Abstract: A liquid discharge apparatus includes: a liquid discharge head configured to discharge a liquid in a discharge direction onto a liquid application target; a stage configured to hold and move the liquid application target in a conveyance direction orthogonal to the discharge direction, a carriage on which the liquid discharge head is mounted; a guide holding the carriage movable in a main scanning direction orthogonal to each of the discharge direction and the conveyance direction; a pair of holders respectively holding sides of the guide in the main scanning direction; and multiple eccentric cams contacting the pair of holders, the multiple eccentric cams rotatable to move at least one of the pair of holders in at least one of the conveyance direction or the discharge direction to adjust a position of the carriage or the guide.

Abstract: A linear permanent magnet motor may include a stator unit having a coil, a mover including an array of permanent magnets, and a position sensing device operable to determine a position of the mover. The mover is arranged to move along a motion direction. The position sensing device has a sensing element operable to sense a magnetic field of the array of permanent magnets The sensing element is fixed to the stator unit. The array of permanent magnets is spaced apart from the stator unit by an air gap in which electromagnetic fields created by the array of permanent magnets and by coil are configured to interact thereby generating traction. The sensing element is positioned such that it is within a magnetic leakage field of the array of permanent magnets when the array of permanent magnets is positioned in correspondence with the sensing element.

Abstract: An inkjet printer includes a head, a drive voltage generating circuit, a carriage, and a magnet array. The head includes a nozzle and an ejection element. The ejection element is configured to be driven, when applied with a drive voltage, to eject ink from the nozzle. The drive voltage generating circuit is configured to generate the drive voltage to be applied to the ejection element. The carriage is configured to move in a moving direction to move the head and the drive voltage generating circuit in the moving direction. The magnet array includes a plurality of magnets arrayed in the moving direction. The drive voltage generating circuit includes a coil configured to produce an electromotive force by interlining with magnetic flux of the magnet array in accordance with movement of the carriage. The drive voltage generating circuit generates the drive voltage using the electromotive force produced by the coil.

Abstract: A printing apparatus includes a carriage mounted with a printing unit; a first motor configured to move the carriage in a predetermined direction; a second motor configured to move the carriage in the predetermined direction; and a control unit. The control unit executes a first mode in which, when causing the printing unit to perform printing under a first printing condition, the first motor is driven in a first direction and the second motor is driven in the first direction, and a second mode in which, when causing the printing unit to perform printing under a second printing condition different from the first printing condition, the first motor is driven in the first direction and the second motor is driven in the first direction while changing an output ratio between the first motor and the second motor.

Abstract: The present disclosure relates to a method for reducing and homogenizing residual stress of a component, which comprises: detecting stress value(s) of regulation portion(s) of the component; placing the component in a container containing a fluid medium so as to immerse the component in the fluid medium; emitting, by an acoustic wave generator, an elastic wave to the fluid medium in a manner of emitting towards the regulation portion(s) of the component, and determining an emitting period of time and a frequency of the elastic wave based on the stress value(s); returning to the step S1 when the emitting period of time has elapsed, until the stress value(s) is stable. The method and the device solve the problems that it is difficult to reduce and homogenize the residual stress on high-precision machined components, complex structural components, thin-walled structural components, and low-stiffness components.

Abstract: A device for moving an object is disclosed. The device has a drive cylinder with drive grooves and a set of idler pulleys. The idler pulleys are on a shaft that is parallel to the drive cylinder. Each of the idler pulleys rotate at an angle around the drive shaft that aligns the grooves of the idler pulleys to neighboring drive grooves. This allows the line to pass onto the drive groove, around an idler pulley, and onto a next adjacent drive groove. The line therefore winds back and forth between the drive grooves, the idler pulleys, and back to the next drive groove. One end of the line is placed under tension and the other is attached to an object or to a fixed member. The drive cylinder is driven and the line is moved through the device, or the device is moved along the line, respectively.

Abstract: Provided is a differential member that is used in a surgical instrument, which may be manually operated to perform laparoscopic operations or various surgical operations, to receive an input of two or more rotation motions or translation motions and output a single rotation motion or translation motion.

Abstract: The invention relates to a printing apparatus that performs printing by scanning a carriage that has a print head in a main scan direction. The printing apparatus according to an aspect of the present invention includes: a carriage motor that drives the carriage; a control unit that controls the driving of the carriage motor; a memory unit that stores a plurality of patterns of velocity data regarding at least either one of scanning speeds of the carriage after start of the scanning and driving speeds of the carriage motor corresponding to the scanning speeds of the carriage; and a driving mode switchover unit that switches over the patterns of the velocity data, wherein the control unit controls the driving of the carriage motor in such a manner that the carriage is scanned on the basis of the velocity data selected by the driving mode switchover unit.

Abstract: A print head is operable to perform printing with respect to a medium. A motor is operable to move the print head. A guide unit is operable to guide the print head along a predetermined direction. A determination unit is operable to determine whether or not the print head performs a stick-slip operation. A motor control unit is operable to generate a command value for controlling the motor when moving the print head. The motor control unit generates a command value for moving the print head at a predetermined target speed on the basis of determination of the determination unit that the print head does not perform the stick-slip operation and generates a command value for moving the print head at a target speed faster than the predetermined target speed on the basis of determination of the determination unit that the print head performs the stick-slip operation.

Abstract: According to the claimed invention, a positioning apparatus is disclosed. The positioning apparatus comprises a motor and a Scotch yoke for controlling the position of a first printer part. The motor is for providing a rotational motion to the Scotch yoke. In response, part of the Scotch yoke moves in a linear fashion. As a result of the linear motion of the Scotch yoke, the position of the first printer part can be controlled.

Abstract: A recording apparatus can improve stability of the speed of a carriage without increasing the production cost. The recording apparatus for performing recording by discharging ink from a recording device onto a recording medium includes a carriage adapted to convey a recording head, and a conveying member adapted to drive the carriage using a belt stretched between pulleys connected to corresponding ones of two motors. A driving force for the carriage by the two motors is differently distributed.

Abstract: A carriage driving apparatus that drives a carriage of a printer or the like by a motor and a motor control method for controlling the motor can substantially eliminate variation in control accuracy among individual apparatuses. Each set of various parameters are determined with respect to each ultimate target speed of the carriage and each moving direction, and contained in a table. Three kinds of tables, i.e. a table for heavy load, a table for light load and a table for standard load in accordance with the difference in load applied to individual drive systems of the carriage, as well as one kind of table for low temperature are prepared and stored on a ROM. It is determined which of the three kinds of tables should be selected at normal temperature by actually driving the carriage in the final step of the manufacturing process.

Abstract: A low rotational inertia shuttle system (24) for a dot matrix line printer (20) is disclosed. The low rotational inertia shuttle system (24) includes an elongate support structure (26), a carriage (22) and a counterbalance (62). The carriage and the counterbalance are reciprocally mounted on the support structure. The low rotational inertia shuttle system also includes a reciprocating assembly (60) disposed on the support structure for reciprocating the carriage and the counterbalance. The reciprocating assembly has an inertia that is purposely minimized with respect to the mass of the carriage and the counterbalance, such that the printer operates at a substantially constant level of kinetic energy to produce a substantially linear velocity profile for the carriage.

Abstract: An impact printer having one or multiple lines of hammers on a hammerbank for impacting a print ribbon against a print media after release by one or more electrically energized coils in a magnetic circuit with one or more pole pieces retaining the hammers prior to impact. One or more of the coils has a spaced winding thereby allowing filling of the spaced winding during return winding. Another embodiment utilizes a longitudinal return from an initial winding which can be formed with multiple layers or multiple overlappings of the longitudinal return. The foregoing minimizes a first dimension while having controlled wire crossing resulting in expansion in a second dimension, thereby allowing compaction of magnetic circuits in the first dimension.

Abstract: A print head motor control system uses a desired function of print head position versus time and a measured print head position to form an error signal. The print head controller forms a motor drive signal from the sum of a first term corresponding to the square root of the absolute value of the error signal and a second term corresponding to a dead band signal having a predetermined slope if said error signal exceeds a predetermined value. The desired function of print head position versus time may be formed by double integrating a desired function of print head acceleration versus time. The print head motor control preferably also includes a velocity loop subtracting a print head velocity estimated from the measured print head position from the sum. The print head motor control is preferably implemented using a microprocessor.

Abstract: A printer assembly includes an idler pulley, a printhead carrier belt, an idler-pulley spring, and a ratchet stop. The printhead carrier belt is operatively connected to the idler pulley and extends in an inboard direction from the idler pulley. The idler-pulley spring biases the idler pulley in an outboard direction to maintain belt tension as the belt lengthens during wear. The ratchet stop is located inboard of the idler pulley and operatively engages the idler pulley against movement of the idler pulley in the inboard direction, wherein such inboard movement would cause printing errors.

Abstract: An automatic alignment system is used to correct the offset error of a bidirectional printing device. The positional offset between the forward printing and the backward printing is compensated by adjusting the position of the printing cartridge. The actual position of the cartridge is sensed by a light detector, which is shuttered when the moving cartridge, driven by a microstepping motor, passes through the sensor. Based on the difference between the actual position and the correct theoretical position, the cartridge position is automatically adjusted to correct the offset error. For fine adjustment, time delay can be used in addition to the positional adjustment of the cartridge.

Abstract: The invention relates to an arrangement for mounting a print head in a printer. The arrangement comprises a frame (1) to which a feeder device feeds a material to be printed which the printer will print on by means of a print head (3), movably arranged adjacent to a print roll (2) for being brought into, or out of, contact with the material to be printed. According to the invention, the arrangement uses a magnet (5) to hold the print head. Preferably, the print head is fitted in a fixture device (4), which is pivoting freely around a rear axle (7) parallel to the print roll, and the pressure is applied on the print head by a pressure member (6). The magnet (5) is preferably attached to the pressure member (6) so as to transfer pushing as well as pulling forces. The invention enables screws or fixed mounting of the print head to be avoided. The arrangement according to the invention also allows for the print head (3) pressure point to be transversally displaced.

Abstract: Disclosed is a multi-functional apparatus having a small size. The multi-functional apparatus according to the present invention includes a body including a section for transferring a recordable paper and a service station formed at an outside of the recordable paper transferring section; a guide mounted along an entire width of the body in a vertical direction to be normal to a recordable paper transferring direction; and a carriage which has a printhead and a scanner module mounted thereon and moves reciprocally along the guide to be across the recordable paper transferring section, the carriage being positioned in the service station when a scanning or printing operation is normally completed, wherein the scanner module is mounted on the carriage to be adjacent to the recordable paper transferring section with reference to the printhead.

Abstract: A linear shuttle motor assembly used for reciprocally moving a printer head includes a rotor and a stator having the same mass. A loud, i.e., the printer head, is connected to the stator and a counter balance to the rotor. The rotor and the stator are driven to reciprocally move in mutually opposite directions. A 180 degree phase synchronizing mechanism is used to synchronize phases of the rotor and the stator. The mechanism is fixed to a housing and connected to the rotor and the stator. By this configuration, the amount of power transmission loss is reduced to a minimum, which improves energy conversion efficiency.

Abstract: A method and apparatus for operating stepping motors in a printer or copier senses temporarily changes in the moment of resistance caused by the introduction of the leading edge of the paper and overcomes this change in moment by changing the current amplitude to the motor windings. The currents are modified at a starting time, as determined by sensors.

Abstract: A higher-performance, energy saving recording apparatus, having a stepping motor as a driving source, presumes an out-of-phase state of the stepping motor. Driving setting parameters of the stepping motor are changed when an out-of-phase state of the stepping motor is presumed.

Abstract: A printing apparatus and control method facilitating the development of application software that can be used with different printers when the horizontal and vertical pitches of their respective mechanical transports vary. Based on a received base pitch calculation command, the printing apparatus calculates and stores a conversion coefficient for converting the minimum physical pitch values of the printer mechanism to virtual base pitch values. Thereafter, the printing apparatus executes motion commands and directs relative motion of the head and/or selected recording medium transport in accordance with this virtual pitch value.

Abstract: The method for driving a stepping motor for printers comprises the generation of first pulses (16A,16B) at n levels recorded in registers and representing a simulation of sinusoidal waves. The maximum level is applied during two consecutive microsteps to one of the phases of the motor, while the level of the other phase changes sign. During a motor stopping command, second pulses (VCA,VCB) are applied to the registers and to the two phases of the motor and are programmed so as to ensure, during the last microstep, an exact stopping position, such that all the stopping positions are kept apart by a whole number of half steps. Very precise, fast and noise-free printing is thus attained. The resolution is doubled, without any loss of precision or speed.

Abstract: A recording apparatus includes: a carriage that relatively moves against a recording medium, on which a recording head for recording an image of input information on a recording region of the recording medium is mounted; and a driving device for driving the carriage. Furthermore, the recording apparatus includes: a control device for driving the carriage by the driving device in accordance with a driving process of: an acceleration step for accelerating the carriage by stepwise changing the carriage's velocity from a rest level to a predetermined level and a retaining step for keeping the carriage's velocity of the predetermined level as a predetermined velocity.

Abstract: An ink jet recording apparatus has a recording head mounted on a carrier which is shifted by a stepping motor in recording. The stepping motor is also utilized as a power source of a recovery system device. The drive mode of the stepping motor for the recovery system is differentiated from that for the recording.

Abstract: A dot matrix printer and motor having hammers forming in part a hammerbank and a counterbalance mechanically linked to the hammerbank with a link to the position of the motor. The motor includes coils positively driven and then negatively driven after current in the coils has at least partially decayed. The current in the coils is allowed to decay further after negatively driving the coil. The motor coils are connected to an H bridge having transistors which can be formed in a full H bridge or half bridge. A controller switches the transistors to cause negative and positive flow through the H bridge for positive current flow from a reference level to an upper reference level, and a decay of current within the coils to an intermediate reference. The coils are then driven with a negative current from the intermediate reference level to a second intermediate reference level afterwhich the current within the coils decays to a lower or initial reference level.

Abstract: A printer including a driving shaft having first, second and third worms for feeding a recording paper, advancing a printing ribbon, and moving a carriage, respectively. The third worm for moving the carriage may be replaced by a belt. The driving shaft may include two separate portions, with the first, second and third worms connected to ends of the separate portions. The driving shaft may be rotatably supported adjacent the first, second and third worms.

Abstract: A dot matrix printer having a plurality of hammers on a hammerbank with a counterbalance for the hammerbank in adjacent parallel relationship to the hammerbank. The hammerbank and counterbalance are driven by a first crank arm connected to the hammerbank and a second crank arm connected to the counterbalance with looped circular portions having bearing surfaces for moving the crank arms in opposite relationship to each other. A single shaft with two eccentrics, each respectively in the bearing surfaces turns the two crank arms. The crank arms are in close parallel relationship to each other and close proximity to the hammerbank and counterbalance. The single shaft is connected to a motor for driving the hammerbank and counterbalance, and is formed with a stator having coils with a magnetic ring formed as a rotor portion surrounding the stator, and a flywheel surrounding and connected to the magnetic rotor ring.

Abstract: A dot-matrix line printer includes a printing shuttle which moves reciprocally to carry out a printing operation, and a balancing shuttle which moves in a direction opposite to the direction of the movement of the printing shuttle. The balancing shuttle is partly inserted in the printing shuttle so as not to interfere with the latter upon printing and so that the center of gravity of the balancing shuttle is located as close to the center of gravity of the printing shuttle as possible.

Abstract: An ink jet recording apparatus for recording onto a recording medium by discharging ink includes a recorder for recording on the recording medium by discharging the ink through discharge ports, a setting device for setting a line recording mode in which recording is performed for every line or a page recording mode in which the recording is performed over a plurality of lines, with the recorder, and a controller, which, when the line recording mode is set, moves the discharging port face of the recorder outside of a conveyance passage for the recording medium for every termination of recording of one line, and which, when the page recording mode is set, reciprocates the recorder in the conveyance passage to record over a predetermined area, and after termination of recording of the predetermined area, moves the discharging port face of the recorder outside of the conveyance passage, and then conveys the recording medium for discharge from the apparatus.

Abstract: The printing apparatus or the sheet feeding apparatus disclosed here which employs vibration driven actuators as driving sources has a circuit for detecting the characteristics of the actuator during preparatory operation performed previous to the regular operation. Information detected by said circuit is used to control the actuators during the regular operation. As a result, a printing apparatus or a sheet feeding apparatus capable of reducing wasteful or unnecessary operation can be obtained.

Abstract: The present invention is directed to realize a portable, compact, light, thin, inexpensive and fast printer apparatus. A motor is provided between a printing head unit and a stationary frame member to drive the printing head unit relative to the stationary frame member in leftward and rightward directions, thereby eliminating conventional indirect driving components such as a stepping motor and a lead screw. Further, a sensor is provided in the printing head unit to detect a moving velocity and a position of the printing head unit to thereby construct the printer apparatus having reduced number of components to ensure stable driving and high accuracy. According to such a construction, the motor is integrated into the printing head unit, which self-moves in the printer apparatus to eliminate a mechanism converting a rotational movement into a linear movement, thereby achieving cost down of the printing apparatus.

Abstract: A printer is provided comprising a carriage on which recording head is mounted. Drive mechanisms for moving carriage in reciprocating motions an encoder having openings provided contiguously in the circumferential direction at fixed intervals, attached thereto, and which rotates as carriage moves. A position detector is provided in proximity to the encoder for detecting the encoder's detection-target unit and generates timing pulses in response thereto. A shielding plate is attached to carriage for blocking the encoder from the position detector at the home position. A processor detects the home position for carriage based upon a timing pulse pause time.

Abstract: The present invention provides a carriage shifting apparatus comprising a drive source, a suspension member suspended to transmit a driving force of the drive source, a carriage connected to the suspension member and reciprocally shiftable by the driving force of the drive source, a tension applying means for applying a tension force to the suspension member, and a weight body attached to the tension applying means via a viscoelastic member.

Abstract: A recording apparatus for performing recording uses a carriage mounted with a recording head moving along a guide shaft. The recording apparatus includes a magnetic linear encoder consisting of a scale element magnetized and a detection unit for detecting magnetized information magnetized to the scale element. Provided also are clicks formed on any one of the detection unit and the carriage and click engaging portions formed in the other one of the detection unit and the carriage. The clicks engage with the click engaging portions, whereby the detection unit is snap-locked to the carriage. This enables the detection unit of the magnetic linear encoder to be readily attached to the carriage and besides, when attached, prevents disorder of the information magnetized to the scale element. Further, even when a position of the carriage shifts corresponding to sheets having different thicknesses, a sliding load of the carriage does not change.

Abstract: The printing apparatus or the sheet feeding apparatus disclosed here which employs vibration driven actuators as driving sources has a circuit for detecting the characteristics of the actuator during preparatory operation performed previous to the regular operation. Information detected by said circuit is used to control the actuators during the regular operation. As a result, a printing apparatus or a sheet feeding apparatus capable of reducing wasteful or unnecessary operation can be obtained.

Abstract: To effectively cool a linear motor used in a shuttle mechanism of a printer and also to increase magnetic flux density used in generating thrust in the linear motor, each magnet used in the linear motor is beveled to form chamfers at corners that confront a coil member and that contact corners of adjacent magnets.

Abstract: A shuttle mechanism of a printer apparatus wherein a balance shuttle unit is arranged on the opposite side of the print head in a print shuttle unit, for instance, on the under side of said print shuttle unit, so that the center of the gravity of the print shuttle unit is made to become close to that of the balance shuttle unit. Common components such as the magnet, yoke, guide member may be employed in both the shuttle units.

Abstract: A carriage driving motor is driven with acceleration during a time period substantially equal to the half period of periodic vibration generated in a carriage in its moving direction when the carriage shifts from a stopped state to a moving state. Subsequently, the carriage driving motor is driven at a constant speed. Thus, the vibration of the carriage is minimized and movement of the carriage at the constant speed is stabilized.

Abstract: A method of controlling a transportation velocity of a printhead carriage of a serial printer is disclosed. The printhead carriage is driven by a motor via a timing belt. First, a characteristic equation, which includes a motor speed, a current applied to said motor, an equivalent disturbance indicating environmental variations affecting said motor speed, is discreted. Thereafter, the equivalent disturbance is estimated using the characteristic equation which has been discreted. A value of the equivalent disturbance is determined and subsequently, a value of the equivalent disturbance compensating level is calculated using a discrete low pass filter. Finally, a current to be applied to said motor is obtained by adding a compensating level of the controller to the level of the equivalent disturbance.

Abstract: Disclosed is a shuttle mechanism of a dot line printer including a printing shuttle unit making a reciprocating motion to perform dot printing and a balance shuttle unit making a motion in a direction opposite to the kinetic motion of the printing shuttle unit. This shuttle mechanism is constructed of a linear motor in which a movable unit for the reciprocating motion and a magnetic circuit are separated. With this construction, the movable unit can be decreased in weight. Therefore, the high-speed reciprocating motion can be made, and high-speed printing is thereby attainable. The balance shuttle unit is disposed under the printing shuttle unit. The apparatus can be thereby made compact.

Abstract: Disclosed is a carriage driving device in which a rack 8 with high rigidity and gear teeth 8a at one side elongated therethrough is fixed on a bottom frame 7c in a frame 7 of a printer 1 so that the rack 8 is arranged parallel with a platen 5, and both a pinion 16 meshed with the gear teeth 8a of the rack 8 and a driving motor 15 for rotating the pinion 16 are arranged on a plate 18 which is rotatably supported around a support shaft 17 in a horizontal direction on the carriage 2. The pinion 16 is biased by a spring 22 so as to constantly mesh with the gear teeth 8a of the rack 8. In the carriage 2, a first contact member 10 slidably contacting on the upper surface of the rack 8 and a second contact member 11 slidably contacting to the side of the rack 8 opposite to the side where the gear teeth 8a are formed, are arranged so that a predetermined positional relationship of the carriage 2 against the platen 5 is maintained.

Abstract: A planar auxiliary supporting member for supporting an elastic member for generating a vibration is arranged. The elastic member contacts a rail-shaped stationary member, and moves along the stationary member. The rigidity of the supporting member is set to be low, so that the elastic member as a stator stably moves along the stationary member.

Abstract: A recording apparatus having a paper feeding device for feeding a printing sheet, a detent mechanism capable of engaging the feed roller so as to determine the feeding pitch at which the paper feeding device feeds the sheet, a ribbon feeding mechanism for feeding an ink ribbon, a driving power source for generating a driving force, a transmission mechanism for transmitting a driving force from the driving power source to one of the paper feeding device and the ribbon feeding mechanism to operate the paper feeding device or the ribbon feeding mechanism, and a changeover mechanism for changing over the transmission effected by the transmission mechanism and also changing over the engagement between the detent mechanism and the paper feeding device in a linked relationship with the changeover of the transmission of the driving force.

Abstract: When a DC motor is restarted, a drive signal for the DC motor serves as a pulse signal. Even when a printer is stopped under a maximum load, the DC motor may be restarted a plurality of times, thus vibrating the DC motor and reducing the degree to which the printer is locked. This makes it possible to easily restart the DC motor.

Abstract: In a recording apparatus employing a magnetic linear encoder that includes a magnetized scale and a magnetic head movable along the scale, in order to enable efficient mounting of the scale on the recording apparatus and to enable tension adjustment of the scale, support members are provided for detachably supporting the scale, as is a device for providing tension during the mounting of the scale on side plates of the recording apparatus. Also, the magnetized portion of the scale is positioned behind the carriage. Further, the magnetic head is provided with dust shield members which are in contact with, but rendered slidable with respect to, the scale.

Abstract: A carriage, preferably carrying a knife for cutting a moving web for attachment of the cut web end to a web winding roll, is driven on a supporting rail along a linear path by means of a driving motor operating a toothed driving belt. The belt is detachably clamped to the carriage by a clamp fixed on the carriage and formed by a support plate having a belt supporting surface thereon and a pressure plate provided with teeth for mating engagement with the belt teeth mounted on the support plate in opposed relation to the support plate surface to define with the surface a slot for reception of the belt. The pressure plate is slidably supported for movement toward and away from the surface and is spring-biased to normally clamp the belt therebetween.

Abstract: A recording apparatus, which is provided with a carriage supporting a recording head or reciprocating along a platen, includes a magnetized scale of a magnetic linear encoder positioned along a moving direction of the carriage, and a magnetic head of the magnetic linear encoder, mounted on the carriage and adapted for reading the magnetized pattern of the scale. The scale is provided with at least two magnetized lines of mutually different pitches of magnetization, for recording position information relating to the recording operation, and position information relating to other functions.

Abstract: A carriage motor control device that uses speed determination means (3) for determining a set speed value (SN12) to be set on the basis of an aimed angle value (SN13A) indicative of an aimed rotation angle, an aimed speed value (SN13B) indicative of an aimed rotation speed and the rotation angle value, speed control means (4) for generating a speed control value (SN7) for making the rotation speed value closer to the set speed value on the basis of a difference between the rotation speed value and the set speed value, angle control means (5) for generating an angle control value (SN8) for making the rotation angle value closer to the aimed angle value on the basis of a difference between the aimed angle value and the rotation angle value, selection means (8) for selecting the speed control value as a motor drive control value when the rotation speed value is larger than a first speed value and selecting the angle control value as the motor drive control value when the rotation speed value is smaller than the