in fig1 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 . 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 . 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 . prior art fig2 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 . in accordance with prior art fig2 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 . 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 . fig3 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 . fig4 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 . 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 . in fig5 , an embodiment of the invention is shown that utilizes the circuit featured in fig4 . 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 . 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 fig4 . 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 . 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 . thus , when the apparatus shown in fig5 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 . alternatively , another design goal is implemented when the photodetectors are different or differently oriented relative to the canopy . referring to fig6 , 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 fig5 , 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 fig6 . 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 . referring to fig7 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 . in fig8 , 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 fig7 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 . 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 fig4 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 . of course , instead of using the circuit shown in fig4 , optionally the circuit shown in fig3 is utilized with the embodiment shown in fig8 . when using the control circuit shown in fig3 , 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 fig7 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 . referring to fig9 , 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 . 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 fig9 ), and photodetectors 99 a ( hidden in fig9 ) and 99 b and photodetectors 58 and 79 ( hidden in fig8 ). preferably the photodetectors such as those shown in fig7 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 . 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 . referring to fig1 , 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 fig4 ) 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 arniature , which in turn provides electrical energy to the control circuit . optionally , an energy storage device 1014 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 . further optionally , an electrical port 1012 having a predetermined configuration consistent with an interface for a portable electronic device is provided . for instance , the electrical port 1012 receives power from the energy storage device 1014 . referring to fig1 , 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 fig1 ). 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 . 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 . 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 . 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 . 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 . numerous other embodiments may be envisaged without departing from the spirit or scope of the invention .
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 .