Abstract: An organic light-emitting diode (OLED) device, comprises: a first electrode and a second transparent electrode having one or more organic layers formed there-between, at least one organic layer being light-emitting; and a contrast enhancement element formed on a side of the second transparent electrode opposite the organic layers, wherein the contrast enhancement element comprises a patterned reflective layer for reflecting emitted light and a corresponding light-absorbing layer for absorbing ambient light, wherein the reflective layer is located between the light-absorbing layer and the second transparent electrode and wherein the corresponding layers form one or more transparent openings through the reflective and light-absorbing layers so that light emitted by the light-emitting organic layer passes through the transparent openings.

Abstract: Techniques are described for forming an organic light emitting diode device with improved device efficiency. Materials having at least one energy level that is similar to those of a phosphorescent light emitting material in the diode are incorporated into the device to directly inject holes or electrons to the light emitting material.

Abstract: A polymer light emitting diode having an interinsulation layer between a hole injecting layer (or a hole transporting layer) and a light emitting polymer layer, and a method for fabricating the polymer light emitting diode. The polymer light emitting diode having the interinsulation layer includes a hole injecting layer formed on an anode layer, formed on a glass substrate, by coating or printing; the interinsulation layer having a designated thickness formed on the hole injecting layer; a light emitting polymer layer formed on the interinsulation layer by coating or printing; and an electron injecting layer formed on the light emitting polymer layer, and a cathode layer formed on the electron injecting layer.

Abstract: A blue organic electroluminescent device (1) including at least an emitting layer (40) between an anode (20) and a cathode (60), the emitting layer (40) including a host material and a plurality of dopants, at least one of the dopants having ultraviolet luminescent properties.

Abstract: An organic light emitting diode, and a method of fabricating the same, the organic light emitting diode including a pixel-defining layer disposed on a substrate, the pixel-defining layer having an opening therein and having at least one stepped portion formed adjacent to the opening, and an organic layer disposed in the opening and at least partially covering the at least one stepped portion.

Abstract: An organic electroluminescent display device with an extended lifetime is provided. When at least a hole transport layer HTR, a light emitting layer LUM, an electron transport layer ETR and an electron injection layer EIN are stacked between one electrode (an anode AND or a cathode CTD) formed on the principal surface of an insulating substrate SUB1 and the other electrode (the cathode CTD or the anode AND) by vapor deposition, the concentration of a plasticizer trapped into the layers in a vapor deposition apparatus is limited to less than or equal to 100 ppm.

Abstract: There is provided a display device which quenches ambient light by using only an optical interference effect without additionally using an optical filter such as a color filter, and can provide good visibility out of doors in the daylight. The display device includes a plurality of organic EL elements each having a light extraction electrode, a reflective electrode, and a plurality of organic compound layers disposed between the electrodes, wherein the plurality of organic EL elements include at least organic EL elements which emit a red light, a green light, and a blue light, respectively; a layer comprised of a material having anomalous dispersion is disposed at a location which is on a light extraction side with respect to the reflective electrode in each of the plurality of organic EL elements; and an ambient light reflectance of the display device shows a minimal in a region of 535 nm or more and 575 nm or less.

Abstract: The present invention provides an electroluminescent display device using dielectric spheres embedded in a flexible electrically conducting substrate. Each of the spherical dielectric particles has a first portion protruding through a top surface of the substrate and a second portion protruding through the bottom surface of the substrate. An electroluminescent phosphor layer is deposited on the first portion of each spherical dielectric particles and a continuous electrically conductive, substantially transparent electrode layer is located on the top surfaces of the electroluminescent phosphor layer and areas of the flexible electrically insulating substrate located between the top surfaces of the electroluminescent phosphor layer. A continuous electrically conductive electrode layer coated on the second portion of the spherical dielectric particles and areas of the flexible, electrically insulated substrate located between the second portions of the spherical dielectric particles.

Abstract: The illumination system makes simultaneous use of the color-mixing principle from blue, green and red (RGB mixing) and the principle of converting of a primary radiation emitted by an LED into light with a longer wavelength by a phosphor which absorbs this radiation, with at least two LEDs being used, of which a first LED emits primarily in the range from 340 to 470 nm (dominant wavelength) and a second LED emits in the red region at 600 to 700 nm (dominant wavelength), wherein the green component is produced by the primary radiation of the first LED being at least partially converted by a green-emitting phosphor, the green-emitting phosphor used being a phosphor from the class of the oxynitridosilicates, having a cation M and the empirical formula M(1?c)Si2O2N2:Dc, M comprising Sr as a constituent and D being doped with divalent europium, where M=Sr or M=Sr(1?x?y)BayCaxwith x+y<0.5 is used, the oxynitridosilicate completely or predominantly comprising the high-temperature-stable modification HT.

Abstract: There is provided a light-emitting apparatus formed by attaching a device substrate where light-emitting device is formed and a sealing substrate which seals the device substrate through a sealing material and sealing the light-emitting device between the device substrate and the sealing substrate through the sealing material, wherein the sealing material includes a first sealing material and a second sealing material, wherein the first sealing material is formed to surround the light-emitting device between the device substrate and the sealing substrate and to have a sealing hole portion formed by not disposing the first sealing material, so that the first sealing material is discontinuous, wherein the sealing hole portion of the first sealing material is closed with the second sealing material, so that the second sealing material and the first sealing material constitute a ring-shaped sealing member, and wherein the first sealing material is provided with guide portions which are formed to be continuous wit

Abstract: An envelope (2) has a glass bulb body (4) and a cylindrical glass bulb base (5). The glass bulb body (4) includes an upper hemisphere (4a) and a lower hemisphere (4b). The upper hemisphere (4a) is curved in a substantially spherical shape. The lower hemisphere (4b) is substantially curved in a spherical shape and connects the upper hemisphere (4a) and glass bulb base (5). A photocathode (11) is formed on the inner surface of the glass bulb body (4). An avalanche photodiode (APD) (15) is disposed on the glass bulb body (4) side relative to an intersection (S) between an imaginary extended curved surface (I) of the lower hemisphere (4b) within the glass bulb base (5) and an axis (Z). When light enters the photocathode (11), electrons are emitted from the photocathode (11). The electrons are converged at the position above and in the vicinity of the APD (15) by an electrical field in the electron tube (1), so that the electrons enter the APD (15) in an efficient manner and are detected satisfactorily.

Abstract: In an image display device having in an airtight container an electron source and an image display member that receives electrons from the electron source, an evaporating getter and a non-evaporating getter are stacked in the airtight container. This makes it possible to maintain the vacuum level in the airtight container. The image display device thus obtains a prolonged life and a stable display operation.

Abstract: An electrodeless discharge lamp comprising: an airtight container bulb made of a transparent material and enclosing a discharge gas; and a coupler (coil assembly body), contained in a cavity formed in the bulb, for generating a high frequency electromagnetic field by conducting a high frequency current in a coil to excite the discharge gas so as to emit light, wherein the coupler comprises: a pipe-shaped cylinder formed of a thermal conductor for heat release; a skeleton-shaped bobbin mounted on an outer surface of the cylinder along an axial direction of the cylinder; a core made of a soft magnetic material provided at an opening formed by the skeleton of the bobbin and being in substantial surface contact with the cylinder; and a coil wound around a surface of the skeleton-shaped bobbin and the core.

Abstract: The present invention relates to a plasma display panel, more particularly, to a plasma display panel apparatus and manufacturing method of the same, which is capable of minimizing a gap between a seal layer and a UV Ultra Violet ray/silicon desiccant layer due to an air bubble, when the front panel and the rear panel of the plasma display panel are in the sealing process. A plasma display panel according to the present invention comprises a front substrate; a rear substrate; a seal layer which is formed between the front panel and the rear panel; and a desiccant layer which is in contact with the front panel, the rear panel and the seal layer.

Abstract: Disclosed are an electron emission thin-film with improved secondary electron emission characteristics compared with conventional ones, a plasma display panel including the electron emission thin-film, and their manufacturing methods. Using a vacuum deposition system, a protective layer that is an MgO thin-film is formed on a dielectric layer formed on a front glass substrate. At the time of deposition, angles that lines linking the central point of a target material for the protective layer respectively with the central point and both ends points of the front glass substrate form with the front glass substrate are exclusively in a range of 30 to 80°. This enables at least some of MgO columnar crystals constituting the protective layer to have flat planes that are inclined with respect to the surface of the thin-film.

Abstract: An aluminum resonator for an electrodeless lighting system includes an inner space configured to receive an electrodeless bulb that emits light by plasmarizing light emitting materials filled inside of the electrodeless bulb. The resonator is configured to transmit light generated by the electrodeless bulb, and the resonator is also configured to shield microwaves generated by a microwave generator and applied to the inner space of the resonator, from discharging to an exterior of the resonator, so that the microwaves are transferred to the electrodeless bulb thereby implementing a resonance mode.

Abstract: A lamp comprising a burner (1) and a cap (2) to connect the lamp with a lampholder. The shape of the cap (2) determines the type of lampholder to which the lamp can be connected. Said shape of the cap (2) is established after the burner (1) and the cap (2) of the lamp are assembled. Preferably, said shape of the cap (2) is established by breaking away a break away part (8) provided at the cap (2).

Abstract: A lamp (50) has a lamp envelope (10) having a body (12) with a bottom (14) having a lead-in accepting channel (18); a seat (22) formed with the bottom (14) adjacent one of the lead-in accepting channels; a light source capsule (51) having two electrical lead-ins (52, 54) extending therefrom and through the lead-in accepting channel (18; and an electrical contact (24) having a first depending leg (26), an intermediate transverse portion (28) including a seat engager (30) adapted to cooperate with the seat (22), and a projecting leg (32) extending away from the intermediate transverse portion (28) and along a side (34) of the bottom (16), the first depending leg (26) being in mechanical and electrical contact with one of the lead-ins (54).

Abstract: The present invention discloses a new type of electrodeless light sources, which can be achieved by radiating microwave on an inorganic carbide with electrical conductivity. The inorganic carbide can be carbon nanotubes (CNTs), or graphite-related fiber materials with well-order crystalline structure. The inorganic carbides of the present invention also emit high-brightness white light source in low vacuum condition (less than 10 torr) and induce plasma gas discharge emission in the presence of a trace of inert gas molecules such as nitrogen and argon. The electrodeless light source of the present invention not only emits high-brightness light emissions but also performs low thermal-radiation conversion.

Abstract: The present invention relates to an ultraviolet lamp comprising a glass shell and an electrode fixed on one or more ends of the lamp, where each electrode is a coiled wire with a hollow conical shape. The hollowed conical structure of the electrode reduces the thermal capacity of the electrode as compared with other types of electrodes of the same mass, makes the lamp start quicker, and decreases the emission loss of the electrode when the glow discharge is transformed to an arc discharge. The lamp of the present invention has a wide electrode surface area, such that the loads on each point of the emissive surface are equally distributed, thus decreasing the electron scattering and dispersion, and allowing the lamp to resist the impact from positive ions. Due to the shape and structure of the electrode, the lamp of the present invention has increased efficiency and emitting ability, and allows for a longer lasting lamp.

Abstract: A metal halide discharge lamp with which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: A multifunctional light which uninterruptedly has illuminating function in both the cases that the civil power is supplied and the civil power is cut off. The multifunctional light includes a lamp, a civil power circuit for providing civil power, a spare circuit for providing spare power, a controller bridged between the lamp, the civil power circuit and the spare circuit and a current stabilizer. According to the control of a user and whether the civil power is supplied, the controller selectively connects the lamp with the civil power circuit or the spare circuit. The controller can be electrically connected to a detection system to also have an emergency detection function.

Abstract: An elevator cab includes primary and auxiliary light sources. A light sensor responsive to light from the primary light source causes activation of the auxiliary light source when the primary light source fails. The light sources are inside the cab for passenger use and/or outside the cab for maintenance worker use. A battery for auxiliary light is selectively charged by first and second current levels in response to the battery voltage being above or below first or second different thresholds.

Abstract: A driving circuit for providing a control signal to a power semiconductor device for providing power to a filament lamp, said driving circuit comprising an oscillator for generating said control signal. The driving circuit may further comprise a soft start circuit which controls said oscillator so as to avoid excessive current in said lamp at start-up; a voltage compensation circuit which controls said oscillator so as to compensate for variations in load; a shutdown circuit for shutting down and automatically restarting said oscillator in response to a fault condition; an adaptive dead time circuit which controls said oscillator for providing cool running of said power semiconductor device; and/or a dimming circuit which controls said oscillator for driving said lamp. The driving circuit and its control circuitry may be implemented in an integrated circuit.

Abstract: A high temperature operation type electrodeless bulb of a plasma lighting system includes: a luminous unit defining a space for enclosing luminous materials, and made of glass having selective permeability that transmits visible light generated from the luminous unit and reflects infrared rays to the interior; and a supporting unit extending from the luminous unit to have a particular length and supporting the luminous unit.

Abstract: A resonator for an electrodeless lighting system may include an inner space configured to receive an electrodeless bulb that emits light by plasmarizing a light emitting material filled inside of the electrodeless bulb. Additionally, the resonator may have light transmission holes configured to shield microwaves, generated by a microwave generator and applied to the inner space, from being discharged to an exterior of the resonator. Thus, the resonator may be configured to transmit light emitted from the electrodeless bulb. Further, the resonator may be provided with a low aperture ratio portion that has a low aperture ratio extending from a predetermined region in a circumferential direction of the resonator, and a high aperture ratio portion that has a higher aperture ratio than the low aperture ratio portion. In this regard, the high aperture ratio portion may be formed in the remainder of the circumferential direction of the resonator.

Abstract: In one aspect, an impedance component which exhibits a high impedance in a high frequency region is arranged on a high pressure line formed on a secondary side of a transformer. The potential difference generated at both ends of the impedance component is used to detect an abnormal electrical discharge generated in the high pressure line. When the abnormal electrical discharge is detected, a switching operation is stopped by a controlling circuit, whereby a protection operation is performed.

Abstract: The current-balancing circuit for lamps of the present invention adopts a plurality of transformers having a primary winding and a secondary winding. One end of the secondary winding of the transformer is connected with a lamp and another end of the secondary winding of the transformer is connected with an AC power via the primary winding of a neighboring transformer. By the above linking method, the power provides and balances the working current for the lamps via the transformers, and improves upon the drawbacks, including the inductance on the coils of the prior art being different and it not being able to be applied to lamps with an odd quantity and only can be applied to the lamps with an even quantity.

Abstract: A solid-state light engine comprised of light emitting diodes (LEDs) configured into a bridge rectifier with a current limiting module coupled to the LED bridge rectifier. The light engine may be packaged for high temperature operation. Optionally, the LEDs comprise wavelength-converting phosphors with a persistence that is a multiple of the peak to peak current period, to smooth and mask ripple frequency pulsation of emitted light.

Abstract: The driving and control device according to the present invention provides a desired switched current to a load including a string of one or more electronic devices, and comprises one or more voltage conversion means, one or more dimming control means, one or more feedback means and one or more sensing means. The voltage conversion means may be a DC-to-DC converter for example and based on an input control signal converts the magnitude of the voltage from the power supply to another magnitude that is desired at the high side of the load. The dimming control means may comprise a switch such as a FET, BJT, relay, or any other type of switching device, for example, and provides control for activation and deactivation of the load. The feedback means is coupled to the voltage conversion means and a current sensing means and provides a feedback signal to the voltage conversion means that is indicative of the voltage drop across the current sensing means which thus represents the current flowing through the load.

Abstract: A multiple axis servo control implements a multi-tasking PWM control unit to provide PWM signals for multiple axes in a single unit. A time slice mechanism provides axis selection signals based on a system clock signal to permit control parameters of the selected axis to be processed to control the selected motor drive axis. The single unit PWM control mechanism eliminates complex and costly multiple axis networks typically associated with independent servo motor controls for each axis in a multi-axis system. A single PWM unit implementation also permits the reduction of components for closed loop current control and closed loop velocity control in the multi-axis servo control system.

Abstract: A apparatus processes an object (19), such as a semi-conductor wafer at accurately controlled positions. The object (19) is supported by a working platform (12) that is moveable along a path. A suspension actuator part (14) attached to the working platform (12), contains a soft magnetic core (24) with poles facing the surface of a soft magnetic element (34) on the support structure along the path and a winding (20) for application of a current to generate a magnetic field that runs through the core (24) via the poles and returns via the soft magnetic element (34). A sensor (17) senses a measured position of the suspension actuator part (14) relative to the position reference element (16). A control circuit comprises an outer control circuit (40) and an inner control circuit (42). The outer control circuit (40) receives a sensing result and determines force set point information to regulate the measured position of the actuator part (14) to a required value.

Abstract: A selectively configurable electric motor comprises a stator and a plurality of poles electrically coupled to the stator. The selectively configurable electric motor also includes an actuator separated from the poles by an air gap and configured to move relative to the stator in the presence of an electromagnetic field. The selectively configurable electric motor further includes a plurality of electric conductors, each of the plurality of electric conductors substantially wound around one of the plurality of poles. The selectively configurable electric motor also includes a power converter, at least a portion of which is coupled to the plurality of electric conductors, including a plurality of switching elements configured to selectively couple one or more of the plurality of electric conductors in a predetermined electrical configuration.

Abstract: Methods for evaluating back electromotive force (EMF) in a polyphase motor is described. The methods include monitoring back EMF in the motor after a commutation of the motor, and evaluating the back EMF only after a back EMF event occurs after the commutation of the motor. The methods may also include monitoring a total current appearing on all phase windings of the motor after a rotor of the motor begins to rotate, and evaluating back EMF only after the total current is within a predetermined margin of the current supplied to the motor. Systems implementing the methods are also described.

Abstract: A method for determining an initial position of a rotor of a polyphase motor is described. The method comprises determining current change values from a plurality of phases of the motor during saturation of the motor relating to the initial position of the rotor; identifying a set of modelled current change values according to a modelled behaviour of the motor, in which the modelled current change values represents modelled positions of the rotor under the modelled behaviour; and comparing the current change values to the set of modelled current change values to identify the initial rotor position from the modelled positions. A system implementing the method is also described.

Abstract: A PWM controller device of a simple cooling fan includes a fan motor, a driver device, and a PWM controller device. The driver device is electrically connected to the fan motor. The PWM controller device is electrically connected to the fan motor and the driver device. The driver device internally detects the temperature rise variation of the electronic element and drives the fan motor to rotate in high speed. When the fan motor remains in high rotational speed as the temperature of the electronic element decreases, a PWM signal is input to the PWM controller device, which responsively generates a voltage-drop signal to drive the fan motor to its reduce rotational speed. The PWM controller device achieves control similar to that of a MCU, reduces manufacturing costs, and reduces over all physical size of the cooling fan. The invention is suitable for use in compact electronics.

Abstract: The invention relates to an electric power tool having a control and/or regulating device for an electric motor. It is provided that the control and/or regulating device (4) is assigned an electronic memory element (5) for at least one operating state of the electric motor (1).

Abstract: A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor.

Abstract: When surplus power not charged to an electric storage is generated at the time of regenerative braking of a vehicle, a voltage is generated across first and second neutral points using a zero-voltage vector each of first and second inverters and the generated surplus power is consumed by a resistance connected across the first and second neutral points. The voltage generated across the first and second neutral points is calculated in accordance with the surplus voltage, using a resistance value of the resistance.

Abstract: A motor is controlled by a motor control signal so that it reaches a target state, which is derived from sensor data sensed by a sensor. The motor can be put into a rest state at the occurrence of an error in simple and efficient manner by means of a safety means generating an alternative motor control signal at the occurrence of the error. Thus, the underlying idea is, instead of redundantly embodying components, to consciously accept a failure and integrate a corresponding fall-back solution into the overall concept. The failure is detected, and the motor is switched off in a user-manageable manner by a targeted shutdown.

Abstract: A method for attenuating switching noise from back electromotive force (EMF) observations in a motor is described. The motor is controlled by pulse width modulation (PWM) signals provided at a PWM frequency. The method comprises sampling back EMF observed in the motor at a sampling frequency at least two times greater than the PWM frequency to obtain over-sampled back EMF readings; and filtering the over-sampled back EMF readings to remove switching noise and obtain cleaned back EMF observations. A system implementing the method is also described.

Abstract: A method for adjusting a rotational speed of a rotor in a polyphase motor from a first speed towards a second, faster speed when the motor is commutating according to a commutation scheme at a first commutation phase angle is described. The method comprises selecting an advanced phase angle relative to the first commutation phase angle for commutating the motor; and adjusting the commutation scheme to be commutating at the advanced phase angle, so that the rotational speed of the rotor increases from the first speed towards the second speed as the motor is commutating at the advanced phase angle. A system implementing the method is also described.

Abstract: A system for controlling a polyphase motor is described. The system comprises phase windings in the motor for energizing stators to cause rotational motion of a rotor of the motor as energy is applied to one or more phase windings, and a bridge circuit having a branch circuit connected to one of the phase windings of the motor. The branch circuit has a first FET, a second FET, and a capacitor to trigger the gate of the first FET. The capacitor is connected at one end to the junction between the first and second FETs. While the second FET is conducting, the capacitor is charging. While the first FET is conducting, the charge on the capacitor alone is used to hold the first FET in a conducting state. A method for controlling the motor with the system is also described.

Abstract: An integrated motor monitoring system includes a housing and a motor disposed within the housing, the motor being configured to provide a power output. The integrated motor monitoring system also includes at least one monitoring device communicatively coupled to the motor and configured to monitor an operational aspect of the motor and generate a data signal associated with the operational aspect. The integrated motor monitoring system further includes a controller, disposed within the housing and in communication with the at least one monitoring device, and configured to energize a plurality of field conductors of the motor and receive the data signal from the at least one monitoring device over at least one of the plurality of field conductors.

Abstract: A servo control system micro-electromechanical systems (MEMS)-based motion control system (and method therefor), includes a motion generator having an inherent stiffness component.

Abstract: A piezoelectric debris sensor and associated signal processor responsive to debris strikes enable an autonomous or non-autonomous cleaning device to detect the presence of debris and in response, to select a behavioral mode, operational condition or pattern of movement, such as spot coverage or the like. Multiple sensor channels (e.g., left and right) can be used to enable the detection or generation of differential left/right debris signals and thereby, enable an autonomous device to steer in the direction of debris.

Abstract: In a method of estimating a magnetic pole position in a synchronous motor, an alternating current voltage having ?- and ?-axes components in an ?? coordinates system representing a two-phase alternating current coordinates system is applied to the motor, and ?- and ?-axes components of an alternating current are detected from the motor. A wave height of the alternating current changing with time is approximated to a wave height not depending on time, so that a differentiated value of the wave height with respect to time is substantially set at zero. An induced voltage of the motor is calculated from the components of the alternating current voltage and the components of the alternating current. The magnetic pole position is estimated from the induced voltage.

Abstract: It is an object of the invention to provide a control device for a synchronous motor which can detect the position of a magnetic pole from a zero speed without requiring a signal generator. The invention provides a control device for a synchronous motor which drives the synchronous motor through a voltage-operated PWM inverter and controls a torque and a speed of the motor, including means (6-3) for causing a PWM carrier signal to have an arbitrary phase difference between two phases such as UW, VW or WU in three phases of U, V and W, means (11) for extracting a high frequency voltage and a high frequency current which are thus generated from a detecting voltage or a command voltage and a detecting current, and means (12) for estimating a position of a magnetic flux or a position of a magnetic pole by using the high frequency voltage and the high frequency current which are extracted.

Abstract: A method of and apparatus for controlling an electric machine.

Abstract: A light emitting charger is provided. The light emitting charger delivers light energy to a portable electronic device having a rechargeable battery. The electronic device is equipped with a photovoltaic energy conversion device that converts the transferred light into an electrical current that can be used to charge the battery. Through alternate communication mechanisms, the electronic device can alert the charger as to when to illuminate the light sources and which light sources to illuminate. The charger is equipped with photo detectors for receiving photo communication from the electronic device. In one embodiment, the charger periodically pulses one or more light sources until it receives light reflected from reflective material disposed along the electronic device. When the reflective light is received, the charger may actuate a plurality of light sources in a predetermined pattern corresponding to the amount or location of the reflective light.