An optical fiber fusion splicer that heats and fusion-splices optical fibers to each other, the optical fiber fusion splicer includes: a coating clamp installation base; a coating clamp that is attached to the coating clamp installation base and has a coating clamp lid that is openable and closable; and a first power source for advancing the coating clamp installation base and opening the coating clamp lid. An operation of opening the coating clamp lid is performed using the first power source after the fusion splicing is completed.

A support structure for supporting a semiconductor device during a bonding operation is provided. The support structure comprises a body portion defining an upper surface configured to support a semiconductor device during a bonding operation. The upper surface defines a constraining feature for constraining at least a portion of the semiconductor device during the bonding operation.

A material deposition system includes a frame, a support coupled to the frame to support an electronic substrate during a deposit operation, a gantry coupled to the frame, and a deposition head coupled to the gantry. The deposition head is movable over the support by movement of the gantry. The deposition head includes a chamber to hold material, an actuator to push a volume of material out of the chamber, a needle extending from the chamber and terminating in a needle orifice, and at least two air jets located on opposite sides of the needle orifice. A desired volume of material is formed at the needle orifice in response to the actuator, and each of the at least two air jets produce a timed pulse of air to create a micro-droplet from the desired volume and to accelerate the micro-droplet to high velocity.

A liquid feed valve unit is configured to switch between a releasing mode for forcibly opening a valve and a blocking mode for closing the valve, and the valve can therefore be opened and closed in a short time as needed. Since the releasing mode is implemented by pushing the peripheral part and the pressure-receiving part of the flexible member, the flexible member can be prevented from flexing toward the outside of the liquid accommodating chamber even in the case that the pressure-receiving part is pushed. In this case, since a residual pressure can be prevented from forming in the liquid accommodating chamber, there is no need to suspend operation, and it is possible to immediately proceed to the next operation. A fast-operating liquid feed valve unit can thereby be obtained.

A liquid ejection apparatus includes: a head including: a reservoir tank; an inlet opening; and ejection openings; an air-discharge passage for discharging air from the reservoir tank to an outside; a first sucking device for sucking air from the reservoir tank via the air-discharge passage; a semipermeable membrane dividing a space in the reservoir tank and the air-discharge passage, into a reservoir-tank-side space and a first-sucking-device-side space and allowing communication of the air and inhibiting communication of liquid between the reservoir-tank-side space and the first-sucking-device-side space; and a first valve mechanism dividing the reservoir-tank-side space into a first space on a semipermeable-membrane side and a second space on an inlet-opening side, inhibiting fluid from flowing from the first space to the second space, and allowing fluid to flow from the second space to the first space. The first space is located above the ejection openings.

A liquid cartridge is detachably attachable to an apparatus body of an image forming apparatus. The liquid cartridge includes a cartridge case, an information memory element, and a holding unit. The cartridge case includes at least two dividable case parts. The at least two dividable case parts form a front face of the cartridge case to face the apparatus body when the liquid cartridge is attached to the apparatus body. An information memory element is held at the front face of the cartridge case. The holding unit is provided in one of the at least two dividable case parts to hold the information memory element with only the one of the at least two dividable case parts. The holding unit includes a groove to receive the information memory element and a displaceable claw to hold the information memory element between the groove and the claw.

A solid ink stick identification system enables accurate and efficient identification of solid ink sticks in a solid ink imaging device. The solid ink identification system includes an actuator configured to move one of an optical source and an optical sensor between a plurality of predetermined positions. The optical source emits light toward a face of the ink stick, and the optical sensor generates signals corresponding to an amount of reflected light received. A controller identifies features on the solid ink stick based on the signals as the one of the optical source and optical sensor is moved between the plurality of predetermined positions.

A liquid ejection apparatus includes: (a) a storage device for storing an image data set representing a plurality of images; (b) a liquid ejection head for performing an image formation on each recording medium; (c) a curl reduction device for reducing curl caused in each recording medium having the corresponding image formed thereon by the liquid ejection head; (d) an output tray for receiving each recording medium whose curl has been reduced by the curl reduction device, such that the received recording media are stacked on the output tray; and (e) a control device configured to control the curl reduction device, such that the curl caused in an earlier one of the recording media is reduced by a smaller degree than the curl caused in a later one of the recording media that has been subjected to the image formation later than the earlier one of the recording media.

This invention relates to a media multi-feed rejection apparatus, comprising: a plurality of feed rollers; a feed roller driving means operatively connected to one of the plurality of feed rollers; a clutch means operatively connected to the other of the plurality of feed rollers; and a single channel encoder means operatively connected to the clutch means to measure a rotation of the other of the plurality of feed rollers.

An image forming apparatus including a control unit configured to cause the light irradiation unit to irradiate the photosensitive member at an image forming portion to which toner particles adhere with light emitted from the light source by a first light emission amount, and cause the light irradiation unit to irradiate the photosensitive member at a non-image forming portion to which no toner particles adhere with light emitted from the light source by a second light emission amount that is smaller than the first light emission amount. The image forming apparatus further includes an adjusting unit configured to adjust the first light emission amount and the second light emission amount, and an acquisition unit configured to acquire information relating to a speed of surface of the photosensitive member. The adjusting unit is configured to change the second light emission amount according to information acquired by the acquisition unit.

A laser scanning unit includes a laser light source, rotating polygon mirror, drive motor, and entry detection, intensity detection, intensity adjustment, and drive control portions. The laser light source radiates first and second laser lights in first second directions, respectively. The drive motor rotates the polygon mirror reflecting the first laser light. The intensity adjustment portion adjusts the first laser light in accordance with the second laser light detected by the intensity detection portion, until a second time after a first time has elapsed since the first laser light entry detection by the entry detection portion. The drive control portion, upon adjustment by the intensity adjustment portion, drives the drive motor at a first rotation speed, wherein a return light entry timing is included within the first time or from when the second time has elapsed to the timing of the entry detection portion detection.

An image forming device includes a photoreceptor drum including a target surface that is scanned in a main scanning direction and a sub-scanning direction, an exposure head including a plurality of light emitting segments aligned in parallel to the main scanning direction, an exposure driving unit which selectively drives the plural light emitting segments, a storing unit which stores a profile where the respective positions of the plural light emitting segments correspond to a correction amount from the main scanning direction toward the sub-scanning direction at every position, and a correcting unit which smoothes a local change of the correction amount in the profile.

There are provided a substrate for an inkjet head and an inkjet head wherein in a case where a protection layer of heating resistors is energized, an electrical connection with portions around the protection layer is more reliably cut. A first protection layer provided for the substrate for an inkjet head includes individual sections provided at positions corresponding to the plurality of heating resistors and a common section which commonly connects the plurality of individual sections. The individual sections and the common section are connected via connect sections which are eluted and connect in a case where an electrochemical reaction occurs between the connect sections and ink when electricity flow therethrough, so that an electrical connection between the individual sections and the common section is cut.

A method and system for determining a location of a first device that emits a signal: provide at least three sensors separated and spaced apart from each other; at each of the sensors, receive the signal emitted by the first device; determine the received signals for each of the sensors; determine cross-correlations of the received signals for pairs of the sensors; and determine the location of the first device from the magnitudes of the cross-correlations of the received signals.

An electromagnetic wave reverberation chamber includes: an electromagnetic wave absorbing apparatus installed in an intended space of the electromagnetic wave reverberation chamber for adjusting a reflection characteristic of an inside of the electromagnetic wave reverberation chamber, wherein the electromagnetic wave absorbing apparatus have an electromagnetic bandgap structure including a plurality of unit cells arranged periodically.

Disclosed is a detection sensor, which can detect various detection regions even with a small-sized antenna.

A method of determining a filling level of a product contained in a tank using a level gauge system, comprising the steps of: transmitting a first signal towards a surface of the product; receiving a first echo signal; determining a present echo characteristic value based on the first echo signal; and comparing the present echo characteristic value and a stored echo characteristic value. If a difference between the present echo characteristic value and the stored echo characteristic value is greater than a predefined value, the method further comprises transmitting at least a second transmit signal towards the surface; receiving at least a second echo signal; and determining the filling level based on the at least second electromagnetic echo signal.

A system and method of radar location comprises radar signal emission means, an emitted pulse of duration T1 and index i starting at instant T2(i); means receiving reflected radar signals; means determining correlation between reconstruction of an emitted pulse and signal received during the time interval between T2(i)+2*T1 and T2(i+1). The means determining a correlation can reconstruct a set, of at least one truncated pulse j of duration T3(j), less than T1, corresponding to the final part of said emitted pulse, said truncated pulses having increasing respective durations, determining at least one first correlated signal j by correlation of said truncated pulse j and signal received during time interval between T2(i)+T1 and T2(i)+T1+T3(j) and determining a second signal, based on first correlated signals j, by copying the time interval, of said correlated signal j, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1), onto the time interval, of said second signal, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1).

Assisted-GPS for a portable biometric monitoring device is provided. The portable biometric monitoring device may obtain updated ephemeris data from an associated secondary device via a short-range, low-power communication protocol. The secondary device may be a computing device such as a smartphone, tablet, or laptop. Various rules may control when the ephemeris data is updated. The ephemeris data may be used in the calculation of the global position of the portable biometric monitoring device. Additionally, the portable biometric monitoring device may communicate downloaded position fixing data to the associated secondary device. The associated secondary device may then calculate the global position from the position fixing data.

A rover processor determines position of a rover based upon the interaction between multiple antennas located at the rover and multiple antennas located at a base. The rover antennas may include a rover master antenna having a phase center located at the centroid of the antennas patterns of at least two auxiliary rover antennas. The rover processor may determine the position of the rover master antenna based upon the relative positions of at least two rover antennas (e.g., the rover master antenna and at least one rover auxiliary antenna, or at least two rover auxiliary antennas) with respect to at least two antennas of a base transceiver.

A method and apparatus for assisting the calculation of the position of a receiver device (1200), by observing a transmitted signal having a known structure. The method comprises: comparing (S220) the time of arrival, at a reference position (X1), of a first portion of the signal with the time of arrival at the receiver, at an unknown position (Y1), of a second portion of the signal; obtaining (S230) a local wave propagation model of the signal, the model comprising an estimate of the direction of propagation of the signal in the neighborhood of the reference position and unknown position; and using (S240) the direction of propagation and the result of the comparison to assist in the calculation of the unknown position relative to the reference position.

A method for calibrating (700) an antenna array comprises a plurality of antenna elements coupled to a plurality of respective receive paths in a wireless communication system. The method comprises, in receive mode, applying a test signal to an individual single receive path (715) of the plurality of receive paths; and feeding back the test signal via a switched coupler network. The method further comprises running a receive calibration measurement routine to determine at least one measurement value used to calibrate the individual signal receive path and waiting for at least one converged measurement value; and extracting (720) the converged measurement value for at least one individual receive path. The steps of applying, running, extracting for a next individual single receive path are repeated until the calibration routine has completed (725). The method further comprises selecting a converged measurement value of at least one individual receive path from a plurality of receive paths (730) to form a reference receiver calibration result (730); normalizing a plurality of at least one measurement values of the plurality of receive paths using the reference receiver calibration result (730); and applying a normalized value to at least one of the plurality of receive paths.

Devices, systems, and methods for sending positional information from transmitters/beacons are disclosed. In one implementation a transmitter generates a range block including a ranging signal and a hybrid block including positioning data, and sends the range block and hybrid block in predefined slots in a transmit frame. A receiver in a user device receives signals from a plurality of transmitters and generates position/location information using trilateration and measured altitude information in comparison with transmitter altitude information.

A wireless communication terminal includes a communication status measurement element for measuring communication status data representing a communication status of the self terminal at the time of wireless communications; a reference data storage element for storing respective pieces of preset reference data representing communication statuses of a terminal which can be measured at respective locations at the time of wireless communications, in association with respective pieces of location data identifying the respective locations, and a location specifying element for comparing the communication status data measured by the communication status measurement element with the respective pieces of reference data stored in the reference data storage element, and based on the comparison result, specifying a location corresponding to the location data associated with a particular piece of reference data as a location of the self terminal.

Techniques for determining time of arrivals (TOAs) of signals in a wireless communication network are described. Each cell may transmit (i) synchronization signals on a set of contiguous subcarriers in the center portion of the system bandwidth and (ii) reference signals on different sets of non-contiguous subcarriers distributed across the system bandwidth. A UE may determine TOA for a cell based on multiple signals transmitted on different sets of subcarriers. The UE may perform correlation for a first signal (e.g., a synchronization signal) from the cell to obtain first correlation results for different time offsets. The UE may perform correlation for a second signal (e.g., a reference signal) from the cell to obtain second correlation results for different time offsets. The UE may combine the first and second correlation results and may determine the TOA for the cell based on the combined correlation results.

An unmanned aircraft, unmanned aviation system and method for collision avoidance during the flight operation of an unmanned aircraft are provided. The unmanned aircraft includes a lift and propulsion system and a flight control system having a flight control unit, a navigation system and an actuator system. The flight control unit has an autopilot unit. The flight control unit calculates control commands using data from the navigation system and/or the autopilot unit, which can be conveyed to the actuator system for actuating the lift and propulsion system. A collision warning system is connected with the flight control system, the collision warning system detects a collision situation and makes collision avoidance data available. A connection between the collision warning system and the autopilot unit is provided, in order to initiate an obstacle avoidance maneuver by the autopilot unit with the help of the collision avoidance data.

A method, system and computer readable media for route re-planning including generating enemy force movement predictions to be used during mission planning. During a mission, enemy force movements can be compared to the predictions. By using enemy force movement predictions for an initial comparison, the enemy force movements may only need to be compared to the own force mission plan if the enemy forces deviate from the predictions. When enemy force movement deviates from the predictions, new enemy force movement predictions can be generated. The new enemy force movement predictions can then be compared to the own force mission plan to determine if a route re-plan is needed. The route can be re-planned to determine a route that reduces or eliminates the chance of a lethal encounter with an enemy or threat.

A method of synthetic aperture radar autofocus for ground penetration radar. The method includes transmitting a signal via an antenna; receiving a reflected signal comprising a plurality of image blocks via the antenna; reading each image block from the reflected signal via a processor; locating prominent targets in each image block via the processor; estimating ground penetration phase error via the processor in each image block via phase error inputs including pulling range and quantization level by generating a 1D phase error and converting the 1D phase error into a 2D phase error of an image spectra; refocusing each image block according to estimated ground penetration phase error for that image block via the processor; and forming an image mosaic comprising each refocused image block via the processor.

Identification of maximum power scatters in an N-dimensional dataset generally requires two basic steps. The first step is to identify the max power scatters of the dataset and the second step removes neighboring power scatters (e.g., “hits”) of lower power. Current naïve approaches utilize an inefficient and computationally intensive brute force implementation which requires multiple comparisons of each initial “hit” power to all “hits” of lesser power. Such brute force implementations require 2×N×(M−1)! comparisons, where N is the number of dimensions and M is the number of “hits.” Embodiments of the present disclosure utilize vectorization to identify a plurality of neighboring hits for each max power scatter and removes the neighboring hits of lesser power that are within a predetermined isolation region. Advantageously, embodiments of the present invention perform M−1 comparisons.

Disclosed is an object detection device capable of improving object detection accuracy by preventing erroneous combination detection. In this device, a detection object region correction unit (103) corrects a detection object region set by a detection object region set unit (102) on the basis of moving speed map information associated with a coordinate group in a reference image plane and the detected moving speed on each coordinate, which is detected by a radar. Thus, the detection object region can be amended by the use of the moving speed map information even when the detection object region is obtained as a result of erroneous combination. As a result, the object detection accuracy can be improved.

A system for determining a coverage region of a radar device is disclosed. The system may have one or more processors and a memory. The memory may store instructions that, when executed, enable the one or more processors to receive radar data generated by a radar device and lidar data generated by a lidar device. The radar data may include radar data points representing objects detected by the radar device and the lidar data may include lidar data points representing objects detected by the lidar device. The one or more processors may be further enabled to determine a radar coverage region for the radar device by comparing one or more radar data points to one or more lidar data points, and to generate data used to display a graphical representation of the radar coverage region.

This disclosure provides a tracking information control device. The device includes a receiver for receiving, from two radar devices, data relating to a target echo received by a radar antenna of one of the radar devices, and data relating to a target echo received by a radar antenna of the other radar device, the data being obtained from tracking the target echoes, respectively, a determiner for determining whether the target echoes indicate the same target object, an ID applier for applying the same ID to the target echoes when the determiner determines that the target echoes indicate the same target object, and a transmitter for transmitting the same IDs to the radar devices in order to inform whether the target echoes displayed by the radar devices, respectively, indicate the same target object.

A tower crane load location determiner is disclosed. One example includes a load location measurer to provide load location measurement information for a load coupled with a tower crane. In addition, a load position determiner utilizes the load location measurement information to determine a location of the load. A user accessible load location provider provides the determined location of the load.

The present disclosure concerns a method for post-processing of radar data that uses information of Doppler speed as obtained by coherent processing of the input data, to reduce clutter due to waterbodies, in particular the sea clutter. The present disclosure further concerns a coherent radar provided with means suitable to implement the invention method.

A method for processing return radar waveforms in response to transmitted radar waveforms. The method includes receiving, with a processor, a return radar waveform having a Doppler shift larger than Doppler tolerance. The method also includes separating, with the processor, the return radar waveform into a plurality of shortened waveforms. The method also includes compressing, with the processor, each of the plurality of shortened waveforms with a shortened form of the return radar waveform. The method also includes summing, with the processor, the plurality of compressed, shortened waveforms by computing a Doppler Fourier transform for each radar range bin of the return radar waveform using the plurality of compressed, shortened waveforms.

A system mounted to an object for detecting repetitive motion of the object. The system includes a GPS receiver for receiving GPS signals while being maneuvered in a repetitive motion by the object, and a processor for detecting repetitive phase shifts in the received GPS signals. In general, the system computes the repetitive motion of the GPS receiver based on the repetitive phase shifts.

A phased array transmitter includes a plurality of vector modulators, an in-phase/quadrature (I/Q) signal generator, and a multiphase generator. The output phases of the plurality of vector modulators, and hence the direction of transmission of the phased array transmitter, are set and controlled by adjusting both the magnitude ratios of I/Q signal pairs generated by the I/Q signal generator and applied to I and Q inputs of the plurality of vector modulators and phases of a plurality of local oscillator (LO) signal phases generated by the multiphase generator and applied to LO inputs of the plurality of vector modulators. Setting and controlling the output phases of the vector modulators by varying both the magnitude ratios of the I/Q signal pairs and the phases of the LO signal phases allows the output phases of the plurality of vector modulators to be more precisely set and controlled than if the output phases were to be set and controlled only through the LO paths or only through the I/Q signal paths of the plurality of vector modulators.

A method, apparatus, system, and computer program product for auto-installing an integrated receiver/decoder (IRD) includes issuing an auto-installation command from the IRD to an outdoor unit (ODU) and receiving a plurality of tones from the ODU in response to the auto-installation command, each tone representing a center frequency of available user bands (UBs). The auto-installation also includes acquiring a UB center frequency by the IRD, requesting the ODU to confirm a UB number corresponding to the acquired UB center frequency, and receiving confirmation from the ODU that a UB number corresponds to the acquired UB center frequency. The auto-installation also includes sending an acceptance of the assigned UB number from the IRD to signal the ODU that it may mark the assigned UB as assigned.

Techniques for positioning access points and terminals in WLANs and other wireless networks are described. For access point positioning, measurements are obtained for at least one access point in a WLAN. The measurements may be based on transmission sequences (e.g., beacon frames) transmitted periodically by each access point. The measurements may be made by multiple terminals at different locations or a single mobile terminal at different locations. The location of each access point is determined based on the measurements and known locations of the terminal(s). For terminal positioning, measurements for at least one access point in a WLAN are obtained. The location of the terminal is determined based on the measurements and known location of each access point. The measurements may be round trip time (RTT) measurements, observed time difference (OTD) measurements, time of arrival (TOA) measurements, signal strength measurements, signal quality measurements, etc.

A method of determining the orientation of a robotic machine at a worksite contemplates providing a target on the machine, moving the target to a first position on said machine, determining the location of the first position in the worksite, moving the target to a second position on said machine, and determining location of the second position in the worksite. The first and second positions are known with respect to the machine. Finally, a vector between the first and second locations defines the orientation of the machine with respect to the worksite. The target may be moved to additional positions on the machine.

A positive response notification to provide information regarding locate and/or marking operations for underground facilities may include time-stamp information to provide proof of a time at which the locate and/or marking operation was completed by a locate technician, and/or place-stamp information to provide proof of a presence of the locate technician at or near a work site. An electronic manifest image and/or a virtual white line image similarly may be included in a positive response notification. In one example, such images may be bundled together based on respective descriptor files (or descriptor metadata) that associates the corresponding images with a locate request ticket for the operation. In another example, a positive response notification may include environmental information regarding one or more environmental conditions present at or near the work site during the locate and/or marking operation.

A powerline communication (PLC) transmission module transmits a signal over a three-line electrical mains supply. The PLC transmission module includes at least two coupling transformers, each transformer coupling the signal to first and second line-pairs of a three-line electrical mains supply, the first and second line-pairs different from one another. Driving circuitry drives a first version of the signal over the first line-pair and a second version of the signal over the second line-pair. Inversion circuitry selectively inverts one version of the signal relative to the other version of the signal, dependent upon an enacted transmission mode. The inversion circuitry may invert neither/both of the versions of the signal so that the signal is transmitted as a differential-mode signal on the line-pairs or invert one of the first and second versions of the signal relative to the other so that the signal is a common-mode signal.

A power conditioner for a feeding system which stabilizes a load of active power is provided. A power conditioner for a feeding system comprises a first AC-DC and DC-AC converter for performing conversion between AC power and DC power; and a nickel-metal hydride battery disposed between and connected to a high-voltage cable at DC side of the first AC-DC and DC-AC converter and a low-voltage cable at the DC side of the first AC-DC and DC-AC converter.

An output converter includes a DCDC conversion section, a secondary side voltage/current monitoring section detecting a power from the DCDC conversion section, a maximum operation point control section determining what voltage is to be set by the DCDC conversion section so that the power detected by the secondary side voltage/current monitoring section is maximum, a DCDC short-circuit switch via which a current from a module bypasses the DCDC conversion section to outside, a primary side voltage/current monitoring section measuring the current from the module, a module short-circuit switch switching between a state where a secondary side cathode and a secondary side anode are short-circuited and a state where they are not short-circuited, the maximum operation point control section causing the DCDC short-circuit switch and the module short-circuit switch to switch.

According to one embodiment, there is provided a power-fluctuation reducing apparatus in a power generation system to control a converter connected to the power generation system and connected to secondary batteries. The power-fluctuation reducing apparatus includes adjusting direct current voltages output from the secondary batteries, respectively, detecting the directing current voltages output from the secondary batteries, respectively, controlling to adjust the direct current voltages output from the secondary batteries to make the direct current voltages uniform, based on the detected direct current voltages, and controlling the converter to reduce power fluctuations in the power generation system.

An elevator interior illumination assembly comprising a primary LED driver that provides conditioned DC power to primary and backup LEDs when AC power is available from a primary electric power source. The backup LEDs receive DC power from a backup electric power source when AC power is not available to the primary LED driver from the primary electric power source.

A wireless power feeder feeds power from a feeding coil L2 to a receiving coil L3 by wireless using a magnetic field coupling between the feeding coil L2 and the receiving coil L3. The feeding coil L2 is formed so as to be rotated. A power transmission control circuit supplies AC power to the feeding coil L2 to make the feeding coil L2 feed the AC power to the receiving coil L3. The power transmission control circuit rotates the feeding coil L2 to change the opposing area between the feeding coil L2 and the receiving coil L3 as viewed in the axis direction of the feeding coil L2 to thereby adjust the AC power to be supplied from the feeding coil L2 to the receiving coil L3.

An inductive power outlet for providing power to an electric load via an inductive power receiver includes at least one primary inductive coil wired to a power supply via a driver configured to provide a driving voltage across the primary inductive coil such that a secondary voltage is induced in a secondary inductive coil associated with the inductive power receiver. The driver may include a controller configured to receive feedback control signals from the inductive power receiver indicating if more or less power is required. The controller may be further configured to adjust the driving voltage according to the control signals.

An electric motor assembly includes a multi-phase electric motor, a battery of accumulators, an inverter configured to convert the direct current of the battery into multi-phase alternating current adapted to supply the motor, and a connection housing. The connection housing includes plugs allowing connection of motor phases, the battery terminals, and at least five connections to the inverter. The housing further includes a group of contacts allowing it to be connected to a single phase mains system, and a group of contacts allowing it to be connected a multi-phase mains system. The housing includes switches according to the position of which the system including the housing, the battery, the inverter, and the motor connected solely by its phases, alternatively allows the motor to be supplied from the battery, the battery to be recharged directly from a single-phase mains system, and the battery to be recharged from multi-phase mains system.

A communication system has a first communication device, and a second communication device that conducts wireless communication the first communication device. The first communication device has a first transmitter that transmits a signal to the second communication device while modulating the signal, and a first transmission controller that controls the first transmitter. The second communication device has a first receiver that receives the signal from the first communication device and demodulates the received signal. The first transmission controller performs control so as to change a modulation method in midstream when a predetermined first signal is modulated and transmitted. The first receiver changes a demodulation method according to the change of the modulation method of the first signal in midstream when the first signal is received and demodulated.