In a method for calibrating a star probe of an image measuring machine, the star probe includes one or more probe heads. Probe configuration information for the star probe is configured when there is no probe configuration file of the star probe stored in a storage device of the image measuring machine, and one of the probe heads to be calibrated is selected from the star probe. The method calibrates a radius value of the selected probe head, and calibrates the deviation between the center point of the selected probe head and the focus of the camera lens. The method further generates a star probe model of the star probe according to the probe configuration information and the probe calibration information, and displays the star probe model of the star probe on a display device of the image measuring machine.

A planning and guiding method and excavation guiding device correctly implant an artificial tooth root at a predetermined site, perform various excavation processes on a cortical bone section and a spongy bone section by stage-based guidance, and guide eccentric excavation of the cortical bone section and concentric excavation of the spongy bone section according to a bone pattern, such that the artificial tooth root thus implanted is not only positioned at a planned ideal site but also manifests appropriate initial stability.

An orthodontic apparatus for installation in a patient's mouth is disclosed. The orthodontic apparatus includes a first extension wire, a second extension wire, and a palatal archwire. Each of the first and second extension wires includes a proximal portion and a distal portion. The proximal and distal portions and the palatal archwire are manipulatable to apply corrective buccal, labial, and transverse forces on the patient's dento-alveolar complex (DAC), to correct the shape of the patient's palate.

A cement system for forming an implant comprises a reactive glass ionomer cement (GIC) powder, a polycarboxylic acid or salt, and a filler. The polycarboxylic acid or salt is included to initially provide a paste having a pH less than 7 when the cement system is mixed with water. In one embodiment, the filler is substantially inert when mixed with water and is selected from (CaO)(AI2O3)6, (CaO)(AI2O3)2, calcium silicate (CaOSiO2), and mixtures thereof. In another embodiment, the filler is substantially reactive when mixed with water and is selected from (CaO)2(SiO2), (CaO)3(SiO2), and mixtures thereof, and the cement system includes an additional acid to maintain the paste at a pH less than 7 for at least one hour after the cement system is mixed with water.

The present invention relates to oral and dental care and cleaning agents comprising an aqueous dispersion of a phosphate-containing and/or phosphonate-containing polyurethane polymer and anionic surfactant(s), to tooth cleaning methods using these agents, and to the use of oral and dental care and cleaning agents comprising an aqueous dispersion of a phosphate-containing and/or phosphonate-containing polyurethane polymer and anionic surfactant(s) to reduce the restaining of teeth and/or to reduce biofilm development on dental surfaces and/or to reduce the adhesion of bacteria to dental surfaces and/or to extend the antibacterial action of antibacterial substances.

The present invention provides an intraoral imaging and illumination apparatus (10) comprising a rear portion (12) and a front portion (14) removably connected to the rear portion (12). The front portion (14) is formed as a light guide (29). The rear portion (12) comprises an imaging device (16) and an illumination device (18). The illumination device (18) is adapted to couple light into the front portion (14) and towards a leading end (30) of the front portion (14) opposite the rear portion (12) so as to illuminate a first object (66). The imaging device (16) is adapted to image the first object (66).

An archwire for use with a passive self-ligation orthodontic bracket is described and which includes a resilient main body which is received in the archwire slot, and which further has a predetermined width dimension, and a variable thickness dimension, and wherein the variable thickness dimension of the archwire can be varied so as to facilitate an adjustable application of a force to the passive self-ligation orthodontic bracket so as to achieve a clinician selectable and controllable second and third order movement of a patient's tooth.

A dental carrier comprises a thermoplastic carrier. The thermoplastic carrier has a pattern structure. After heating the thermoplastic carrier, the thermoplastic carrier is provided with a user to be impressed by teeth or alveolar ridge for forming teeth or alveolar ridge model of the user. Compared to the prior art, the dental carrier of the present invention can provide the dental medicament contained in the pattern structure to be precisely applied and hold onto the treatment area and the medicament can be evenly coated on the teeth, root, or periodontal tissue for the treatment of teeth. When the dental carrier is not used to carry medicament, the pattern structure can improve the mechanical strength and fitness of the dental carrier to be used as a biteplate, orthodontic retainer, periodontal dressing for treatment or protection or mouth guard in sports.

Methods are provided for regulating tooth movement and for maintaining or improving tissue health using heavy forces. Such methods comprise allowing a heavy force to be exerted on one or more teeth of a patient in need thereof; and administering an effective amount of light to the maxillary or mandibular alveolar bone of the patient, wherein the light is administered before, during, or after the heavy force is exerted. The light can have a wavelength in the range of about 585 nm to about 665 nm, or about 815 nm to about 895 nm. An apparatus useful for providing light therapy is also provided.

Techniques and methods for utilizing ion implantation to modify dental archwires are provided. An example of a method of ion implanting a wire target includes providing the wire target in an ion implant system, implanting ions into the wire target such that a color of the wire target material after the implanting exhibits a changed appearance from the color of the wire target material before the implanting, and removing the wire target from the ion implant system. An example of a copper-aluminum-nickel (CuAlNi) wire includes an ion implanted atomic species wherein a color of an implanted CuAlNi wire is white, off-white and/or silver and further wherein the implanted CuAlNi wire exhibits mechanical properties of an unimplanted CuAlNi wire.

Methods and apparatus are provided for generating computer 3D models of an object, by registering two or more scans of physical models of an object. The scans may be 3D scans registered by a curve-based registration process. A method is provided for generating a 3D model of a portion of a patient's oral anatomy for use in dental restoration design. Also provided are scanning workflows for scanning physical models of an object to obtain a 3D model.

A mouthpiece delivery apparatus and methods for the using the same are provided. In at least one specific embodiment, the mouthpiece delivery apparatus can include: a mouthpiece that can include a top receiving wall, a bottom receiving wall, a first side wall and a second side wall, where the bottom receiving wall can include a base member and an edge member; an adapter section, where the adapter section is configured to attach to a dispensing apparatus; and a body section, where the body section is attached to the mouthpiece at a first end and attached to the adapter section at a second end.

A torque converter, including: an axis of rotation; a cover arranged to receive torque from an engine and including a first indentation; an impeller shell fixedly secured to the cover; at least one impeller blade fixedly secured to the impeller shell; a turbine including a turbine shell and at least one turbine blade fixedly secured to the turbine shell; and a lock-up clutch including a first carrier plate fixedly secured to the cover and including a first protrusion disposed in the first indentation and a clutch plate non-rotatably connected to the first carrier plate.

A twin plate separation system, comprising a pressure plate, an intermediate plate facing the pressure plate, and a spring separator assembly. The spring separator assembly comprises a mounting extending out from the intermediate plate towards the pressure plate. A spring surrounds the mounting, and the spring is biased to push the pressure plate and the intermediate plate apart. The mounting or another fixture can secure at least one drive strap to the intermediate plate. Alternatively, the mounting extends out of the pressure plate towards the intermediate plate, and the spring surrounds the mounting and is biased to push the pressure plate and the intermediate plate apart. In this alternative, the intermediate plate does not comprise a hole for receiving the mounting.

A vehicle includes a continuously variable transmission, a gear mechanism and a controller. The continuously variable transmission and the gear mechanism are provided in parallel with each other between an input shaft and an output shaft. The controller is configured to i) when the vehicle travels in a state where both a first clutch and a third clutch provided on the gear mechanism side are released, gradually increase a hydraulic pressure of the first clutch such that the first clutch is engaged, ii) calculate a command hydraulic pressure for setting the first clutch to a pressure regulating state on the basis of a command hydraulic pressure of the first clutch at a timing at which the amount of change in an output-side rotation speed of the first clutch becomes larger than a predetermined value, and iii) control the first clutch by using the calculated command hydraulic pressure.

The present invention relates to a lockup apparatus for a torque converter and aims to obtain a smooth relative movement of a equalizer plate with respect to a deformation of a drive plate. The drive plate 26 as an inlet sided rotating member is connected to a driven plate 22 as an outlet sided rotating member by means of damper springs 28 in a rotating direction. The damper spring 28 is constructed by a pair of divided parts 28A and 28B. An equalizer plate as an intermediate member 29 is arranged so as to slide rotatably on bearing parts 26-1 of the drive plate 26 and supporting parts 40 fixed to the equalizer plate 29 are arranged between the divided parts 28A and 28B of the damper springs 28. The bearing part 26-1 of the drive plate 26 has an outer peripheral surface 26-1a', of which arc shape has a center C' of a curvature which is offset from the center C of the arc shape of the inner peripheral surface 29a of the equalizer plate 29.

The invention relates to a device for actuating a clutch-controlled transfer case having a two-stage intermediate gearing and a clutch-controlled transfer case that has a two-stage intermediate gearing and that is equipped with such a device. The device comprises: a rotatably driven selector shaft,a drive for rotating the selector shaft,a clutch cam disk, which can be rotated about a clutch cam disk axis by means of the selector shaft, andat least one scissor lever, wherein: one end (06) of at least one scissor lever is guided in a gate provided on the clutch cam disk,the gate has a curved path for each scissor lever, in which curved path the end of the scissor lever associated with the curved path is guided,the curved path winds around the clutch cam disk axis by at least 360°,the curved path has at least one helical segment having a continuously increasing or decreasing distance from the clutch cam disk axis, along which segment one end of a scissor lever guided therein experiences a continuously increasing or decreasing change in deflection with respect to the clutch cam disk axis during a rotation of the clutch cam disk with increasing angle of rotation, andthe clutch cam disk is disposed in such a way that the clutch cam disk can be rotated with respect to the selector shaft between two stops by an angle-of-rotation range such that, by means of rotation of the selector shaft within the angle-of-rotation range situated between said stops, shifting back and forth between the shifting stages of the intermediate gearing occurs, and, by means of rotation of the selector shaft beyond the angle-of-rotation range, the end of the at least one scissor lever experiences a deflection for actuating the clutch while a selected shifting stage is maintained.

A method for operating a vehicle drive-train having a continuously power-branched transmission with secondary coupling. In the open operating condition of reversing clutches of a reversing gear unit, torque applied in the area of a drive output can be supported by a range group in the area of a variator. In the event of a command to interrupt the power flow between a drive engine and the drive output, it is checked whether the vehicle is on an inclined surface and if the result of that inquiry is positive, the power flow between the drive engine and the transmission is interrupted at the latest when the rotational speed of the drive output is reduced to zero by opening the reversing clutches, while the active connection between the drive output and the variator is maintained by way of the range group.

A synchronization unit of a switchable gear changing transmission for a vehicle. The synchronization unit includes a friction ring having an outer installation surface and a synchronizer ring having an inner installation surface. The outer installation surface of the friction ring is shaped as a first geometrically structured profile. The inner installation surface of the synchronizer ring is shaped as a corresponding second geometrically structured profile. The first profile of the friction ring is configured to engage with the second profile of the synchronizer ring in such a manner that the friction ring is secured in the radial direction to the axis and in the circumferential direction at the synchronizer ring.

A damper device has a dynamic damper that includes a mass body and vibration absorption springs that couple the mass body and an intermediate member to each other. The vibration absorption springs are arranged side by side with outer springs in the circumferential direction. The mass body has spring abutment portions that abut against end portions of the vibration absorption springs. The intermediate member has first outer spring abutment portions that abut against end portions of the outer springs and second outer spring abutment portions that abut against end portions of the vibration absorption springs on the radially inner side with respect to the spring abutment portions. The first outer spring abutment portions extend toward the radially outer side with respect to the second outer spring abutment portions.

A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

A one-way clutch is configured to allow rotation in one direction with respect to a shaft and regulate rotation in the other direction, and includes a housing, a plurality of needles, a plurality of magnets, a plurality of first accommodating portions, and a plurality of second accommodating portions. The housing includes a fitting hole into which the shaft is fit. The plurality of magnets are respectively arranged adjacent to the plurality of needles. Each magnet has an S pole and an N pole corresponding to a first end side and a second end side of one of the needles, and attracts one of the needles by magnetic force to a first circumferential direction of the shaft. The plurality of first accommodating portions accommodate the plurality of needles, respectively. The plurality of second accommodating portions are respectively arranged adjacent to the first accommodating portions, and respectively accommodate the plurality of magnets.

Systems and methods for applying markings to an article are disclosed. One aspect comprises providing a dye pad shaped to correspond to a desired marking; applying an infusion dye to the dye pad; applying an activation solution to the infusion dye, thereby forming an infusion dye mixture; placing the dye pad in contact with a discrete area of an outer surface of the article; leaving the dye pad in contact with the outer surface of the article under room temperature and pressure, for a duration sufficient to allow the infusion dye mixture to open a polymeric structure of a material of the outer surface and to allow the infusion dye to penetrate the outer surface and form the desired marking within a substrate of the article; and removing the dye pad from the outer surface. An infusion dyeing kit and method for supplying a kit are also disclosed.

The present application relates to encapsulated benefit agents, compositions comprising such encapsulated benefit agents and processes for making and using compositions comprising such encapsulated benefit agents that do not require or require a reduced amount of scavenger materials. Such encapsulated benefit agents, compositions comprising such encapsulated benefit agents are processed such that no or lower levels of scavenger materials are required.

This application relates to thiophene azo dyes for use as hueing agents, laundry care compositions comprising such thiophene azo dyes, processes for making such thiophene azo dyes, and laundry care compositions and methods of using the same. The thiophene azo dyes contain a formally charged moiety and are generally comprised of at least two components: at least one chromophore component and at least one polymeric component. Suitable chromophore components generally fluoresce blue, red, violet, or purple color when exposed to ultraviolet light, or they may absorb light to reflect these same shades. These thiophene azo dyes are advantageous in providing a hueing effect, for example, a whitening effect to fabrics, while not building up over time and causing undesirable blue discoloration to the treated fabrics. The thiophene azo dyes are also generally stable to bleaching agents used in laundry care compositions.

An apparatus and method for detecting an imbalance in the laundry load and effecting a redistribution of the imbalance by reducing the rotational speed of the treating chamber such that part of the load may redistribute while part of the load remains satellized, without ceasing rotation, and increasing the rotational speed back to a spin speed after redistribution.

The invention discloses a laundry article used for both cleaning and conditioning fabrics comprising a water-insoluble nonwoven substrate and coated thereon into at least one zone each a detergent composition and a fabric conditioning composition. The fabric conditioning composition comprises a quaternary ammonium cationic surfactant, an alkoxylated fatty alcohol and a fatty acid.

A process obtains an aged or faded effect on garments made of protein fibers such as wool, cashmere and silk. Granules of inert materials, which are particularly light in order not to damage very fine fibers, are introduced into a tumbler. The garments were previously treated with a chemical product commonly referred to as “dye retardant” for inhibiting dyeing of the fabric. The tumbler is pre-arranged so that the chemical product does not migrate through holes or openings. Raw confectioned garments that are to be treated, such as jerseys or outerwear, are introduced into the tumbler. The garments are extracted from the tumbler at the end of migration of the chemical product for inhibiting dyeing of the outer surface of the garments by the granules and steamed in an autoclave to fix the chemical process of the product for inhibiting dyeing of the outer surface of the garments. The garments are then dyed with a specific selection of dyes that must be defined each time according to the desired result.

The present invention provides dye mixtures containing at least one dye of formula (I) and at least one dye of formula (II) where T1, T2, R1 to R9 and n are each as defined in claim 1, processes for their preparation and their use.

A bluing composition concentrate comprises an aqueous medium and at least one colorant that exhibits a blue or violet shade when deposited onto a textile material. The concentrate can be used to produce a bluing composition, and the bluing composition can be used to treat textile materials in such a way as to decrease the visually-perceived yellow coloration of textile articles that can occur with repeated use and laundering.

Concentrated cleaning formulations for removing debris from hard surfaces and textile surfaces. An exemplary formulation includes a mixture of the following chemical components, in specified proportions: glycerin;monopropylene glycol;triethylene glycol methyl ether;a non-ionic surfactant;an emulsifier;soya methyl ester or canola methyl ester, or both; andhydroxypropyl sulfonate; The formulation is free of water other than insignificant amounts present in the chemical components combined to make the mixture. Combining the formulation with water causes a temperature of the combination to increase above the temperatures of the water and the formulation before combining.

A charge pump circuit includes a capacitor, a first switch between the capacitor and a power supply terminal, a second switch between the capacitor and an output terminal, a third switch between the output terminal and the capacitor, a fourth switch between the capacitor and a ground terminal, and a control unit configured to generate control signals for the switches. The control signals include first signals generated during a first period that cause first and third switches to be in an ON state and second and fourth switches to be in an OFF state, second signals generated during a second period that cause first and third switches to be in an OFF state and second and fourth switches to be in an ON state, and third signals generated between the first and second periods, that cause the ON/OFF state of each of the switches to be switched at different times.

An active filter device and a circuit arrangement comprising an active filter device are disclosed. In an embodiment the active filter device includes sensor terminals for applying a sensor signal depending on a sensed noise signal, an output terminal for providing a correction signal that is suitable for reducing the noise signal, a signal source adapted for generating a correction signal and a high-pass filter coupled between the sensor terminals and the signal source, wherein the correction signal is generated with a dependence on a high-pass filtered sensor signal.

A system includes a voltage-controlled oscillator (VCO) to generate an output signal based on an input voltage and a multi-stage delay network to receive the output signal from the VCO. Each stage of the delay network produces a phase-shifted output signal. The system includes a multi-stage digital-to-analog converter (DAC) network, where each stage of the DAC network is associated with a corresponding stage of the delay network. Each stage of the DAC network receives the phase-shifted output signal from its corresponding stage of the delay network and generates a weighted output signal based on the received phase-shifted output signal. The DAC network combines the weighted output signal of each stage. A weighting factor for each stage of the DAC network is selected to reduce harmonic content of the combination of weighted output signals.

Capacitors connected between gate terminals of a plurality of parallel-connected power transistors are charged and discharged in each switching cycle to provide a plurality of power transistor control waveforms from a single gate driver waveform that equalize power losses/temperatures or steady-state currents among the plurality of power transistors. The capacitors are charged to different voltages by diverting current from one transistor driver by disabling another power transistor driver at different respective times in response to measured transient or steady state current or temperature or other operational parameter.

A clock generation circuit may include a reference clock generator configured to generate a pair of first reference clocks in an offset code generation mode, a correction code generator configured to generate a reference correction code according to a duty detection signal based on a phase difference between the pair of first reference clocks, and an offset code generator configured to generate an offset code based on the reference correction code and a preset reference code.

In some embodiments, a phase-locked loop (PLL) system comprises a phase-frequency detector (PFD) configured to compare a phase-frequency reference signal and a feedback signal, a charge pump (CP) electrically coupled to the PFD and configured to produce a first tuning signal based on an output of the PFD, multiple integrator cells electrically coupled to the CP and configured to output multiple second tuning signals based on a voltage of the first tuning signal relative to a voltage reference signal, and a voltage-controlled oscillator (VCO) electrically coupled to the CP and to the multiple integrator cells and configured to adjust a capacitance value of the VCO based on the multiple second tuning signals. The capacitance value and the first tuning signal affect a frequency of the feedback signal.

An apparatus includes an integrated circuit (IC). The IC includes a power controller, which includes a regulator and a controller. The regulator receives a plurality of input voltages and provides a regulated output voltage. The controller controls the regulator to generate the regulated output voltage from the plurality of input voltages. The power controller provides power to a load integrated in the IC from a set of arbitrary input voltages. The set of arbitrary input voltages includes the plurality of input voltages.

A system includes a SiC semiconductor power device; a power supply board that is configured to provide power to a first gate driver board via a connector; the first gate driver board that is coupled and configured to provide current to the SiC semiconductor power device, wherein the first gate driver board is coupled to the power supply board via the connector, and wherein the first gate driver board is separated from the power supply board; and an interconnect board that is coupled to the first gate driver board, wherein the interconnect board is configured to couple the first gate driver board a second gate driver board.

A semiconductor apparatus may include a noise determination circuit, a strobe signal control circuit, and a reception circuit. The noise determination circuit may sense and determine noise of a reference voltage, and generate an up control signal and a down control signal. The strobe signal control circuit may adjust a transition timing of a strobe signal in response to the up control signal and the down control signal, and output a control strobe signal. The reception circuit may generate internal data signal in response to external data signal, the reference voltage, and the control strobe signal.

A radio-frequency (RF) switch includes a field-effect transistor (FET) disposed between a first node and a second node, the FET having a source, a drain, a gate, and a body. The RF switch further includes a coupling circuit including a first path and a second path, the first path being connected between the gate and one of the source or the drain via a first resistor in series with a first capacitor, the second path being connected between the body and the one of the source or the drain via a second resistor in series with a second capacitor, the coupling circuit configured to allow discharge of interface charge from either or both of the gate and body.

Methods and systems include constructing and operating a semiconductor device with a mid-band dopant layer. In various implementations, carriers that are optically excited in a mid-band dopant region may provide injection currents that may reduce transition times and increase achievable operating frequency in a bipolar junction transistor (BJT). In various implementations, carriers that are optically excited in a mid-band dopant region within a thyristor may improve closure transition time, effective current spreading velocity, and maximum rate of current rise.

A nonaqueous electrolyte secondary battery of the present invention includes a positive electrode containing olivine-structured Fe or a Mn-containing phosphorus compound as a positive electrode active material; a negative electrode containing a titanium-containing metal oxide capable of inserting and extracting lithium ions as a negative electrode active material; a nonwoven fabric separator, which contains an electrically insulating fiber and is bonded to a surface of at least one of the positive electrode and the negative electrode; and a nonaqueous electrolyte. In a thickness direction of the nonwoven fabric separator, a density of the fiber on a side having contact with the positive electrode is high, and a density of the fiber on a side having contact with the negative electrode is low.

The present invention provides a nonaqueous electrolyte secondary battery separator that achieves an excellent rate characteristic by having a tensile creep compliance J satisfying at least one of the following three conditions in a case where stress of 30 MPa is applied for t seconds: (i) when t=300 seconds, J=4.5 GPa−1 to 14.0 GPa−1, (ii) when t=1800 seconds, J=9.0 GPa−1 to 25.0 GPa−1, (iii) when t=600 seconds, J=12.0 GPa−5 to 32.0 GPa−1.

A separator for a rechargeable battery and a rechargeable lithium battery, the separator including a porous substrate; and a heat-resistant porous layer on at least one surface of the porous substrate, wherein the heat-resistant porous layer includes a filler and a copolymer including a structural unit of vinylidenefluoride, a structural unit of hexafluoropropylene, and a structural unit of a carboxyl-containing monomer, the structural unit of hexafluoropropylene is present in an amount of about 4 wt % to about 10 wt %, based on a total weight of the copolymer, and the structural unit of a carboxyl-containing monomer is present in an amount of about 1 wt % to about 7 wt %, based on the total weight of the copolymer.

A secondary battery includes a case composed of a metal containing aluminum as a main component, a stacked electrode assembly arranged in the case, a negative electrode current collector electrically connecting negative electrodes of the stacked electrode assembly to a negative electrode terminal, a positive electrode current collector electrically connecting positive electrodes of the stacked electrode assembly to a positive electrode terminal, a first metal plate arranged between the case and the stacked electrode assembly, and a spacer arranged between the case and the first metal plate, the spacer being composed of an insulating material. The positive electrodes are electrically connected to the case or a second metal plate arranged on the first metal plate with an insulating member provided between the first metal plate and the insulating member. The negative electrode current collector is in contact with the first metal plate to establish electrical connection between the negative electrode current collector and the first metal plate.

A secondary battery is disclosed. In one aspect, the secondary battery includes a case accommodating an electrode assembly, a cap plate sealing an opening of the case, an electrode terminal electrically connected to the electrode assembly and disposed over the cap, and an insulating member provided between the cap plate and the electrode terminal and configured to insulate the electrode terminal from the cap plate. The battery also includes a connection tab disposed over the electrode terminal, and a safety device having a portion positioned under the connection tab and electrically connected to the electrode terminal via the connection tab. The safety device has at least one of electric conductivity and thermal conductivity greater than that of the connection tab, and at least a part of the safety device is seated on the insulating member.

The object of the present invention is to provide a positive electrode active material usable for a lithium ion battery capable of high charge/discharge cycle performance and high discharge capacity. The positive electrode active material for a lithium secondary battery has a layered structure and comprises at least nickel, cobalt and manganese. Further, the positive electrode active material satisfies requirements (1) to (3) below: (1) a primary particle size of 0.1 μm to 1 μm, and a 50% cumulative particle size D50 of 1 μm to 10 μm, (2) a ratio (D90/D10) of volume-based 90% cumulative particle size D50 to volume-based 10% cumulative particle size D10 of 2 to 6, and (3) a lithium carbonate content in a residual alkali on particle surfaces of 0.1% by mass to 0.8% by mass as measured by neutralization titration.

The positive electrode as an embodiment includes a positive electrode current collector mainly composed of aluminum, a positive electrode mixture layer containing a lithium-containing transition metal oxide and disposed above the positive electrode current collector, and a protective layer disposed between the positive electrode current collector and the positive electrode mixture layer. The protective layer contains inorganic particles, an electro-conductive material, and a binding material; is mainly composed of the inorganic particles; and is disposed on the positive electrode current collector to cover the positive electrode current collector in approximately the entire area where the positive electrode mixture layer is disposed and at least a part of the exposed portion of the positive electrode current collector where the positive electrode mixture layer is not disposed on the surface of the positive electrode current collector.

The present invention relates to a positive electrode active material for a sodium secondary battery, and a method for preparing the same. The positive electrode active material for the sodium secondary battery according to the present invention is structurally more stable by replacing a part of the transition metal with Li, and accordingly, the thermal stability and life characteristics of the sodium battery including the positive electrode active material are greatly improved.