Abstract:
An improved apparatus for charging a cell phone battery in the dark. An LED and its control circuitry including a control switch are included in a USB connector to automatically illuminate a cell phone and its charging port or receptacle or jack, which happen to be located in an unlit or pitch black space, when a user attempts to insert a USB connector plug into the charging port for purposes of charging the battery. The LED is automatically energized by the user&#39;s mere touching of the overmold of the USB connector at its flat or bottom side, without otherwise manually operating the control switch, and thereby eliminating hunting in the dark for a control switch on the USB connector. This apparatus is useful with both standard charging equipment and with dongle charging equipment.

Description:
BACKGROUND 
       [0001]    Cell phones are commonplace today with hundreds of millions of cell phone users around the globe. A cell phone (cellular phone or mobile phone), being a mobile device, requires a battery in the cell phone chassis to power the phone. This battery needs to be recharged regularly, if not daily by connecting it to a power source. One frustrating aspect of charging this battery in complete darkness, e.g., when in an unlit room or other dark space, is to conveniently illuminate the relevant space and thereby locate the charging receptacle or port, typically a micro USB jack, on the cell phone chassis and to properly orient the charging plug relative to the jack. Applicant hereby provides a convenient and novel solution to this problem. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]      FIG. 1A  is a perspective diagram of an exemplary embodiment of a connector plug which includes apparatus related to the present invention; 
           [0003]      FIG. 1B  is a side view of the exemplary embodiment of  FIG. 1A ; 
           [0004]      FIG. 1C  is a front view of the exemplary embodiment of  FIG. 1A ; 
           [0005]      FIG. 2  is a functional block diagram including the exemplary connector plug embodiment of  FIG. 1  in relationship to a power source and a cell phone (battery) to be charged; 
           [0006]      FIG. 3  is another functional block diagram showing more detail of the connector plug embodiment of  FIG. 2 ; 
           [0007]      FIG. 4  is a circuit schematic diagram of an exemplary circuit that may be used in and/or with one or more functional blocks of  FIG. 3 ; and 
           [0008]      FIG. 5  is a timing, chart showing the timing of the operation of the circuitry of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0009]    In this description, the same reference numeral in different Figs. refers to the same entity. Otherwise, reference numerals of each Fig. start with the same number as the number of that Fig. For example,  FIG. 3  has numerals in the “ 300 ” category and.  FIG. 4  has numerals in the “ 400 ” category, etc. 
         [0010]    In overview, embodiments of the present invention include connector apparatus, such as a universal serial bus (USB bus) connector plug, typically a micro USB connector plug, holding a light emitting diode (LED). The LED is supported by, and oriented in, the connector plug in a manner to allow the LED to shine light on the connector plug mate located on a cell phone, and this is very useful when in the dark or in pitch blackness. The light shines when a user merely touches the over-mold of the connector. The user then brings the connector in close proximity to the connector mate to illuminate it. This embodiment is particularly useful for making the connection to recharge the cellular telephone&#39;s rechargeable battery, through a micro USB port on the cell phone, by way of a USB bus, when in the dark, because the LED light illuminates both the cell phone and its connector mate, not to mention the immediate environment as well. This allows the user to easily make the connection between connector plug and connector jack in the dark. The bus, at the end opposite to that of the connector is conductively connected, either directly or through another connector plug/jack combination, to an electric power source. Two wires in the bus are dedicated to carrying electric power from that power source to the LED. 
         [0011]    In applications other than only re-charging a battery, the bus can include other wires, isolated and insulated from the power wires, for carrying data, packets, etc. The connector and its mate are configured to pass-through the data and/or packets from their source to their destination on conductive paths insulated and isolated from the LED power paths. And in another application, unrelated to charging a cell phone, the above-noted another connector plug/jack combination can include another control switch to operate the LED from the opposite end of the bus, the end next to the power source, discussed further below. 
         [0012]    In a particular embodiment, a connector plug (plug) is affixed to one end of a cable, the plug having a flat or bottom side and a front face for mating with a connector-mate (jack). There are electrical contacts protruding from the front face of the plug. There is an LED supported by the plug and recessed into the front face to allow light emitted from the LED to illuminate the jack when being connected, while not interfering with the front thee. There is a source of electric power applied to the other end of the cable, the power being carried by two dedicated wires in the cable to terminals on the LED, thereby energizing the LED and allowing it to emit light, under control of a user. A switch is included within the plug, the switch automatically closing when the user merely touches the flat or bottom side of the plug, without otherwise manually operating, the switch. The LED light illuminates the jack when the switch is closed and when the plug is being mated with the jack by the user. Typically, the plug is as micro USB plug and the jack is a micro USB jack. 
         [0013]      FIG. 1A  is a perspective diagram of an exemplary embodiment of a connector plug related to the present invention. In  FIG. 1A , connector  100  is a micro USB plug depicted in perspective and shows over-mold  101  supporting electrical contacts  102  that protrude from front face  105 . Over-mold  101  contains LED  103  which is oriented so that its light, when energized, shines directly ahead relative to from face  105 , in the direction pointed-to by contacts  102 . Cable  104  is connected from connector  100  to a source knot shown) of electric power. 
         [0014]      FIG. 1B  shows a side view of connector  100 , and it is seen that a portion of the front face is angled to permit proper interfacing or mating with a complementarily-angled front face on the connector mate (not shown). In a particular embodiment, that angle can be approximately twenty-five degrees, as shown. 
         [0015]      FIG. 1C  is a front view of the exemplary embodiment of  FIG. 1A . Flat or bottom surface  106  of over-mold  101  of micro USB plug  100  is identified. LED  103  is shown positioned above contacts  102 . 
         [0016]      FIG. 2  is a functional block diagram including the exemplary connector plug embodiment of  FIG. 1  connected from a power source and depicting a cell phone battery which may be charged thereby. At the left-hand side of the drawing, cell phone  201  includes its rechargeable battery  206 . Battery  206  is conductively connected to cell phone circuitry (not shown) and to battery-charging electrical contacts  202  of connector-mate or micro USB jack  207 . Contacts  202  are configured to receive, and make good electrical contact with,  102  supported by connector plug  100 . Slanted face  203  on connector-mate  207  dovetails with angled face  204  on connector plug  100  to allow a complementary interfacing there-between. LED  103  is powered by dedicated conductive wiring (not shown) located in cable  104  and connected to power source  205 , which is a DC source of electrical power. Power source  205  can be a DC source derived from AC power, such as that obtained from ordinary household 120 volt, 60 cycle power or, alternatively, can be a portable DC battery which is used with a dongle for purposes of charging a cell phone, in which case cable  104  would be a dongle. 
         [0017]      FIG. 3  is another functional block diagram showing more detail of the connector plug embodiment of  FIG. 2 . Over-mold  101  is shown containing LED  103  and variable capacitance switch  301 . Switch  301  is arranged to control LED  103 . Switch  301  is connected from power source  205  via cable  104  and, depending on the state of the switch, either permits, or doesn&#39;t permit, power from power source  205  to be applied to LED  103 . When power is applied to the LED it emits light; when power is not applied to the LED it doesn&#39;t emit light. LED  103  can be a commercially available white light LED which is powered by levels of voltage and current that are typical of those needed for powering a commercially available LED. 
         [0018]      FIG. 4  includes an exemplary electrical circuit that ma be used to implement the variable capacitance switch  301  of  FIG. 3 . Voltage V+ is derived from power source  205 , is a constant voltage, and is applied across variable and touch-sensitive capacitor  401  and resistors  402  and  403  to ground. Junction  404  is conductively connected to the input of inverter  406  and also to the anode of diode  410 . The output of inverter  406  is applied to the anode of diode  409 . The cathodes of diodes  409  and  410  are conductively connected to each other and to one end of resistor  412 , the other end of resistor  412  being connected to the control input of bistable multi vibrator  414 . 
         [0019]    In operation, before a user touches the flat or bottom portion of overmold  101  of the micro USB plug  100 , capacitance  401  is at a quiescent or fixed or default capacitance value wherefore current flow from constant de voltage source V+ to ground via resistors  402  and  403  is zero and remains zero while capacitance  401  is in this default capacitance value state. In this state all voltage from V+ is impressed across capacitor  401 . However, when a user touches the bottom, or flat side, of overmold  101 , as the user would do when attempting to connect electrical contacts  102  to electrical contacts  202 , capacitor  401  suddenly changes its capacitance value, and this causes LED  103  to be energized and emit light. 
         [0020]    The equation for electrical charge on a capacitor is Q=CV, where Q is charge, C is capacitance and V is voltage. Since electrical current is the flow of electrical charge, or the time rate of change of electrical charge, one can derive an equation for current from this charge equation using differential calculus by differentiating both sides which gives I=dQ/dt C(dVidt)+V(dC/dt). Because voltage V+ is constant in this embodiment, (dV/dt) is zero. But, when the capacitance value C changes, the quantity (dC/dt) is non-zero wherefore current I changes from zero to some non-zero value. 
         [0021]    If touch-sensitive capacitor  401  is configured so that touching the bottom side of overmold  101  increases its capacitance value, then (dC/dt) is a momentary positive change, wherefore the change in current is from zero o a positive current flow from V+ to ground. Conversely, when the user lets go of the overmold, removing that touching decreases capacitance value of capacitor  401  from that previously increased value back down to the default capacitance value, and (dC/dt) is a momentary negative value, wherefore the change in current is from zero to a negative current flow from ground to V+. 
         [0022]    Under the opposite condition, if touching the bottom side of overmold decreases capacitance value of capacitor  401 , then opposite capacitance changes from those described above with opposite momentary current flows from those described above would be experienced. 
         [0023]    Current shall flow when the capacitance value changes and not when the capacitance value is constant at either the default quiescent value (untouched overmold) or at the changed quiescent value (touched overmold). This current dynamic is illustrated in  FIG. 4 . Waveform  405  represents current flow from V+ to ground and, by voltage divider action of resistors  402  and  403 , also represents voltage at node  404 . Current flows from V+ to ground when the flat bottom side of overmold  101  is touched by the user (provided that capacitance of capacitor  401  is thereby increased) at a time coincident with pulse  405   a.  Current flows in the reverse direction from around to V+ when overmold  101  is dropped by the user (wherefore capacitance of capacitor  401  is thereby decreased) at a time coincident with pulse  405   b.  Waveform  405   a  results from a positive capacitance change and is shown as a positive current flow from V+ to ground or as a positive voltage at node  404 ; waveform  405   b  results from a negative capacitance change (back to default quiescent value) and is shown as a negative current flow from ground to V+ or as a negative voltage at node  404 . 
         [0024]    Because of voltage divider action of resistors  402  and  403 , waveform  405 , as noted above, also represents voltage at node  404  which is the voltage input to inverter  406  and to the anode of diode  410 . (Waveforms  405  and  411  are essentially identical.) Waveform  408 , which is the output from inverter  406 , is the inverse of its input and is, therefore, the inverse of waveform  411 . 
         [0025]    At the time when positive voltage represented by pulse  411   a  is applied to the anode of diode  410 , the time when the user grabs the overmold, the negative voltage represented by  408   a  is simultaneously applied to the anode of diode  409 . This results in anode  410  being forward-biased wherefore it conducts current while anode  409  is simultaneously reverse biased and does not conduct. This causes a positive voltage related to, and synchronized with, pulse  411   a,  a positive trigger pulse, to be applied to resistor  412 , the input control resistor of bistable multivibrator  414 , which causes the multivibrator to change state and remain in that changed state until subsequently triggered again. This change of state allows power to be applied, to the LED during the period of that changed state, and the LED then emits light. 
         [0026]    However, at a future time when negative voltage represented by pulse  411   b  is applied to the anode of diode  410 , the time when the user drops, or stops touching, the overmold, the positive voltage represented by  408   b  is simultaneously applied to the anode of diode  409 . This gives the opposite result of anode  410  now being reverse biased and not conducting current while anode  409  is simultaneously now forward biased and conducting current. This again causes a positive voltage, another positive trigger pulse, but this time related to pulse  408   b,  to be applied to resistor  412  which again causes bistable multivibrator  414  to change state back to its previous state. This return of state removes power from the LED which then shuts off and stays off unless and until bistable multibrator is once again triggered. 
         [0027]    Waveform  415  may represent the output voltage from bistable multivibrator  414 , depicting either zero or non-zero voltage, the non-zero voltage value being sufficient to energize LED  103 . The LED is shut off during the zero voltage value. Edge “a” of waveform  415  coincides with trigger pulse  413   a  and edge “b” of waveform  415  coincides with trigger pulse  413   b.    
         [0028]      FIG. 5  is a timing chart showing the timing of the operation of the circuitry of  FIG. 4  As can be seen impulses  405   a,    408   a,    411   a  and  413   a  all occur virtually simultaneously and coincident with edge “a” of waveform E 415 . Likewise, impulses  405   b,    408   b,    411   b  and  413   b  all occur virtually simultaneously, but at a time subsequent to the occurrence of the “a” impulses, and coincident with edge “b” of wave form E 415 . That subsequent time is shown in  FIG. 5  as T on . This is the time when the LED is turned on by voltage E 415  being applied across LED  103  and resister  416 . Resistor  416  limits the current in the LED to appropriate current levels for the LED. For the duration of the T on  time interval, the voltage E 415  is equal to V on  which is sufficient voltage to keep LED  103  energized for it to emit light. 
         [0029]    The present invention is not limited to USB 2.0 or USB 3.0 cables and their connectors, nor to male only or female only plugs. The present invention is not limited to particular cable lengths of one foot, one meter or two meters; any length of cable may he used, consistent with power supplied by the power source. The present invention may thus have utility in a wider set of applications than only the cell phone battery charging, application described herein as, for example, in lighting up an LED held by a particular connector and thereby identifying that particular connector out of a sea of connectors plugged into a connector array panel. (Notably, a connector panel of 100 connectors by 100 connectors equals a large number of 10,000 connectors,) 
         [0030]    For example, a touch sensitive capacitor circuit of the type shown in  FIG. 4  can be positioned within an overmold in a connector plug (not shown) or jack (not shown) located, at the distal end of cable  104 , i.e., adjacent or abutting power source  205 , instead of being positioned as shown, with wiring running through cable  104  from the power source through the distal plug or jack to an LED, such as LED  103 , in its depicted position at the other end of the cable. In this example, conductors  417  and  418  in  FIG. 4  can be placed within cable  104  for conducting switched power from the distal end to the LED. In other words, power to the LED can be switched on and off by a user touching the overmold of the connector or jack which contains the circuit of  FIG. 4  at the distal location near or adjacent the power source, while the LED remains located at the opposite end of the cable which is plugged into the array. This is accomplished by merely touching the connector near the distal end next to the power source. In this manner, a particular connector, in a sea of connectors, can self-identify by lighting up when the cable is touched at its distal end. For this self-identification application, the LED can be oriented radially, or in some direction other than the direction of axially-oriented. LED  103 , so that its light is clearly visible from a distance. 
         [0031]    in another alternative embodiment, an additional LED can be added to the connector and oriented radially to the direction of axially-oriented LED  103 , thereby having two LED&#39;s in the connector, one directed axially and the other radially, when two LED&#39;s (with the same, or different, light colors) are deemed desirable in a particular application. In this other alternative embodiment, two separate variable capacitance switch circuits similar to  301  are used, one located, proximate the LED&#39;s and the other located in the jack/plug at the distal end, each switch circuit operatively connected to only its respective LED. 
         [0032]    In yet another alternative embodiment, with only one LED used in the connector, such as LED  103 , there are two separate variable capacitance switch circuits each similar to  301  operatively connected to the same single LED, isolating diodes (or “or gate” diodes), similar to the configuration of diodes  409 / 410  in  FIG. 4 , are used, a first such diode (not shown) inserted in the output line  417  with its cathode connected to the anode of LED  103  and the other such diode (not shown) in the power line (not shown) coming from the distal end with its cathode also connected to the anode of LED  103 . The single LED would then be lit in response to operating either switch, in response to a power command via the or gate established by these isolating diodes. 
         [0033]    In a further alternative embodiment, because the LED shall be energized and emit light upon a user&#39;s touching the bottom of the overmold, and because there may be some reason why a lit LED is not desirable at a given moment under a particular circumstance, an additional switch, e.g., a finger-operated button switch, may be incorporated. This additional switch shall override the functionality of variable capacitor switch  301  and cut power from power source  205  over cable  104  that would otherwise feed variable capacitor switch  301 . The button switch may be located within the connector plug proximate the power source at the distal end of the cable, or may he located in the other connector plug which also houses the variable capacitance switch  301 . Alternatively, there may be two such button switches, one in each of those connector plugs, each controlling, power to the LED. 
         [0034]    In this specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The present invention is thus not to be interpreted as being limited to particular embodiments and the specification and drawings are to be regarded in an illustrative rather than restrictive sense.