FIG. 7   b  illustrates an orientation of a single photodetector on a canopy;  
         [0021]      FIG. 8  illustrates a dual axis pivot component;  
         [0022]      FIG. 9  illustrates a variation of the dual axis pivot component shown in  FIG. 8 ;  
         [0023]      FIG. 10  illustrates a stroller equipped with an automated canopy positioning system; and,  
         [0024]      FIG. 11  illustrates an umbrella having a variation of the dual axis pivot component shown in  FIG. 9 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     In  FIG. 1   a,  a prior art solar umbrella  10  is shown. The umbrella  10  includes a canopy  11 , for providing shade from the sun, an umbrella shaft  12 , and a mechanism (not shown) for allowing movement of the canopy between an open and a closed position. In the open position the canopy provides shade from the sun, and in the closed position the canopy other than substantially provides shade from the sun. The umbrella shaft  12  is coupled to a resilient portion  16 , which is further coupled to a mounting portion  14  for rigidly mounting to a frame member  13 , through the use of a clamping mechanism (not shown). The frame member  13  forms part of a stroller (not shown). The resilient portion  16  is of a type that facilitates maintaining of the spatial orientation of the umbrella shaft  12  with respect to the mounting portion  14  in response to a force applied to the umbrella shaft, where the force is sufficient to overcome the resiliency of the resilient portion  16 . Thus, the resilient portion  16  is movable or malleable to set the spatial orientation of the canopy  11  and to maintain the spatial orientation of the canopy  11  with respect to the frame member  13  during normal use.  
         [0026]     For instance, when the wind blows the resilient portion  16  allows for some movement of the canopy  11  with respect to the frame member  13  as a result thereof. However, it approximately maintains the spatial orientation of the canopy  11  with respect to the frame member  13 , unless a sufficient force is applied to the umbrella shaft  12  to overcome the resiliency in order to re orient the canopy  11  with respect to the frame member  13 . Thus, when the clamping mechanism (not shown) is fixedly mounted to the frame member  13  as part of a stroller, the umbrella shaft  12  is manually repositioned in such a manner that the canopy  11  provides shade to a shaded area in which, for instance, an infant is seated in the stroller.  
         [0027]     Effectively, the canopy blocks a portion of the harmful UV rays impacting on the shaded area. Unfortunately, as the orientation of the stroller changes with respect to the sun, the spatial orientation of the canopy  11  must be manually varied in order to re-orient the canopy  11 , such that the shaded area remains shaded.  
         [0028]     Prior art  FIG. 2   a  illustrates a variation of a solar umbrella  20 . The umbrella  20  has a canopy  21  and an umbrella shaft  22 . The umbrella shaft  22  is coupled to a moving portion (not shown) of a pivot component  26  having a moving portion and a fixed portion  24 . The fixed portion of the pivot component  26  is for rigidly mounting to a frame member  23  in the form of part of a stroller (not shown). The pivot component is a single axis pivot component  26 , of a design for facilitating movement of the umbrella shaft  22  with respect to the fixed portion  24  about a single axis. The pivot allows for vaying the spatial orientation of the canopy  21  with respect to the frame member  23  in response to loosening of a nut  27 , releasably engaged on a thread. The nut is for selectively frictionally engaging the moving portion with respect to the fixed portion  24  of the pivot component  26 . Thus, by loosening of the nut  27 , the canopy  21  is manually variably spatially orientable with respect to the fixed portion  24  in a spatial orientation about the single axis. Afterwards the nut  27  is tightened to fix the spatial orientation of the canopy  21  with respect to the fixed portion  24 .  
         [0029]     In accordance with prior art  FIG. 2   b,  shown is a solar umbrella  200 , a resilient portion  260  is provided between the umbrella shaft  22  and the pivot component  26  in order to facilitate movement of the canopy  21  in response to external forces such as wind, as well as to facilitate spatial orientation of the canopy. The resilience is selected to maintain the canopy  21  with respect to the fixed portion  24  about at least one axis.  
         [0030]     Unfortunately, as the stroller is moved with respect to the sun, periodic variations in the spatial orientation of the canopy  11  and  21  must be manually performed in order to ensure that the shaded area thereby provided encompasses the infant. Furthermore, if the solar umbrella is for instance used to provide shade to a fixed object in the form of a table, then movement of the sun with respect to the table also causes the shaded area under the canopy to vary in position relative to the fixed object and thus manual reorienting of the canopy is necessary to ensure that the shaded area under the canopy is at a desirable spatial orientation.  
         [0031]      FIG. 3  illustrates a circuit for use with an embodiment of the invention. The circuit uses a first photodetector  31  to receive light and to generate a photocurrent in response thereto. The photocurrent generated by the photodetectors is received by a control circuit  33 , which is further coupled to an actuator  34 . The control circuit comprises circuitry which determines, from the received photocurrent, a magnitude of light energy impacting on the surface of the photodetector  31 . In dependence on the magnitude of the light energy, a control signal is generated by the control circuit. The control signal is provided to the actuator, wherein the control signal has at least a polarity and preferably is also characterized by a magnitude.  
         [0032]      FIG. 4  illustrates a variation of the circuit for use with an embodiment of the invention. The circuit uses first and second photodetectors  48  and  49  to receive light, the first and second photodetectors  48  and  49  for generating photocurrents in response thereto. Both photocurrents, provided by the photodetectors, are received by a control circuit  43 , which is further coupled to an actuator  44 . The control circuit  43  comprises circuitry that determines from the received photocurrents a relative magnitude of light energy impacting on the surface of each of the photodetectors  43 ,  44 . In dependence upon the relative magnitude of the light energy, a control signal is generated and provided to the actuator  44 . The control signal has at least a polarity and preferably also has a variable magnitude. Thus when the first photodetector  48  receives more light energy than the second photodetector  49  the control signal has a first polarity, and when the first photodetector  48  receives less light energy than the second photodetector  49  the control signal has a second other polarity. The first and second polarities each in response thereto result in the actuator  44  moving in different directions being a first direction and a second other direction, respectively.  
         [0033]     Optionally, the circuit is solar powered using at least a solar cell  47 . As is evident to those of skill in the art, since the canopy is for use in providing shade, sun energy is typically incident on an upper surface of the canopy during use and, as such, placement of solar cells is straightforward. The control circuit additionally has a circuit that stores electrical energy received from the solar cell in an energy storage medium in the form of a capacitor or a rechargeable battery. Further optionally, the photodetectors act as solar cells and photocurrent therefrom is used to charge an energy storage circuit that is then used to power movement of the actuator in either the first direction or the second other direction.  
         [0034]     In  FIG. 5 , an embodiment of the invention is shown that utilizes the circuit featured in  FIG. 4 . In this embodiment an umbrella is provided, the umbrella has a canopy  51  and an umbrella shaft  52 . The umbrella shaft  52  is coupled to a moving portion  501  of a pivot component  56  having the moving portion  501  and a fixed portion  54 . The moving portion  501  is disposed proximate an end of the umbrella shaft opposite the canopy  51 . The fixed portion  54  of the pivot component  56  is for rigid mounting to a frame member  53 . The frame member  53  is for example part of a vehicle, preferably in the form of a stroller (not shown) or part of a stationary object, such as a table. Of course, the rigid mounting may be other than rigidly coupled to the frame member  53 .  
         [0035]     The circuit assembly has first and second photodetectors  58  and  59 , preferably disposed about an outer surface of the canopy  51 , electrically coupled to a control circuit  57  for providing a control signal to an actuator  55 . Thus in response to a control signal generated by the control circuit  57 , the canopy  51  is spatially oriented about a first axis with respect to the fixed portion  54  by the actuator  55 . The pivot component is preferably at least a single axis pivot component  56  for supporting actuated movement of the umbrella shaft  52  with respect to the fixed portion  54  about at least a single axis with the actuator  55  and circuit assembly as shown in  FIG. 4 . Movement about the at least a single axis results in the canopy sweeping out a first arc when the canopy moving portion  501  pivots about the first axis of the pivot component  56 . Alternatively, the first and second photodetectors  58  and  59  are mounted about an other than outer surface of the canopy in such a manner that other than light impacting the outer surface of the canopy is received thereby. Alternatively, at least one of the first and second photodetectors  58  and  59  is mounted below the canopy adjacent a window therein for allowing light to pass therethrough.  
         [0036]     For example, in a first predetermined mode of operation, the control circuit  57  samples photocurrents provided from the first and second photodetectors  58  and  59 . The control circuit  57  determines relative amplitude between the photocurrents and in response to the determined relative amplitude provides a control circuit for causing the actuator  55  to move the canopy  51  in the direction toward the photodetector providing more photocurrent, until a point is reached wherein the amplitude of the photocurrents generated by each of the photodetectors is approximately equal. Thus, in the first mode of operation, the canopy  51  is spatially oriented in first and second directions in an attempt to equalize the photocurrents generated by each of the photodetectors. Alternatively, different photodetector placement and control criteria are implemented within the control circuit  57  to, for example, position the canopy  51  in such a manner as to detect a least amount of photocurrent.  
         [0037]     Thus, when the apparatus shown in  FIG. 5  is mounted to a moving vehicle frame member  53  using a clamping mechanism as part of the fixed portion  54 , movement of the vehicle with respect to the sun, or other light source, results in automated movement of the canopy  51  with respect to the fixed portion  54  in response to the control signal from the control circuit  57 . One of skill in the art will understand that the movement described above is in response to the control circuit satisfying a design goal of equalizing photocurrents generated by each of the photodetectors.  
         [0038]     Alternatively, another design goal is implemented when the photodetectors are different or differently oriented relative to the canopy. Referring to  FIG. 6 , the sun  601 , or other light source, provides light that is incident on both photodetectors  58  and  59 . Using an initial position as shown in  FIG. 5 , the control circuit  57  receives both photocurrents and generates a control signal having such a polarity that the actuator  55  automatically re-positions the canopy  51 , with respect to the fixed portion  54 , in such a manner that the canopy automatically arrives at an other than initial position. In this other than initial position shade from the light source is provided under the canopy between shade lines  602  and  603 , as shown in  FIG. 6 . In this other than initial position, each of the photodetectors are illuminated by substantially a same amount of light and movement of the canopy  51  with respect to the fixed portion  54  is approximately stopped. In this approximately stopped position, the control circuit  57  either generates a control signal that changes polarities at a rate that is insufficient to cause substantial displacement of the actuator  55  in either the first or second directions, or the magnitude of the control signal is decreased sufficiently to provide other than sufficient power to move the actuator  55  substantially as the difference in photocurrents observed on each of the photodetectors is approximately zero. Of course, the difference in photocurrents observed on each of the photodetectors is optionally in accordance with other predetermined design goals of the control circuit.  
         [0039]     Referring to  FIG. 7   a,  the orientation of a first pair of photodetectors  58 ,  59 , and a second pair of photodetectors  78 ,  79  are shown. The first pair of photodetectors  58  and  59  are for generating photocurrents that are for use by the control circuit to provide a control signal for positioning the canopy  70  about a first axis and the second pair of photodetectors  58  and  59  are for generating photocurrents that are for use by the control circuit to provide a control signal for positioning the canopy  70  about a second axis. Preferably the first and the second axes are orthogonal one to the other.  
         [0040]     In  FIG. 8 , a dual axis pivot component  86  is shown, mounted to a fixed portion  84  that is mounted to a frame  83  of an object. An umbrella shaft  82  is pivotally mounted to the dual axis pivot component  86 . The dual axis pivot component comprises actuators; the actuator are for pivoting the canopy  70  about a first axis  801  and a second axis  802 , with respect to the fixed portion  84 . Preferably, the photodetectors shown in  FIG. 7   a  are oriented on the canopy  70  in such a manner that the first pair of photodetectors, photodetectors  88   a  and  88   b,  are positioned substantially parallel to an arc swept by the umbrella shaft when the umbrella shaft moves about the first axis  801  and that the second pair of photodetectors, photodetector  89   b  and another photodetector (not shown), are positioned substantially parallel to an arc swept by the umbrella shaft when the umbrella shaft moves about the second axis  802 .  
         [0041]     Thus, the umbrella shaft  82  moves about the two orthogonal axes  801  and  802  in response to first and second control signals generated by the control circuit (not shown). The control circuit shown in  FIG. 4  is optionally employed and provided with an additional two photodetectors and an additional actuator in order to facilitate movement of the umbrella shaft about the two axes. When the canopy  70  is provided with light from a light source, such as the sun, the first and second control signals provided to first and second actuators, respectively, result in the canopy  70  of the umbrella automatically orienting itself toward the sun in a manner in accordance with predetermined design goals. Preferably, the shaded area under the canopy provides shade in a desired location as a result of the spatial orienting of the canopy  70  with respect to the fixed portion  84 . Alternatively, a single actuator is provided for orienting the canopy about both axes in response to the two control signals.  
         [0042]     Of course, instead of using the circuit shown in  FIG. 4 , optionally the circuit shown in  FIG. 3  is utilized with the embodiment shown in  FIG. 8 . When using the control circuit shown in  FIG. 3 , a single photodetector  72  is provided on the canopy  71  or umbrella shaft (not shown). In this case however, when a single photodetector is used, as shown in  FIG. 7   b,  it is more difficult to determine in which direction to actuate either of the actuators. As a result, for a single axis, the control circuit stores the photocurrent generated by the photodetector  72  in a current orientation of the canopy  70 , orients the canopy in a first direction, stores the photocurrent generated by the photodetector  72  in this new orientation, then determines whether the stored photocurrent is larger for the orientation of the canopy in the current orientation or the new orientation, and generates a control signal provided to the actuator to position the canopy in such a manner so that the photocurrent generated by the photodetector  72  is in accordance with predetermined parameters set forth within the control circuit. For a dual axis system, this same process is repeated for pivoting of the canopy  70  about the second axis  802 . However, using a single photodetector is less preferable than using two photodetectors per axis. When two photodetectors are employed for each axis, an immediate gradient is observed for that axis by measuring a difference in the magnitudes of each of the photocurrents within the control circuit.  
         [0043]     Referring to  FIG. 9 , a variation of the dual axis pivot mechanism is shown for a solar umbrella for use with a table  908 . A dual axis pivot component is provided between a fixed portion  903  and an umbrella shaft  905 . The fixed portion  903  is mounted to the table  908 . The dual axis pivot component has an intermediate component  904 , thus the umbrella shaft  90  is pivotally mounted to the intermediate component  904 , for pivoting about a first axis  906  with respect to the intermediate component  904 , and the intermediate component  904  is pivotally mounted to the fixed portion  903  for pivoting about a second axis  907  with respect to the fixed portion  903 . Preferably, the first and the second axes  906  and  907  are orthogonal. At an end of the umbrella shaft  905 , other than the end that is pivotally mounted to the intermediate component  904 , a canopy  70  is disposed. The umbrella shaft  905  has a mechanism for allowing movement of the canopy  70  between an open position and a closed position.  
         [0044]     Two actuators (not shown) are provided for pivoting of the canopy  70  about the first axis  906  and the second axis  907  in response to photocurrents generated by photodetectors  98   a  and  98   b  (hidden in  FIG. 9 ), and photodetectors  99   a  (hidden in  FIG. 9 ) and  99   b  and photodetectors  58  and  79  (hidden in  FIG. 8 ). Preferably the photodetectors such as those shown in  FIG. 7   a  are oriented on the canopy  70  in such a manner that the first pair, photodetectors  98   a  and  98   b,  are positioned substantially parallel to an arc swept by the umbrella shaft when the umbrella shaft pivots about the first axis  906  and that the second pair, photodetector  99   b  and another photodetector (not shown), are positioned substantially parallel to an arc swept by the umbrella shaft when the umbrella shaft pivots about the second axis  907 . A control circuit (not shown) is provided for receiving the photocurrents from each of the photodetectors and for generating the control signal for provision to the actuators. Thus, in use, the actuators automatically orient the canopy  70  with respect to the table  908  in accordance with predetermined criteria set forth within the control circuit. The canopy  70  provides shade within a shaded area between shadow lines  901  and  902 .  
         [0045]     Preferably, the shaded area varies its position with respect to the canopy as the orientation of the table with respect to the sun is varied thus providing shade to the table at a similar location as the orientation of the table to the sun changes.  
         [0046]     Referring to  FIG. 10 , a further embodiment of the invention is shown. In this embodiment a stroller  1002  is provided with a canopy  1001  pivotally mounted to a frame portion  1009  of the stroller about pivot points  1005  and  1006 . The canopy  1001  exhibits actuated movement with respect to the stroller  1002  between first and second positions  1003  and  1004 , respectively. Photodetectors  1007  and  1008  are disposed on at least one of a frame portion of the stroller and on the canopy to detect light and to generate photocurrent in response thereto. A control circuit (such as the one illustrated in  FIG. 4 ) is used to receive this photocurrent and to provide a control signal for actuating movement of the canopy. For powering of the control circuit an optional generator  1010  is installed with its stator coupled to the frame portion  1009  and its armature coupled to a wheel on the stroller. Thus, movement of the stroller results in rotation of the armature, which in turn provides electrical energy to the control circuit. Optionally, an energy storage device in the form of a battery is provided for storing energy and for powering of the control circuit and actuator when the stroller is stationary.  
         [0047]     Referring to  FIG. 1 , a further embodiment of the invention is shown. In accordance with this embodiment, a variation of the dual axis pivot mechanism is shown for a solar umbrella for use with a table  1108 . In this case a dual axis pivot component is provided between a fixed portion  1103  and an umbrella shaft  1105 . The fixed portion  1103  is mounted to the table  1108 . The dual axis pivot component has an intermediate component  1104 , thus the umbrella shaft  1105  is pivotally mounted to the intermediate component  1104 , for pivoting about a first axis  1106  with respect to the intermediate component  1104 , and the intermediate component  1104  is pivotally mounted to the fixed portion  1103  for pivoting about a second axis  1107  with respect to the fixed portion  1103 . Preferably, the first and the second axes  1106  and  1107  are orthogonal. At an end of the umbrella shaft  1105 , other than the end that is pivotally mounted to the intermediate component  1104 , a canopy  70  is disposed. The umbrella shaft  1105  preferably includes a mechanism for allowing movement of the canopy  70  between an open position and a closed position. Two actuators (not shown) are provided for pivoting of the canopy  70  about the first axis  1106  and the second axis  1107  in response to photocurrents generated by photodetectors  78  and  59 , and photodetectors  58  and  79  (occluded in  FIG. 11 ).  
         [0048]     Alternatively, the canopy includes a switch actuated by opening and closing of the canopy. Thus in a first open position the switch is actuated and electrical energy from a power source is provided to the control circuit. In a second closed position electrical energy from the power source is other than provided to the control circuit.  
         [0049]     Alternatively, a rain sensor  1112 , and a rain detection circuit  1114 , is provided for detecting whether the upper surface of the canopy is subjected to rain. If a determination is made that rain is present then the rain sensor provides a rain signal to the control circuit. The control circuit in response to the rain signal provides control signals for moving the canopy to a covering position. For an umbrella type canopy, this is an upright position for the support shaft.  
         [0050]     Of course, the optical sensors need not be disposed on the umbrella canopy. Optionally they are disposed on other than the canopy of the umbrella in such an orientation that they detect one of shade within the shaded area formed by the canopy and an angle of light impacting the canopy. Thus, moving of the canopy need not result in motion of the photodetectors.  
         [0051]     Advantageously, by providing an automated system for positioning of the canopy with respect to an object, manually orienting of the canopy is for the most part obviated.  
         [0052]     Preferably, the control circuit is powered by solar power or stroller motion, obviating the need for extension cords and batteries. Further, this results in an environmentally friendly automated canopy positioning system. Alternatively, the positioning system is powered by a portable power source in the form of a battery. Further alternatively, the positioning system is powered by a power grid.  
         [0053]     Numerous other embodiments may be envisaged without departing from the spirit or scope of the invention.