Abstract:
A camera or other device having a rechargeable battery is intended to be stored normally in a cavity of a charging-stand cradle in order to restore an electrical charge to the battery. The cradle includes a plug module that may be electrically connected to a standard alternating current (AC) outlet when the plug module is affixed to the cradle. Conversely, the plug module may be separated from the cradle to connect it to a remote AC outlet.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to a battery charging apparatus for restoring an electrical charge to a rechargeable battery, and in particular to a charging-stand cradle to be used with a battery powered camera or other battery powered device. 
     2. Description of the Prior Art 
     There is an increasing environmental concern as to how to dispose of non-reuseable batteries for cameras and other battery powered devices. Of course, rechargeable batteries, such as the known nicke-cadmium type, and plug-in battery chargers for restoring an electrical charge to a rechargeable battery have been available for a number of years. However, many users may find it a nuisance and perhaps difficult to remove a rechargeable battery from a camera or other battery powered device, to electrically connect the rechargeable battery to the battery charger, and to reinstall the recharged battery in the camera. More particularly, with a camera, many users keep the camera in a protective case when it is not in use, and therefore may neglect the charge condition of the rechargeable battery. 
     SUMMARY OF THE INVENTION 
     According to the invention, a camera or other device having a rechargeable battery is intended to be stored normally in a cavity of a charging-stand cradle in order to restore an electrical charge to the battery. The cradle includes a plug module that may be electrically connected to a standard alternating current (AC) outlet when the plug module is affixed to the cradle. Conversely, the plug module may be separated from the cradle to connect it to a remote AC outlet. 
     More particularly, the charging-stand cradle is designed to serve as an alternative to a protective case for the camera and, at the same time, restore an electrical charge to a rechargeable battery inside the camera without having to remove the battery from the camera. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a charging-stand cradle and a camera for use with the cradle, according to a preferred embodiment of the invention; 
     FIG. 2 is a perspective view similar to FIG. 1, showing how the camera is inserted into a cavity of the cradle; 
     FIG. 3 is a rear perspective view of the camera inserted in the cavity of the cradle, showing a plug module affixed to the cradle in an upright use position; 
     FIG. 4 is a perspective view similar to FIG. 3, showing the plug module affixed to the cradle in an inverted use position; 
     FIG. 5 is a perspective view similar to FIG. 3, showing the plug module removed from the cradle in a further use position; 
     FIG. 6 is a perspective view similar to FIG. 3, showing the plug module affixed to the cradle in a reversed storage position; 
     FIG. 7 is a rear perspective view of a front half of the cradle and an interior circuit board that is electrically connected via a wire lead to the plug module; 
     FIG. 8 is a circuit diagram generally of the circuit board depicted in FIG. 6; and 
     FIG. 9 is a front perspective view of the camera, showing an interior battery chamber. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to FIG. 9, a camera 1 is shown has an internal battery chamber 3 for holding a conventional rechargeable battery 5, such as the known nickel-cadmium type. A pair of internal electrical conductor tabs 7 and 9 are located in the chamber 3 for making electrical contact with respective positive and negative terminals 11 and 13 of the battery 5. A pair of external electrical conductor pins 15 and 17 accessible at one exterior side 19 of the camera 1 are connected by suitable wire leads, not shown, to the internal conductor tabs 7 and 9. 
     As shown in FIGS. 1-3 and 7, a battery charging apparatus preferably in the form of a charging-stand cradle 21 has a cavity 23 configured for receiving the camera 1 to support the camera in a battery charging position. A pair of electrical conductor pins 25 and 27 are located in respective openings 29 and 31 at the bottom of the cavity 23 for making electrical contact with the two external conductor pins 15 and 17 of the camera to restore an electrical charge to the battery 5 when the camera is supported in the cavity in the battery charging position. See FIG. 2. 
     An electrical plug module 33 has a pair of input and output prongs 35 and 37 and a ground prong 39 each configured to be inserted into a conventional alternating current (AC) outlet. See FIG. 3. The plug module 33 is connected to the two conductor pins 25 and 27 via a wire lead 41 which is soldered to a circuit board 43 that supports the two conductor pins. See FIG. 7. The wire lead 41 is long enough to permit the plug module 33 to be located remotely from the cradle 21 as in FIG. 5. 
     The cradle 21 includes a securement bracket 43, shown in FIG. 5, that includes a pair of opposite slot (only one shown) 45 for receiving respective ears 47 (only one shown) of the plug module 33 to affix the plug module removably to the cradle. This permits the plug module to be inserted into a conventional AC outlet when the plug module is affixed to the cradle 21 as in FIGS. 3 and 4 or is removed from the cradle as in FIG. 5. 
     The slots 45 of the cradle 21 and the ears 47 of the plug module 33 enable the plug module to be affixed to the cradle in respective orientations in which the ground prong 39 is located below the input and output prongs 35 and 37 as in FIG. 3 or is located above the input and output prongs as in FIG. 4. This permits the plug module 33 to be plugged into a conventional AC outlet when the plug module is affixed to the cradle 21, regardless of an upright or inverted orientation of the AC outlet. 
     The slots 45 and the ears 47 enable the plug module 33 to be affixed to the cradle 21 in a storage position in which the input, output and ground prongs 35, 37 and 39 face inwardly with respect to the cradle to project into a cavity 49 of the cradle. See FIGS. 5, 6 and 7. 
     The securement bracket 43 includes a skirted periphery 51 about which the wire lead 41 can be wrapped to store the wire lead when the plug module 33 is affixed to the cradle 21. See FIGS. 3, 4, 5 and 6. 
     A front face 53 of the cradle 21 includes three evenly spaced light-emitting diodes (LED&#39;s) 55, 57 and 59 which are electrically connected to the circuit board 43. The LED 55 when energized provides a &#34;power on&#34; indication. The LED 57 when energized provides an indication that a rechargeable battery is being charged. The LED 59 when energized provides an indication that the particular battery attempted to be charged is a non-rechargeable one, such as a known alkaline type, and therefore is the wrong battery. 
     A circuit diagram of the circuit board 43 is shown in FIG. 8. According to custom, in the circuit diagram, reference letters &#34;C&#34; indicate various capcitors, reference letters &#34;R&#34; indicate various resistors, reference letters &#34;D&#34; indicate various diodes, reference letters AMP indicate various op amps, reference letters V s  indicate a reference voltage, reference letters V batt  indicate a battery voltage, etc. In addition, a 120 volt AC to 8 volt AC reduction transformer 61 may be built into the plug module 33. As shown in FIG. 8, the circuit diagram is divided into several component sections comprising a voltage reduction section 63 which includes the reduction transformer 61, a power on indicator section 65 which includes the LED 55, a typical direct current (DC) filter section 67, a battery charging indicator section 69 which includes the LED 57, a typical wrong battery amplifier section 71, a wrong battery indicator section 73 which includes the LED 59, and a no battery inhibit section 75 which prevents the LED 59 from being energized when the camera 1 is supported in the cavity 23 of the cradle 21 but no battery is present in the camera. In operation, the reduction transformer 61 converts a 120 volt AC to a 8 volt AC when the plug module 33 is plugged into a conventional AC outlet. In turn, the 8 volt AC is half-wave rectified by the LED 55 into a direct current (DC). A resistor R1 limits the current to the battery being charged. While the battery is being charged, current passes through the resistor R1 and LED 55, causing the LED to glow to thus provide a power on indication. The 8 volt AC is also half-wave rectified by the diode D1 into a DC for the rest of the circuit sections, and capacitors C1 and C2 filter the half-wave DC to create a purer DC. A zenor diode D2 regulates the resultant voltage to 6.2 volts, to be used as a reference voltage V s . The actual voltage V batt  from the battery being charged and a reduced reference voltage determined by the reference voltage V s  and two resistors R6 and R7 are fed into an op amp AMP 1. When the voltage V batt  from the battery is less than the reduced reference voltage, the LED 57 glows to thus provide a charging indication. Conversely, when the voltage V batt  from the battery is greater than the reduced reference voltage, the LED 57 no longer glows to thus provide a full charge indication. If the battery is a non-rechargeable one, the actual voltage V batt  from the battery is different than in the case of a rechargeable one, and the resistors R10, R11 and R12, the capcitor C6, and the op amp AMP 3 compare the difference as amplified by the op amp AMP 2 to another reduced reference voltage determined by the voltage V S  and the resistors R10 and R11. When the other reduced reference voltage is less than the amplified voltage, the LED 59 flashes to thus provide a wrong battery indication. If no battery is present, the LED 59 is prevented from flashing by the resistors R13, R14, R15, and R16 and the op amp AMP 4. 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected within the ordinary skill of the art without departing from the scope of the invention.