Abstract: The present invention relates to a MEMS device and related methods comprising a mirror for the measuring of light frequency. The MEMS mirror may rotate around a pivot point and is driven by a periodic force for continuous bi-directional motion without transient vibrations. The periodic force may further comprise transient functions comprising special waveforms when at the turn-around point of the bi-directional rotation.

Abstract: A display device includes a light source, a spatial light modulator, and an optical assembly. The light source is configured to provide illumination light and the spatial light modulator positioned to receive the illumination light. The optical assembly includes an optical element and a curved reflector that is distinct and separate from the optical element. The curved reflector is disposed relative to the light source so that at least a portion of the illumination light is reflected by the curved reflector toward the optical element, is reflected by the optical element toward the curved reflector, and is transmitted through the curved reflector. A method performed by the display device is also disclosed.

Abstract: Disclosed is an optical semiconductor device including a semiconductor laser chip, an insulation substrate, a ground pattern, a mounted pattern, a resistor and an extension ground pattern. The insulation substrate has a surface mounting the semiconductor laser chip thereon. The ground pattern and the mounted pattern are provided on the surface. The mounted pattern has an opposite side opposite to the ground pattern. The resistor is disposed such that a side edge of the resistor separates from an extension region of the opposite side. The extension ground pattern is positioned in the extension region of the opposite side and is electrically connected to the ground pattern. The capacitor is disposed on the mounted pattern.

Abstract: A smart glass transmittance control system includes: a smart glass that decreases transmittance of the smart glass in response to the quantity of light introduced and increases the transmittance of the smart glass when electric power is applied; a power supply unit to supply the electric power to the smart glass; a control unit to control supply of the electric power from the power supply unit to the smart glass in order to control the transmittance of the smart glass according to a user request. In particular, the control unit controls the supply of the electric power from the power supply unit to the smart glass based on the driving environment of a vehicle, the quantity of light from an external light source, or the driving environment condition of the smart glass.

Abstract: Augmented reality glasses including a first image source, a second image source and a lens set are provided. The first image source emits a first image beam. The second image source emits a second image beam. The lens set includes a first lens and a second lens and disposed on the path of the image beams. A gap is disposed between the first lens and the second lens. The refractive index of the gap is lower than that of the first lens. The image beams enter the lens set at an incident surface of the lens set, are reflected at a first surface of the first lens, and exit the lens set at an exit surface. The optical path length of the first image beam from the first image source to the eyes is different from that of the second image beam from the second image source to the eyes.

Abstract: The present disclosure is directed to imaging LiDARs with separate transmit (Tx) and receive (Rx) optical antennas fed by different optical waveguides. This pair of optical antennas can be activated at the same time through a dual-channel optical switch network, with the Tx antenna connected to a laser source and the Rx antenna connected to a receiver. The Tx and Rx antennas can be positioned adjacent to each other, so they point to approximately the same far-field angle. No optical alignment between the Tx and Rx is necessary. This LiDAR configuration, referred to herein as pseudo-monostatic LiDAR, eliminates spurious reflections and increases the dynamic range of the LiDAR.

Abstract: In a general aspect, a laser system includes a laser and a frequency comb generator system. The laser is configured to generate a laser signal, and the frequency comb generator system is configured to generate a frequency comb based on the laser signal. The frequency comb includes frequency comb signals at respective comb frequencies. The laser system also includes a frequency comb dispersion system configured to spatially separate the frequency comb signals onto respective optical channels of the frequency comb dispersion system. The laser system additionally includes a frequency selector system configured to generate a selected frequency signal from the frequency comb signals after separation. The selected frequency signal includes a target separated frequency comb signal. The laser system also includes a frequency shifter configured to alter the selected frequency signal toward a target output frequency of the laser system.

Abstract: A photonic device for detecting rotation and a corresponding method for operation thereof are disclosed. The photonic device includes a readout structure coupled to a ring resonator at one or more coupling points. Light is split between a lower waveguide and an upper waveguide of the readout structure in a forward direction at a beam splitter. The light in the waveguides traveling in the forward direction is coupled into the ring resonator and subsequently back into the waveguides in a reverse direction. The light is spatially phase tilted and is combined at the beam splitter. The combined light is detected by a split detector.

Abstract: A display device includes a light source, a spatial light modulator, and an optical assembly. The light source is configured to provide illumination light and the spatial light modulator is positioned to receive the illumination light. The optical assembly includes a first reflective surface with an aperture and a second reflective surface that is opposite to the first reflective surface. The optical assembly is positioned relative to the light source so that at least a first portion of the illumination light received by the optical assembly is reflected by the second reflective surface toward the first reflective surface, is reflected by the first reflective surface toward the second reflective surface, and is transmitted through the second reflective surface. A method performed by the display device is also disclosed.

Abstract: A spectral feature selection apparatus includes a dispersive optical element arranged to interact with a pulsed light beam; three or more refractive optical elements arranged in a path of the pulsed light beam between the dispersive optical element and a pulsed optical source; and one or more actuation systems, each actuation system associated with a refractive optical element and configured to rotate the associated refractive optical element to thereby adjust a spectral feature of the pulsed light beam. At least one of the actuation systems is a rapid actuation system that includes a rapid actuator configured to rotate its associated refractive optical element about a rotation axis. The rapid actuator includes a rotary stepper motor having a rotation shaft that rotates about a shaft axis that is parallel with the rotation axis of the associated refractive optical element.

Abstract: This disclosure presents an orbital angular momentum (OAM) antenna that includes a plurality of concentric antenna arrays, each antenna array corresponding to a different respective OAM order and being comprised of a different respective set of antenna elements arranged at a different respective radius. The OAM antenna also includes a plurality of phase shifters, each phase shifter corresponding to a different respective antenna array of the plurality of concentric antenna arrays. Each phase shifter is configured to trigger the respective set of antenna elements of a corresponding antenna array to generate a respective OAM beam. According to aspects of the disclosure, each OAM beam generated by a respective antenna array has a same divergence angle as the other OAM beams generated by the other respective antenna arrays of the plurality of concentric antenna arrays.

Abstract: An optoelectronic device for quadrature-amplitude modulation (QAM) and a method of modulating light according to the same. The device comprising: an input waveguide; two intermediate waveguides, each coupled to the input waveguide via an input coupler; and an output waveguide, coupled to each of the intermediate waveguides via an output coupler; wherein each intermediate waveguide includes a modulating component connected in series with a phase shifting component, and each modulating component is connected to a respective electronic driver, the electronic drivers together being operable to produce a QAM-N modulated output from light entering the device from the input waveguide.

Abstract: An electronic device with a display screen includes a first body and a first display screen. The first body has an operation surface, the operation surface has a first side and a second side opposite to the first side, and the first side is defined as a user side. The first display screen is disposed in the first body, and the operation surface exposes the first display screen. The first display screen includes a backlight module and a display panel. The backlight module includes a light guide plate, a light source, and has only one prism sheet. The light guide plate has a light incident surface and a light exit surface, and the light incident surface faces the second side. The light source is disposed between the light incident surface and the second side. The prism sheet is disposed between the light exit surface and the display panel.

Abstract: According to an aspect, there is provided a spectrometer comprising a first and second enclosed volumes. The second enclosed volume is formed by an absorption cell for containing a sample gas. The first enclosed volume of the spectrometer comprises an interferometer with a source of electromagnetic radiation, a first focusing mirror adapted to focus electromagnetic radiation received from the interferometer to the absorption cell, a second focusing mirror adapted to focus electromagnetic radiation received from the absorption cell and a detector adapted to detect electromagnetic radiation focused by the second focusing mirror. Moreover, the spectrometer comprises a main frame plate on which elements in the first enclosed volume are mounted and which is fixed to the absorption cell arranged on an opposing side of the main frame plate.

Abstract: An optical modulating device, a beam steering device, and a system employing the same are provided. The optical modulating device includes an active layer, a driver configured to electrically control a refraction index of the active layer, and a nano-antenna disposed on the active layer, and having a dual nano-antenna structure including a first nano-antenna and a second nano-antenna, the first nano-antenna having a length different from a length of the second nano-antenna, and the first nano-antenna being spaced apart from the second nano-antenna. The driver includes a first driver electrically connected to the first nano-antenna, and a second driver electrically connected to the second nano-antenna.

Abstract: An interferometer system comprises a light redirecting system for splitting an input light beam into two secondary light beams to respectively propagate along a first optical arm and a second optical arm, and for recombining the secondary light beams after exiting the optical arms. The interferometer system also comprises a multipass optical cell positioned at the second optical arm for effecting a predetermined optical path length within the second arm.

Abstract: A laser beam steering device and a system including the laser beam steering device are provided. The laser beam steering device includes a refractive index change layer having a refractive index that changes based on an electrical signal; at least one antenna pattern disposed above the refractive index change layer; a wavelength selection layer disposed under the refractive index change layer and configured to correspond to a wavelength of a laser beam incident onto the laser beam steering device; and a driver configured to apply the electrical signal to the refractive index change layer.

Abstract: Light-based deciphering and transmission of information from one remote party to another in line-of-sight is disclosed. The system speeds the pace of light-based transmissions, the decoding of transmissions, and improves the accuracy of reception of the transmissions. In certain embodiments, the system sends both visual and infrared light to send different types of information to the recipient or to send information under different conditions. Exemplary embodiments disclosed herein demonstrate three exemplary systems (mechanical, LCD, and LED) that are suitable for combination with the other components of the system as disclosed herein. In certain embodiments, the system is configured to focus on the correct light (when there are other lights in view) sending the code (e.g., Morse code or On-Off Keying) and track it.

Abstract: A method includes monitoring a media stream that is streamed over a network at a given media bit-rate in a sequence of traffic bursts. Respective data volumes of one or more traffic bursts of the sequence are estimated, and the given media bit-rate is derived from the estimated data volumes.

Abstract: A projection device includes an illumination system, a light valve, and a projection lens. The illumination system includes a light source, a lens array, a condenser lens, and a wavelength conversion element. The light source is for providing a light beam. The lens array and the condenser lens are disposed on a transmission path of a light beam. The condenser lens is for receiving the light beam passing through the lens array and converting the light beam into a condenser light beam. The wavelength conversion element is for receiving the condenser light beam and converting at least a portion thereof into a converted light beam. The projection device and the illumination system provided by the invention can effectively improve the conversion efficiency of the wavelength conversion element and prevent the wavelength conversion element from damage, and effectively project the converted light beam generated by the wavelength conversion element.

Abstract: A display apparatus that enhances a response speed while suppressing reduction in durability even when the transmittance control is performed. The display apparatus includes a display, a plurality of light adjustment devices, and a controller. The display is configured to be attached to a head of a user to display information to the user. Each of the plurality of light adjustment devices is configured to change a transmittance to adjust an intensity of light incident from outside. The controller is configured to independently control the transmittances of the plurality of light adjustment devices separately from each other.

Abstract: The present disclosure relates a privacy film and a display device including the privacy film. More specifically, by including a light collector including a plurality of first light blocking patterns arranged to be spaced apart from one another, an adhesive layer disposed on the light collector and having at least one first groove in at least a part overlapping the plurality of first light blocking patterns, and a light diffuser disposed on the adhesive layer and including a plurality of capsules, the privacy film and the display device including the privacy film can prevent light discharge efficiency of the privacy film from being degraded and be easily reworked.

Abstract: An optical scanning device includes a light source configured to emit first light in a first wavelength range and second light in a second wavelength range, a beam divider configured to allow the first light to travel in a first direction, and receive the second light, and allow the second light to travel in a second direction different from the first direction, a first optical modulator configured to receive the first light, and modulate a phase of the first light received by the first optical modulator to change a travelling direction of the first light received by the first optical modulator, and a second optical modulator configured to receive the second light, and modulate a phase of the second light received by the second optical modulator to change a travelling direction of the second light received by the second optical modulator.

Abstract: A waveguide display element includes waveguide layers stacked on top of each other and an in-coupler associated with each waveguide layer for coupling light within a predefined wavelength band into the waveguide layer. Each of the in-couplers includes an intermediate layer arranged on the waveguide layer, the intermediate layer having intermediate layer properties. Each of the in-couplers further includes an in-coupling grating arranged on the intermediate layer, the grating having grating properties. The combination of the intermediate layer properties and grating properties of each in-coupler is different with respect to other in-couplers.

Abstract: The invention relates to an optical arrangement having a division element which divides an input beam consisting of a sequence of temporally equidistant light pulses into two spatially separate partial beams, at least one optical element through which at least one of the partial beams propagates, and at least one combination element which spatially superimposes the partial beams in an output beam. It is the object of the present invention to show a method for increasing the pulse energy of light pulses which is improved in comparison with the prior art. The invention solves this problem by virtue of the fact that the combination element superimposes a number of the temporally successive light pulses in a single light pulse in the output beam. The invention also relates to a method for increasing the pulse energy of light pulses.

Abstract: Aspects of the present disclosure describe systems, methods, and structures for aberration correction of optical phased arrays that employ a corrective optical path difference (OPD) in the near-field of an OPA to correct or cancel out aberrations in emitted beams of the OPA including those reaching far-field distances by generating a spatially-varying OPD across the aperture of the OPA that is substantially equal and opposite to an equivalent OPD of the aberration(s).

Abstract: A device for measuring the depth of a weld seam in real time during the welding or joining of a workpiece by means of radiation, including: its measuring light source, the light of which is coupled by a beam splitter into a reference arm and a measuring arm; a collimator module having at least one collimation lens for collimating a measuring light beam, which is fed to the collimator module via an optical waveguide in the measuring arm, and for imaging the measuring light beam, which is reflected from a workpiece to be processed, on an exit/entry surface of the optical waveguide; a coupling element for coupling the measuring light beam into the beam path of a processing beam; a focusing lens for the joint focusing of the measuring light beam and the processing beam on the workpiece and for the collimating of the reflected measuring light beam; and an analysis unit for determining the depth of a weld seam, into which the measuring light reflected from the workpiece is guided with the superimposed, reflected li

Abstract: Aspects of the present disclosure relate to a device for active depth sensing with an adjustable distribution of light projected. An example device includes a light projector. The light projector includes a light source configured to emit a light and a diffractive element. The diffractive element includes a first diffractive optical element having a first refractive index and configured to project a first distribution of light, a second diffractive optical element having a second refractive index and configured to project a second distribution of light based on a refractive material between the first diffractive optical element and the second diffractive optical element, and the refractive material located between the first diffractive optical element and the second optical element. The refractive material is adjustable to have a second refractive index for the first mode and a third refractive index for the second mode.

Abstract: Instruments used to analyze the chemical composition of samples must be calibrated to provide accurate results. Typically, standards are prepared that contain a known amount of the intended analyte to facilitate calibration of the analytical instrument. Various environmental issues are associated with use of mercury containing materials as standards for calibration of analytical instruments. Mercury and gold have very similar characteristic X-ray energies. Standards containing gold nanoparticles have been found to be a good surrogate for mercury in X-ray spectroscopy.

Abstract: An interior rearview mirror assembly for a vehicle includes a mirror casing and an electro-optic reflective element assembly disposed at the mirror casing. The front substrate of the reflective element has a first surface and a second surface and a perimeter edge between the first and second surfaces. The second surface of the front substrate has a transparent conductive coating established thereat. The rear substrate of the reflective element has a third surface and a fourth surface and a perimeter edge between the third and fourth surfaces. The third surface of the rear substrate has a conductive coating established thereat. With the electro-optic reflective element assembly disposed at the mirror casing, the perimeter edges of both the front and rear substrates are exterior the mirror casing and provide a curved transition between the first surface of the front substrate and an outer surface of the mirror casing.

Abstract: Disclosed is an active photonic device having a Darlington configuration with a substrate and a collector layer that is over the substrate. The collector layer includes an inner collector region. An outer collector region substantially surrounds the inner collector region and is spaced apart from the inner collector region. A base layer is over the collector layer. A first outer base region and a second outer base region substantially surround the inner base region and are spaced apart from the inner base region and each other. An emitter layer is over the base layer. The emitter layer includes an inner emitter region that is ring-shaped and resides over and extends substantially around an outer periphery of the inner base region. A first outer emitter region and a second outer emitter region substantially surround the inner emitter region and are spaced apart from the inner emitter region and each other.

Abstract: Disclosed is a beam steering device capable of adjusting a reflection angle of incident light and reflecting the incident light to a desired location. Also disclosed is an optical apparatus configured to detect light reflected from an external object and to extract information with respect to the external object. The beam steering device includes: a substrate; an antenna layer disposed on the substrate; a dielectric layer covering the antenna layer; a refractive index changing layer disposed on the dielectric layer; and an electrode layer disposed on the refractive index changing layer.

Abstract: The present disclosure provides a system and method for an ultrathin optical metasurface with an array patterning formed on an optical fiber facet that enables manipulation of light passing therethrough, such as focusing and steering the light, and controlling a polarization state of light. The patterning can be non-uniform to selectively direct light passing through the metasurface. Array structures can vary in size, angle, shapes, and other non-uniform aspects. Further, the array can include materials that can be electrically activated and controlled to variably tune the metasurface characteristics for increased ability to manipulate the light passing therethrough. The materials can include a conductor, a dielectric, or a composite of a conductor, insulator, and dielectric formed on the optical fiber.

Abstract: Aspects of the present disclosure relate to an adjustable light projector for active depth sensing and flood illumination. An example device includes a light projector that includes a light source to emit a light along a first direction and a diffractive element positioned in a path of the emitted light along the first direction. The diffractive element includes a diffractive optical element having a first refractive index and configured to project a distribution of focused light from the emitted light during a first mode. The diffractive element also includes a diffusion element having a second refractive index and configured to diffuse the emitted light during a second mode.

Abstract: A circular dichroism spectrometer which comprises a metasurface. The metasurface has a plurality of anisotropic antennas configured to simultaneously spatially separate LCP and RCP spectral components from an incoming light beam. An optical detector array is included which detects the LCP and RCP spectral components. A transparent medium is situated between the metasurface and the optical detector array.

Abstract: An X-ray phase contrast imaging device of the present invention can change an arrangement pitch of slits related to a multi-slit and an arrangement pitch of phase shift sections related to a phase grating. A positional relationship among the multi-slit 3b, the phase grating, and an FPD is determined based on the arrangement pitch of the slits related to the multi-slit, the arrangement pitch of the phase shift sections related to the phase grating, and an arrangement pitch of detection elements related to the FPD. Among these arrangement pitches, by changing the arrangement pitch of the slits and the arrangement pitch of the phase shift sections, the present invention can change the positional relationship among the multi-slit, the phase grating, and the FPD.

Abstract: A quantum dot film includes a plurality of sealed microcells. The microcells may be formed within a layer of polymeric material and sealed with a sealing material. Also, the microcells may contain a dispersion of a solvent and a plurality of quantum dots. A method of making a quantum dot film includes providing a layer of polymeric material having a plurality of open microcells, filling the plurality of open microcells with a dispersion of a solvent and plurality of quantum dots, and sealing the microcells.

Abstract: A polymerizable composition of the present invention has favorable solubility, and an optically anisotropic body using the polymerizable composition is unlikely to discolor and is excellent in heat resistance and light resistance. The problem to be solved by the present invention is to provide a polymer obtained by polymerizing the polymerizable composition and an optically anisotropic body using the polymer. The present invention relates to a polymerizable composition which includes a compound having at least one mesogenic group and satisfying an expression represented by Expression (1), and which satisfies an expression represented by Expression (2). 0.

Abstract: A method for controlling the speed of a laser pulse includes a step of applying a chirp to the pulse; and a step of focusing the pulse by means of an optical system having a longitudinal chromatic aberration; whereby an intensity peak of the pulse moves along a propagation axis following, over a finite propagation length, a speed profile dependent on the chirp and on the longitudinal chromatic aberration. The use of such a method for accelerating particles via laser, and a system for implementing such a method, are also provided.

Abstract: An optical transmitter includes an optical modulator including a first modulator, a second modulator, and a phase shifter that provides a predetermined optical phase difference between the first modulator and the second modulator, a light source that makes light enter the optical modulator, and a voltage controller that detects a distortion of light power characteristics from output light of the optical modulator in a state where no data signal is input to the optical modulator to determine a bias voltage to be set in the optical modulator while reducing the distortion.

Abstract: A transparent display for a vehicle that includes a self-emissive display with an electronically adjustable brightness and a masking display with an electronically adjustable absorption. The masking display is arranged back-to-back with the self-emissive display. At least one light sensor that is arranged in proximity to the masking display. A display controller is connected to the self-emissive display, to the masking display and to the at least one light sensor. The display controller is operative to adapt an absorption of the masking display in response to a signal of the at least one light sensor.

Abstract: Various techniques provide optical limiters for facilitating aperture protection. In one example, a system includes an optical device. The optical device includes a photocathode configured to emit electrons in response to an applied voltage and an incident light. The optical device further includes a phase change material. At least a portion of the phase change material is configured to receive the electrons from the photocathode. The portion is further configured to transition from a first phase to a second phase in response to the electrons. The portion is further configured to reflect the incident light when the portion of the phase change material is in the second phase. Related methods and products are also provided.

Abstract: The disclosure is directed to a radio over fiber (RoF) network node, base station, and communication system. In one of the exemplary embodiments, the disclosure is directed to a radio over fiber (RoF) network node which includes not limited to: a laser source which transmits a first laser beam having a first wavelength; a first Electroabsorption Modulated Laser (EML) which modulates a first electrical signal into a second laser beam that is modulated and has a second wavelength; and a first optical coupler which is coupled to the laser source and the EML and transmits an output laser beam having a first carrier frequency which is determined based on a difference between the first wavelength and the second wavelength.

Abstract: The present application provides a manufacture method of an array substrate, wherein the manufacture method comprises providing a substrate; sequentially forming a planarization layer, a first common electrode layer and a first insulation layer on the substrate; forming a metal line layer on the first insulation layer; depositing a second insulation layer on a second metal layer and the first insulation layer; forming a plurality of through holes in the second insulation layer; forming a second common electrode layer on the second insulation layer which is formed with the through holes. The present application further provides a liquid crystal panel and a liquid crystal display screen.

Abstract: An electrical line arrangement, comprising a first and a second electrical line forming a coplanar strip line and at least one terminating resistor terminating the first and the second electrical line, is provided. In a first region of the electrical line arrangement the first and the second electrical line extend in a first distance from one another and in a second region of the electrical line arrangement the first and the second electrical line extend in a second distance from one another that is larger than the first distance. The terminating resistor is physically arranged at a position between the first and the second electrical line in the second region of the electrical line arrangement. At least one electrically conductive structure is arranged between the first and the second electrical line at least partially in the second region of the electrical line arrangement.

Abstract: A foldable display device includes a display panel including a first surface and a second surface opposite to the first surface; and an impact absorption film adjacent to the second surface of the display panel and including first and second impact absorption layers. The second impact absorption layer includes a soft part corresponding to a first region of the second impact absorption layer and a hard part corresponding to a second region of the second impact absorption layer. The first impact absorption layer and the soft part of the second impact absorption layer have an elastic modulus value less than an elastic modulus value of the hard part.

Abstract: To provide a modulation control method and an optical transmission device that realize high reliability by more stably performing bias control of an optical modulator using an optical QAM scheme, an optical transmitter according to the present invention comprises a first waveguide and a second waveguide, wherein each of the first waveguide and the second waveguide are provided with an optical modulator that modulates a carrier light with a modulation driving signal that has multiple strength level values, a phase shift unit that provides a predetermined phase difference between a first optical signal outputted from the first waveguide and a second optical signal outputted from the second waveguide, a light detector that detects and photoelectrically converts a portion of a multiple value optical signal obtained by multiplexing the first optical signal and the second optical signal which have been provided with the phase difference and a control circuit that, on the basis of signal amplitude information obtain

Abstract: A multi-section optical modulator and related method wherein two waveguide arms traverse a plurality of successive modulating sections. A differential drive signal is applied separately to each waveguide arm of each modulating sections in synchronism with the transmission of light along the waveguide arms, effecting a dual differential driving of each section. By suitably selecting the number of modulating sections and the section length, a high modulation bandwidth and a high modulation efficiency may be achieved simultaneously for a given peak-to-peak voltage swing of the drive signal.

Abstract: A circular dichroism spectrometer which comprises a metasurface. The metasurface has a plurality of anisotropic antennas configured to simultaneously spatially separate LCP and RCP spectral components from an incoming light beam. An optical detector array is included which detects the LCP and RCP spectral components. A transparent medium is situated between the metasurface and the optical detector array.

Abstract: A discharge lamp driving device includes a discharge lamp driving unit; and a control unit, in which the control unit controls the discharge lamp driving unit so that a first driving current which causes a first electrode to serve as an anode and a second driving current which causes a second electrode to serve as an anode are alternately supplied to the discharge lamp, a period of the first driving current is changed according to a periodic first pattern, and a period of the second driving current is changed according to a periodic second pattern, in which the first pattern and the second pattern are patterns in which the length of the periods over which the respective driving current is supplied decrease over time within each cycle of the pattern, and in which the cycle of the first pattern is phase-shifted relative to the cycle of the second pattern.