JP2007253365A - Recording apparatus, liquid jetting apparatus, and rotary driving mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase freedom of mounting of a rotational driving mechanism 500 using a vibrator 300. <P>SOLUTION: An inkjet recording apparatus 100 includes a conveying driving roller 132 rotationally driven, and a conveying following roller 134 for bringing a sheet-like recording paper 170 with it while it is pushed on the conveying driving roller 132, and is equipped with a conveying part 130 for conveying the recording paper 170 in the conveying direction, and a recording head 164 for delivering ink toward the recording paper 170 conveyed from the conveying part 130. The inkjet recording apparatus 100 is equipped with a driving disc 136 integrally rotating with the conveying driving roller 132, the vibrator 300 stretching/contracting by applying a periodically changing electrical voltage, periodically transmitting at least a pair of a stretching/contracting movement on a circular face of the driving disc 136 and an opposing roller 521 which comes into contact with the driving disc 136 by opposing the vibrator 300 from the back surface of the driving disc 136 at a position with which the vibrator 300 is brought into contact. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording apparatus, a liquid ejecting apparatus, and a rotational drive mechanism. More specifically, the present invention relates to a liquid ejecting apparatus having a conveyance driving roller that conveys a recording material by rotating, and a rotation driving mechanism that can be used therefor.

  In a liquid ejecting apparatus such as an ink jet recording apparatus, many members are rotationally driven. That is, a feed roller that takes the recording material into the apparatus, a conveyance driving roller that conveys the recording material inside, a discharge roller that sends the recording material after recording to the outside, and a timing belt that reciprocates the liquid ejecting head. Many members such as pulleys to be rotated are driven to rotate. For this reason, it is difficult to reduce the number of parts in the entire liquid ejecting apparatus, regardless of whether a driving source is provided for each member or a member is driven from a single driving source via a transmission mechanism. It also becomes a cause which prevents miniaturization of a liquid ejecting apparatus.

Therefore, it is proposed to use so-called ultrasonic actuators using piezoelectric materials as various rotational drive sources in the liquid ejecting apparatus. Patent Document 1 below discloses a structure of a power transmission device in which the amount of rotation can be accurately controlled by engaging an uneven portion formed on the outer periphery of a rotor with a tip of a vibrating body formed in a protruding shape. Patent Document 2 below discloses a structure of a rotary drive device that drives a vibrating body by contacting the inside of an annular rotating body. According to this structure, it is described that both downsizing and high torque driving can be achieved. Patent Document 3 below discloses a structure of a piezoelectric actuator having a contact portion that is elastically supported so as to be displaced in a specific direction. It is described that the operation of the piezoelectric actuator is stabilized by such a structure.
JP 2004-072993 A JP 2004-166479 A Japanese Patent Laying-Open No. 2005-168075

  The ultrasonic actuator described in each of the above-described documents can be made small enough to be incorporated into a wristwatch, but has a driving force that can realize energy conversion efficiency comparable to that of a living body without a speed reduction mechanism. In addition, it is very lightweight and greatly exceeds the living body in the output / weight ratio. Further, since no magnetic field is generated with the operation, it can be used around precision electronic equipment. Therefore, the use of the ultrasonic actuator as the rotational drive source can advantageously work for the liquid ejecting apparatus.

  However, all of the known rotational drive mechanisms described in the above patent documents are directions in which an ultrasonic actuator using a piezoelectric element is perpendicular to the rotational axis of the driven body to be driven with respect to the driven body. It is limited to the structure that contacts For this reason, when an ultrasonic actuator is mounted on the liquid ejecting apparatus, the layout is limited.

  In some cases, a certain speed reduction mechanism is required for the purpose of adapting the characteristics of the ultrasonic actuator supplied to the market to the specifications required for the driven device. However, the combined use of a general speed reduction mechanism reduces the advantage of using an ultrasonic actuator, so a speed reduction mechanism that takes advantage of the characteristics of the ultrasonic actuator is required.

  Therefore, for the purpose of solving the above-mentioned problems, as a first embodiment of the present invention, a conveyance drive roller that is driven to rotate around a rotation axis that is orthogonal to a predetermined conveyance direction and a conveyance drive roller are attached. A conveyance driven roller that is rotated and pressed while pressing the sheet-like recording material against the conveyance driving roller, and conveys the recording material in the conveyance direction, toward the recording material conveyed by the conveyance unit. A recording head having a recording head that discharges ink to form an image, a drive disk that is coaxially mounted on the transport drive roller and rotates integrally with the transport drive roller, and a periodically changing voltage. An actuator that includes a piezoelectric material plate that expands and contracts by being applied to the actuator, and rotates the drive disc around the rotation axis by contacting the circular surface of the drive disc in at least a part of the expansion and contraction. Actuator Te is in a position to abut, further comprising recording device abutting the facing member from the rear surface opposite to the driving disc to the actuator of the drive disc is provided. Accordingly, a drive mechanism having a desired drive torque can be easily formed using an actuator including a piezoelectric element. Further, both the drive disk and the ultrasonic actuator are thin or small and do not occupy space. Furthermore, due to the unique structure in which the opposing member abuts against the drive disk from the back surface of the actuator, rotational torque is transmitted without generating a bending moment to the drive disk and the transport drive roller that are driven bodies. be able to. Accordingly, it is possible to cope with the precise rotation control required in the transport unit or the like of the liquid ejecting apparatus.

  According to one embodiment, in the recording apparatus, each of the actuators is driven and driven by a longitudinal vibration element that periodically expands and contracts in a direction including a circumferential component of the drive disk, and the longitudinal vibration element. And a contact member that periodically transmits at least a part of the expansion and contraction motion to the disk. Thereby, since a drive disc is driven with a short period, precise rotation control can be performed.

  According to another embodiment, in the recording apparatus, each of the actuators includes a flexural vibration element that periodically expands and contracts at a phase different from that of the longitudinal vibration element that displaces the contact portion in parallel with the surface of the drive disk. In addition, the contact portion is simultaneously driven by the longitudinal vibration element and the bending vibration element, and is displaced on a trajectory forming a circle or an ellipse on a plane perpendicular to the surface of the drive disk. As a result, the contact portion of the actuator does not simply contact but also pushes the drive disc in the direction to be driven, so that the drive disc can be rotationally driven with high efficiency.

  In any of the embodiments, in the recording apparatus, each of the actuators is urged in a direction approaching the drive disk with respect to the expansion / contraction direction of the longitudinal vibration element. Thereby, the contact of the actuator with the drive disk is maintained, and the drive disk can be efficiently rotated. In addition, even when the actuator stops operating, the actuator itself abuts against the drive disk and brakes, so that precise rotation control can be performed.

  According to another embodiment, in the recording apparatus, each of the opposing members is urged toward the drive disk with a force having a magnitude that balances with the force applied by the contact portion to the drive disk. As a result, the force by which the actuator pushes the drive disk and the force by which the opposing member pushes the drive disk cancel each other, and only the rotational drive force is transmitted to the drive disk and the conveyance drive roller. Therefore, the conveyance drive roller can be efficiently rotated.

  According to another embodiment, in the recording apparatus, each of the facing members can be a sliding facing member that slides in contact with the driving disk on the back surface of the actuator with respect to the driving disk. Thereby, the opposing member can be formed with a very simple structure.

  According to another embodiment, in the recording apparatus, each of the facing members can be a facing roller that is brought into contact with the driving disk and rotated along with the driving disk. As a result, the resistance caused by the contact of the opposing member hardly occurs with respect to the rotation of the drive disk, and therefore the drive disk can be smoothly rotated.

  According to another embodiment, in the recording apparatus, the opposing member and the actuator are connected via the subframe to form an actuator assembly. Accordingly, since the main part of the drive mechanism can be supplied as an assembly including the opposing member and the actuator, a recording apparatus using the actuator can be manufactured with high productivity.

  According to another embodiment, in the recording apparatus, the actuator assembly is displaced in a direction parallel to the rotation axis to balance the force applied to the drive disk by the actuator and the opposing member. As a result, even when the recording apparatus is formed using the actuator assembly, no stress other than the driving direction is generated on the driving disk, so that the transport driving roller can be efficiently rotated.

  Further, as a second embodiment of the present invention, a sheet-like recording material that is urged toward the conveyance driving roller that is driven to rotate around a rotation axis that is orthogonal to a predetermined conveyance direction. A transport driven roller that is rotated while being pressed against the transport drive roller, and transports the recording material in the transport direction, and a liquid jet that sprays and adheres the liquid toward the recording material transported by the transport unit A liquid ejecting apparatus including a head, a drive disk that is coaxially mounted on a transport drive roller and rotates integrally with the transport drive roller, and a piezoelectric material plate that expands and contracts by applying a periodically changing voltage. An actuator that abuts against the circular surface of the drive disc at least in part of the expansion and contraction motion and rotates the drive disc around the rotation axis, and a position where the actuator abuts against the drive disc. Te, further comprising a liquid ejecting apparatus that contacts opposing member from the rear surface opposite to the driving disc to the actuator of the drive disc is provided. Thereby, the above-described effect can be enjoyed also in the liquid ejecting apparatus.

  Furthermore, as a third embodiment of the present invention, there is provided a rotational drive mechanism for rotationally driving a rotating body around a rotational axis, a drive disk that is coaxially mounted on the rotating body and rotates integrally with the rotating body, and a cycle An actuator that includes a piezoelectric material plate that is expanded and contracted by applying a voltage that changes in a moving manner, and that abuts against the circular surface of the drive disk at least in part of the expansion and contraction, and rotates the drive disc around the rotation axis; A drive mechanism comprising: a counter member that contacts the drive disk from the back surface of the drive disk at a position where the actuator contacts the disk. Thereby, the above-mentioned effect can be enjoyed in many apparatuses using the rotational drive mechanism.

  Further, as a fourth embodiment of the present invention, a sheet-like recording material that is urged toward a conveyance driving roller that is rotationally driven around a rotation axis that is orthogonal to a predetermined conveyance direction and that is urged toward the conveyance driving roller. A transporting roller that includes a transport driven roller that is rotated while being pressed against the transport driving roller, and a liquid ejecting unit that transports the recording material in the transporting direction and discharges and adheres the liquid toward the recording material transported by the transporting unit. A liquid ejecting apparatus including a head, a drive disk that is coaxially mounted on a transport drive roller and rotates integrally with the transport drive roller, and a piezoelectric material plate that expands and contracts by applying a periodically changing voltage. An actuator that abuts against the circular surface of the drive disc in at least a part of the expansion and contraction motion and rotates the drive disc around the rotation axis, and the actuator abuts against the drive disc A liquid ejecting apparatus that is arranged opposite member in the position to counteract the resulting bending stresses on the transport driving roller case is provided. Accordingly, the above-described effects can be enjoyed in many liquid ejecting apparatuses having various layouts.

  Furthermore, as a fifth aspect of the present invention, there is provided a rotational drive mechanism for rotationally driving the rotating body, a drive disk that is coaxially mounted on the rotating body and rotates integrally with the rotating body, and changes periodically. It includes a piezoelectric material plate that expands and contracts when a voltage is applied, and includes an actuator that abuts against the circular surface of the drive disk at least in part of the expansion and contraction, and rotates the drive disk around the rotation axis. Provided is a rotation drive mechanism in which opposing members are arranged so as to cancel out bending stresses generated in a rotating body by abutting against a disc. Thereby, the above-mentioned effect can be enjoyed in many devices using a rotational drive mechanism.

  Note that the summary of the invention described above does not enumerate all necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a perspective view showing an internal structure of a mechanism formed on a lower case 110 by removing an upper case of an ink jet recording apparatus 100 according to one embodiment. As shown in the drawing, a paper feeding unit 120 stands up behind the ink jet recording apparatus 100. The paper feeding unit 120 includes a paper support 122 that supports the recording paper 170 from the rear, and a side support 124 and a slide support 126 that position side edges of the recording paper 170 on both sides of the paper support 122. Here, the side support 124 is fixed to a side end portion of the paper support 122. On the other hand, the slide support 126 can be slid and moved on the paper support 122 and is in close contact with the side edge of the recording paper 170 even when the recording paper 170 having a different width is loaded. Although not shown in the drawing, a feeding unit is provided in the vicinity of the lower end of the paper support 122 for taking the recording paper 170 loaded on the paper support 122 into the ink jet recording apparatus 100 one by one.

  On the other hand, an internal mechanism supported by the frame 112 is formed on the lower case 110. That is, the frame 112 stands upright substantially over the entire width of the lower case 110 and supports the carriage 160 on the front surface thereof. The carriage 160 can move horizontally along the guide portion 116 that is a part of the frame 112. A timing belt 146 stretched between a pair of pulleys 148 is disposed between the carriage 160 and the frame 112, and a part of the timing belt 146 is coupled to the carriage 160. In addition, since at least one of the pulleys 148 is driven to rotate, the timing belt 146 travels horizontally between the pulleys 148. Therefore, the carriage 160 reciprocates horizontally as the timing belt 146 travels.

  The carriage 160 is loaded with an ink cartridge 162 containing ink, and suspends the recording head 164 on the bottom surface thereof. Accordingly, ink can be discharged downward while reciprocating along the guide portion 116. Further, a platen 140 is disposed below the reciprocating range of the carriage 160. The platen 140 supports a recording sheet 170 conveyed by a conveyance unit 130 and a discharge unit 150, which will be described later, from below, and maintains a predetermined distance from the recording head 164. Therefore, the recording head 164 can form an image at an accurate position on the recording paper 170 on the platen 140.

  A transport unit 130 is disposed behind the platen 140 and a discharge unit 150 is disposed in front of the platen 140. The conveyance unit 130 includes a conveyance driving roller 132 that is rotationally driven, and a conveyance driven roller 134 that is rotated by the conveyance driving roller 132. The discharge unit 150 also includes a discharge drive roller 152 that is rotationally driven and a discharge driven roller 154 that is rotated along with the discharge drive roller 152. In FIG. 1, the discharge driven roller 154 supported by the discharge unit frame 155 can be seen.

  The frame 112 extends forward at both ends thereof to form a frame side portion 114. The frame side portion 114 supports the conveyance driving roller 132 and the like, and also supplements the rigidity of the frame 112 itself. Further, a home position including a cap member 166 and the like is formed on the side portion of the platen 140. When the ink jet recording apparatus 100 is not operating, the carriage 160 moves to the home position, and the recording head 164 is covered with the cap member 166. This prevents clogging of the recording head 164 due to ink drying. Further, a control circuit 190 is mounted on the back surface of the frame 112. The control circuit 190 controls the operation of each unit of the ink jet recording apparatus 100 and also controls input / output of signals from / to the outside.

  FIG. 2 is a diagram showing a conveyance path 200 of the recording paper 170 in the ink jet recording apparatus 100 shown in FIG. In FIG. 2, the same reference numerals are assigned to the same components as those in FIG.

  As shown in the figure, the recording paper 170 taken into the inside from the paper feeding unit 120 is first sandwiched between the conveyance driving roller 132 and the conveyance driven roller 134 in the conveyance unit 130. In the conveyance unit 130, as will be described later, the conveyance drive roller 132 is rotationally driven. Further, the transport driven roller 134 is urged toward the transport driving roller 132. Therefore, the recording paper 170 sandwiched between the transport driving roller 132 and the transport driven roller 134 is pressed against the rotating transport driving roller 132, moves according to the rotation, and is fed onto the platen 140.

  The front end of the recording paper 170 that has passed over the platen 140 eventually reaches the discharge unit 150 and is sandwiched between the discharge drive roller 152 and the discharge driven roller 154. Again, the discharge drive roller 152 is driven to rotate, and the discharge driven roller 154 is urged toward the discharge drive roller 152 and is rotated along with the discharge drive roller 152. Accordingly, the recording paper 170 sandwiched between the discharge drive roller 152 and the discharge driven roller 154 moves according to the rotation of the discharge drive roller 152 and is finally sent out of the ink jet recording apparatus 100.

  As described above, in the ink jet recording apparatus 100, the recording paper 170 is transported in the transport direction from the paper feeding unit 120 to the discharge unit 150. Therefore, the recording head 164 can form an image by ejecting ink to a desired area on the surface of the recording paper 170 by appropriately combining the reciprocating movement of the carriage 160 and the conveyance of the recording paper 170 to the above-described conveyance.

  The transport drive roller 132 is driven by an actuator 400 described later via a drive disk 136 attached to the end of the transport drive roller 132. That is, the drive disk 136 is a disk-shaped member that is coaxial with the transport drive roller 132 and is mounted on the transport drive roller 132 to rotate integrally. Since the effective diameter of the drive disk 136, that is, the position where the actuator 400 abuts on the drive disk 136 and can be driven can be arbitrarily selected, a rotation drive mechanism that can obtain the drive torque required for the transport drive roller 132 can be easily formed. it can.

  In FIG. 2, a counter member 520 described later is disposed near the lower end of the drive disk 136. The actuator 400 that rotationally drives the drive disk 136 is in contact with the drive disk 136 on the back surface of the opposed roller 521 of the opposed member 520 with respect to the drive disk 136. Although not shown, the transport drive roller 132 is equipped with an encoder scale that rotates integrally. On the other hand, an encoder sensor is disposed on the frame side portion 114, and the rotation amount or rotation speed of the conveyance drive roller 132 can be detected with high accuracy. Therefore, the function mounted on the control circuit 190 can perform feedback control of the operation amount, the operation speed, and the like of the actuator 400 to perform highly accurate conveyance control.

  On the other hand, the discharge drive roller 152 is rotationally driven via a relay gear 180 and a drive gear 156 from a gear portion 137 formed on the outer periphery of the drive disk 136. The relay gear 180 includes a large-diameter gear 182 that meshes with the gear portion 137 of the drive disk 136 and a small-diameter gear 184 that meshes with the drive gear 156. Although the number of teeth of the large-diameter gear 182 is smaller than that of the drive disk 136 and the gear portion 137, the drive gear 156 has a larger number of teeth than the small-diameter gear 184, and the drive gear 156 is larger in diameter than the discharge drive roller 152. The conveyance drive roller 132 and the discharge drive roller 152 move the recording paper 170 at substantially the same speed.

  In the ink jet recording apparatus 100 that performs the operation as described above, the conveyance drive roller 132 is rotationally driven by the vibrator 300 via the drive disk 136. That is, the vibrator 300 is included in the actuator 400 lifted from the lower case 110 via the spacer 412, and a contact portion 318 described later drives near the outer periphery of the drive disk 136 in the circumferential direction of the drive disk 136. To do.

  FIG. 3 is an exploded perspective view showing the structure of the vibrator 300 loaded on the pedestal 410 in the actuator 400. As shown in the figure, the vibrator 300 is formed by fixing a reinforcing plate 310 and a pair of piezoelectric elements 320 that sandwich the reinforcing plate 310 together to a base plate 330 with screws 340.

  The reinforcing plate 310 is a single metal plate formed in the illustrated shape, and has a rectangular reinforcing portion 312 having substantially the same shape and dimensions as the piezoelectric element 320, and a contact protruding from one of the short sides of the reinforcing portion 312. Part 318. Further, from substantially the center of each long side of the reinforcing portion 312, a pair of arm portions 314 extending outward from the reinforcing portion 312, and a round hole 316 formed at the tip of each of the arm portions 314, and A long hole 317 is provided.

  Each of the piezoelectric elements 320 includes a piezoelectric material plate 322 having substantially the same shape and dimensions as the reinforcing portion 312, a common electrode 329 formed over one surface of the piezoelectric material plate 322, and the other of the piezoelectric material plates 322. A central electrode 324 and side electrodes 321, 233, 235, and 237 formed by dividing the surface are provided. Here, the center electrode 324 is formed over the entire length of the piezoelectric material plate 322 in the longitudinal direction. Further, the center electrode 324 is arranged at the center in the short side direction of the piezoelectric material plate 322. On the other hand, the side electrodes 321, 323, 325, and 327 are formed along the long sides of the piezoelectric material plate 322, respectively. In other words, the side electrodes 321, 323, 325, and 327 are all formed so as to be biased laterally in the short side direction of the piezoelectric material plate 322. The central electrode 324 and the side electrodes 321, 233, 235, and 237 are formed separately from each other and are electrically independent. Therefore, when a voltage is applied between the common electrode 329 and one of the electrodes, the piezoelectric material plate 322 in the region occupied by the electrode expands or contracts.

  The piezoelectric element 320 formed as described above is bonded and integrated with the reinforcing plate 310 over the entire surface. Therefore, when the piezoelectric element 320 is deformed, the reinforcing plate 310 is also deformed integrally. On the other hand, the reinforcing plate 310 integrated with the piezoelectric element 320 is fixed to the base plate 330 by a screw 340 inserted through a round hole 316 and a long hole 317 at the tip of the arm portion 314.

  Here, after the round hole 316 is screwed first, the screw 340 inserted through the elongated hole 317 is fastened, whereby the reinforcing plate 310 can be fixed without applying stress. In addition, the region where the screw hole 332 is formed in the base plate 330 is formed thicker than the central portion by the step 338. Therefore, even in a state of being fixed to the base plate 330, the piezoelectric element 320 is floating from the base plate 330 and can be freely deformed.

  In the base plate 330, a pair of elongated holes 331 and 336 formed in the same direction are formed in a thin portion sandwiched between the steps 338. The base plate 330 is positioned on a pedestal 410 (to be described later) by screws inserted through the long holes 331 and 336. Therefore, even after the positioning, the longitudinal direction of the long holes 331 and 336 can be displaced.

  FIG. 4 is a diagram for explaining the operation when a periodically changing voltage is applied between the common electrode 329 and the central electrode 324 of the piezoelectric element 320 shown in FIG. As shown in the figure, when a voltage is applied via a central electrode 324 disposed at the center of the piezoelectric material plate 322, the piezoelectric element 320 vibrates so that its length in the longitudinal direction changes. Accordingly, the contact portion 318 of the reinforcing plate 310 also vibrates with an amplitude parallel to the longitudinal direction of the piezoelectric material plate 322 (hereinafter, vibration generated by the voltage applied to the central electrode 324 is referred to as “longitudinal vibration”).

  FIG. 5 is a diagram for explaining the operation when a periodically changing voltage is applied to the side electrodes 321, 323, 325, and 327 of the piezoelectric element 320 shown in FIG. 3. Here, of the four side electrodes 321, 323, 325, and 327, the side electrodes 321 and 325 and the side electrodes 323 and 327 that are located diagonally to each other are used as electrode pairs, and the electrodes that form each electrode pair A voltage that changes with the period of the same phase is applied between the common electrode 329 and a voltage that changes with the period of the opposite phase between the common electrode 329 and the electrode pair. As described above, since the side electrodes 321, 323, 325, and 327 are disposed at positions deviated from the center of the piezoelectric material plate 322, the piezoelectric material plate 322 undulates as a result of each electrode extending or contracting. Bend like so. As a result, the contact portion 318 of the reinforcing plate 310 vibrates with an amplitude parallel to the short side of the piezoelectric material plate 322 (hereinafter referred to as “bending” caused by the voltage applied to the side electrodes 321, 233, 235, 237). Vibration ”).

  FIG. 6 is a diagram showing the displacement of the contact portion 318 when the longitudinal vibration and the bending vibration are generated simultaneously. As shown in the drawing, by appropriately setting the phase difference and the amplitude difference between the longitudinal vibration and the bending vibration, the contact portion 318 rotates in a substantially elliptical orbit. Thereby, the frictional force is not applied to the object to be contacted because the frictional force is increased by increasing the pressure in the driving direction and is separated in the counter-driving direction. Therefore, by bringing the contact portion 318 into contact with another member, for example, the drive disk 136 shown in FIG. 2, in a partial section on the elliptical orbit, it can be driven in a specific direction. Moreover, a desired driving force and driving speed can be selected by changing the shape of the elliptical orbit. Note that it is the portion between the arm portion 314 and the contact portion 318 in the reinforcing plate 310 that directly contributes to the drive of the drive disk 136 in the vibrator 300. However, by operating the side opposite to the contact part 318 symmetrically with respect to the arm part 314, the moments of inertia on both sides of the arm part 314 cancel each other, and a quiet and high-speed operation can be realized.

  Here, as the frequency of the voltage applied to the piezoelectric element 320, a frequency between the resonance frequencies of longitudinal vibration and bending vibration is appropriately selected. The voltage waveform is not particularly limited, and for example, a sine wave, a rectangular wave, a trapezoidal wave, a sawtooth wave, or the like can be employed.

  The characteristics of the piezoelectric element 320 vary depending on the size and shape of the piezoelectric material plate 322 and the division form of each electrode. That is, in the piezoelectric element 320, it is preferable that the resonance frequencies of longitudinal vibration and bending vibration are close to each other, and more specifically, the difference between the resonance frequencies is preferably 3% or less. If the difference between the resonance frequencies of both vibrations is greater than 3%, the resonance point of the longitudinal vibration and the resonance point of the bending vibration are greatly separated, and it becomes difficult to set a vibration frequency at which the amplitudes of both vibrations increase simultaneously.

  The composition of the piezoelectric material plate 322 is not particularly limited, and lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, zinc niobate Preferred examples include lead and lead scandium niobate. Moreover, the material of each electrode can be formed by nickel, gold, or the like by a method such as plating, sputtering, vapor deposition, or thick film printing. Further, as a material of the reinforcing plate 310, phosphor bronze can be preferably exemplified.

  FIG. 7 is a plan view showing the structure of the actuator 400 including the vibrator 300 having the structure and function as described above. As shown in the figure, the actuator 400 includes the vibrator 300 and a pedestal 410 fixed to the spacer 412 while elastically supporting the vibrator 300.

  As described above, the base plate 330 can be displaced in the longitudinal direction of the long holes 331 and 336 by positioning with screws (not shown) inserted into the long holes 331 and 336. However, on the base 410, the base plate 330 is biased toward the contact portion 318 side of the vibrator 300 by the spring 446 inserted between the spring guide 442 on the base 410 side and the spring guide 334 on the base plate 330 side. Is done. Note that the spring guides 442 and 334 also abut when the vibrator 300 is largely retracted, and also serve as a bump stop that prevents extreme displacement. The spring guide 442 is fixed to the pedestal 410 by a locking piece 440 fixed by a screw 444.

  The pedestal 410 includes a pair of terminals 430. Each terminal 430 has a pair of terminals and is coupled to the electrodes of the piezoelectric element 320 by lead wires (not shown). Thereby, a favorable electrical connection with the outside can be obtained for the elastically supported vibrator 300. Further, the pedestal 410 has screw holes at its four corners and can be fixed to other members by screws 420. Therefore, mounting on the spacer 412 and the like is facilitated.

  By supplying the actuator 400 including the pedestal 410 as described above, the elastically supported vibrator 300 can be easily mounted and a good contact state with respect to the driven body can be obtained. In addition, by using the mounting screw holes of the base 410, the vibrator 300 itself can be easily mounted and electrically connected.

  FIG. 8 is a cross-sectional view of the drive mechanism 500 formed by combining the drive disk 136, the vibrator 300, and the opposing member 520 as viewed from the radial direction of the drive disk 136. FIG. 9 is a perspective view depicting the same drive mechanism 500 in three dimensions.

  As shown in these drawings, the conveyance driving roller 132 is supported by the frame side portion 114 of the ink jet recording apparatus 100, and a driving disk 136 is mounted in the vicinity of the end portion thereof. The drive disk 136 is attached to the conveyance drive roller 132 outside the frame side portion 114. An ultrasonic actuator assembly 510 in which the vibrator 300 is mounted on the spacer 512 is disposed on the lower case 110 immediately below the frame side portion 114. The contact portion 318 of the vibrator 300 contacts the drive disk 136 from the side to rotate the drive disk 136.

  On the other hand, the facing member 520 is disposed on the opposite side of the ultrasonic actuator assembly 510 with the drive disk 136 interposed therebetween. The opposing member 520 includes an arm 526 that extends upward via a hinge 524 and an opposing roller 521 that is horizontally supported on the upper end of the arm 526 on the upper surface of a base 522 disposed on the lower case 110. Further, a spring 528 having one end suspended from the arm 526 directly below the opposing roller 521 and the other end coupled to the pedestal 522 is provided. The spring 528 is biased in a direction in which the arm 526 is tilted toward the drive 136 by shortening its length.

  Accordingly, the facing roller 521 is pressed toward the drive disk 136. The opposed roller 521 that is pressed pushes the drive disk 136 from the side on the back surface at a position where the contact portion 318 of the vibrator 300 contacts the drive disk 136. The counter roller 521 is pivotally supported by the arm 526 and is rotated along with the rotation of the drive disk 136. Therefore, the load for driving the drive disk 136 does not increase when the facing roller 521 is pressed.

  It should be noted that the magnitude of the force with which the opposing roller 521 pushes the drive disk 136 is preferably set so as to cancel the force with which the vibrator 300 pushes the drive disk 136 when driven. This prevents a force that causes displacement in the direction of the rotation axis from acting on the drive disk 136.

  In the drive mechanism 500 as described above, the drive disk 136 is rotationally driven by the vibrator 300 while being pressed by the opposing roller 521 from the outside, so that it is displaced in the axial direction despite being driven from the side surface. There is no. Therefore, a bending moment with respect to the transport driving roller 132 does not occur. Further, since the vibrator 300 drives the drive disk 136 pushed from the back surface by the facing member 520, the drive force can be transmitted efficiently.

  FIG. 10 is a view showing another structure of the drive mechanism 500. As shown in FIG. It is similar to the drive mechanism 500 shown in FIGS. 8 and 9 in that the opposed roller 521 is disposed outside the drive disk 136. However, in this drive mechanism 500, the opposed roller 521 is fixed. Yes. On the other hand, in the ultrasonic actuator assembly 530 that drives the drive disk 136 from the frame side portion 114 side, the actuator 400 shown in FIG. As already described, since the actuator 400 elastically supports the vibrator 300, the same function as that of the drive mechanism 500 shown in FIG. 8 is formed.

  FIG. 11 is a view showing still another structure of the drive mechanism 500. As shown in the figure, the drive mechanism 500 has a function equivalent to that of the drive mechanism 500 shown in FIG. However, in this drive mechanism 500, the spacer 532 is formed integrally with a pedestal that supports the counter roller 521 to form an ultrasonic actuator assembly 550 equipped with the actuator 400 and the counter roller 521. Such an ultrasonic actuator assembly 550 integrally includes members excluding the drive disk 136 among members forming the drive mechanism 500. Therefore, by supplying such an ultrasonic actuator assembly 550 alone, the drive mechanism 500 can be assembled with fewer man-hours.

  12 and 13 are a cross-sectional view and a perspective view showing still another structure of the drive mechanism 500. FIG. As shown in the figure, the drive mechanism 500 mounts the ultrasonic actuator assembly 550 shown in FIG. 11 on the lower case 110 via the guide rail 552. As shown in FIG. 13, the ultrasonic actuator assembly 550 on the guide rail 552 can slide in a direction parallel to the rotation axis of the transport driving roller 132. Therefore, even if the drive disk 136 is displaced for some reason or deformed, the ultrasonic actuator assembly 550 is also displaced following the displacement, so that only the driving force for driving the drive disk 136 is transmitted and the conveyance drive is performed. No bending moment is generated on the roller 132 side. Therefore, the load on the actuator 400 is also stable and can be rotated smoothly and accurately.

  FIG. 14 is a perspective view schematically showing another layout of the drive mechanism 500 in which the drive disk 136 and the actuator 400 are combined. As shown in the figure, the drive mechanism 500 includes an actuator assembly 530 and an opposing member 520 that abut against the same surface of the drive disk 136. Here, the contact portion 318 of the actuator assembly 530 and the facing roller 521 of the facing member 520 are in contact with the drive disk 136 at positions symmetrical to the axis of the transport drive roller 132.

  FIG. 15 is a cross-sectional view of the drive mechanism 500 shown in FIG. 14 cut along a plane including the rotation shaft of the transport drive roller 132. As shown in the figure, in the ink jet recording apparatus 100, the actuator assembly 530 is fixed on the lower case 110. Further, the facing member 520 is supported by a part of the frame side portion 114. As described above, the actuator assembly 530 and the facing member 520 are in contact with the drive disk 136 in the same direction at positions symmetrical to the transport drive roller 132. Therefore, as indicated by the arrows in the figure, the forces applied by the actuator assembly 530 and the opposing member 520 in the axial direction of the transport drive roller 132 cancel each other in the drive disk 136, and a bending moment M is applied to the transport drive roller 132. Does not occur.

  As described above, the drive mechanism 500 using the combination of the vibrator 300 and the drive disk 136 can easily form the drive mechanism 500 having a desired drive torque. Further, both the drive disk 136 and the vibrator 300 are thin or small and do not occupy a space. Further, a unique layout combining the vibrator 300 or the actuator 400 with the opposing member 520, the opposing roller 521, and the like can transmit rotational torque without generating a bending moment to the transport driving roller 132 that is a driven body. Can do. Accordingly, it is possible to respond to the precise rotation control required in the transport unit 130 of the ink jet recording apparatus 100 or the like.

  In the embodiment described above, the rotation of the drive disk 136 is not hindered by contacting or pressing the rotating counter roller 521 against the drive disk 136. However, if a member having a sufficiently low coefficient of friction is used, the facing roller 521 can be replaced with a contact member that contacts and slides without rotating. In this case, the structure of the facing member 520 becomes simpler, and the manufacturing cost can be reduced.

  In the above embodiment, the ink jet recording apparatus 100 has been described as an example of the liquid ejecting apparatus, but the embodiment is not limited thereto. That is, examples of other liquid ejecting apparatuses include a color filter manufacturing apparatus including a color material ejecting head, an organic EL display, an electrode forming apparatus used for manufacturing an FED (surface emitting display), a biochip manufacturing apparatus, and the like.

  Furthermore, although the present invention has been described using the embodiment, the technical scope of the present invention is not limited to the scope described in the embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 is a perspective view showing a structure of an ink jet recording apparatus 100 according to one embodiment. FIG. 2 is a schematic cross-sectional view showing a conveyance path 200 of a recording paper 170 in the ink jet recording apparatus 100 shown in FIG. 4 is an exploded perspective view showing a structure of a vibrator 300. FIG. 6 is a diagram for explaining a longitudinal vibration operation of a vibrator 300. FIG. FIG. 10 is a diagram illustrating a bending vibration operation of a vibrator 300. FIG. 6 is a diagram showing a locus of displacement of a contact portion 318 of a vibrator 300. 5 is a plan view showing a structure of an actuator 400 that elastically supports a vibrator 300 with respect to a base 410. FIG. 4 is a cross-sectional view showing a layout of a drive mechanism 500 in which a drive disk 136 and a vibrator 300 are combined, taken along a plane including a rotation axis of a conveyance drive roller 132. FIG. It is a perspective view which shows typically the layout of the drive mechanism 500 shown in FIG. FIG. 5 is a cross-sectional view showing a layout of a drive mechanism 500 in which a drive disk 136 and an actuator 400 are combined, taken along a plane including a rotation axis of a conveyance drive roller 132. FIG. 10 is a cross-sectional view showing another layout of the drive mechanism 500 cut along a plane including the rotation axis of the conveyance drive roller 132. FIG. 6 is a cross-sectional view showing another layout of a drive mechanism 500 in which a drive disk 136 and an actuator 400 are combined, taken along a plane including the rotation axis of the conveyance drive roller 132. It is a perspective view which shows typically the layout of the drive mechanism 500 shown in FIG. FIG. 10 is a perspective view schematically showing another layout of a drive mechanism 500 in which a drive disk 136 and an actuator 400 are combined. FIG. 15 is a cross-sectional view showing the drive mechanism 500 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Inkjet recording device, 110 Lower case, 112 frame, 114 frame side part, 116 Guide part, 120 Paper feed part, 122 Paper support, 124 Side support, 126 Slide support, 130 Conveyance part, 132 Conveyance drive roller, 134 Conveyance driven Roller, 136 driving disk, 137 gear section, 140 platen, 146 timing belt, 148 pulley, 150 discharge section, 152 discharge drive roller, 154 discharge driven roller, 155 discharge section frame, 156 drive gear, 160 carriage, 162 ink cartridge, 164 recording head, 170 recording paper, 180 relay gear, 182 large diameter gear, 184 small diameter gear, 200 transport path, 300 vibrator, 310 reinforcing plate, 312 reinforcing section, 314 arm section, 16 Round hole, 317, 331, 336 Long hole, 318 Contact part, 320 Piezo element, 322 Piezoelectric material plate, 321, 323, 325, 327 Side electrode, 324 Central electrode, 329 Common electrode, 330 Base plate, 332 Screw Hole, 334, 442 Spring guide, 338 Step, 340, 420, 444 Screw, 400 Actuator, 410, 522 Base, 412, 532 Spacer, 430 Terminal, 440 Locking piece, 446, 528 Spring, 500 Drive mechanism, 510, 530, 550 Actuator assembly, 512 Spacer, 520 Opposing member, 521 Opposing roller, 524 Hinge, 526 Arm, 552 Guide rail

Claims (13)

A conveyance drive roller that is driven to rotate around a rotation axis that is orthogonal to a predetermined conveyance direction, and a sheet-like recording material that is urged toward the conveyance drive roller and is pressed against the conveyance drive roller. A conveyance unit that conveys the recording material in the conveyance direction;
A recording apparatus comprising: a recording head that forms an image by discharging ink toward the recording material conveyed by the conveying unit;
A drive disk that is coaxially mounted on the transport drive roller and rotates integrally with the transport drive roller;
A piezoelectric material plate that expands and contracts by applying a periodically changing voltage, and contacts the circular surface of the drive disc in at least a part of the expansion and contraction, and the drive disc is rotated around the rotation axis. An actuator to rotate;
A recording apparatus further comprising: an opposing member that contacts the drive disk from a back surface of the drive disk at a position where the actuator contacts the drive disk.   Each of the actuators is a longitudinal vibration element that periodically expands and contracts in a direction including a circumferential component of the drive disk, and at least a part of the expansion and contraction motion is driven by the longitudinal vibration element to the drive disk. The recording apparatus according to claim 1, wherein the abutting member is transmitted periodically. Each of the actuators further comprises a bending vibration element that periodically expands and contracts at a phase different from that of the longitudinal vibration element, displacing the contact portion in parallel with the surface of the drive disk.
The contact portion is simultaneously driven by the longitudinal vibration element and the bending vibration element to be displaced on a trajectory forming a circle or an ellipse on a plane perpendicular to the surface of the drive disk. Recording device.   4. The recording apparatus according to claim 2, wherein each of the actuators is biased in a direction approaching the drive disk with respect to an expansion / contraction direction of the longitudinal vibration element.   5. The device according to claim 2, wherein each of the facing members is urged toward the drive disk with a force that balances with the force applied by the contact portion to the drive disk. The recording device according to item.   6. The sliding member according to claim 1, wherein each of the facing members is a sliding facing member that slides in contact with the driving disk on a back surface of the actuator with respect to the driving disk. Recording device.   6. The recording apparatus according to claim 1, wherein each of the facing members is a facing roller that is brought into contact with the drive disk and is rotated by the drive disk.   The recording apparatus according to claim 1, wherein the opposing member and the actuator are connected via a subframe to form an actuator assembly.   The recording apparatus according to claim 8, wherein the actuator assembly is displaced in a direction parallel to the rotation axis to balance the force applied to the drive disk by the actuator and the opposing member. A conveyance drive roller that is driven to rotate around a rotation axis that is orthogonal to a predetermined conveyance direction, and a sheet-like recording material that is urged toward the conveyance drive roller and is pressed against the conveyance drive roller. A conveyance unit that conveys the recording material in the conveyance direction;
A liquid ejecting apparatus comprising: a liquid ejecting head that ejects and adheres liquid toward the recording material transported by the transporting unit;
A drive disk that is coaxially mounted on the transport drive roller and rotates integrally with the transport drive roller;
A piezoelectric material plate that expands and contracts by applying a periodically changing voltage is included, and at least a part of the expansion and contraction motion contacts the circular surface of the drive disc and rotates the drive disc around the rotation axis. An actuator to be
A liquid ejecting apparatus, further comprising: a facing member that is opposed to the actuator from the back surface of the driving disk at a position where the actuator is in contact with the driving disk. A rotary drive mechanism for driving a rotary body to rotate around a rotation axis,
A drive disk that is coaxially mounted on the rotating body and rotates integrally with the rotating body;
A piezoelectric material plate that expands and contracts by applying a periodically changing voltage is included, and at least a part of the expansion and contraction motion contacts the circular surface of the drive disc and rotates the drive disc around the rotation axis. An actuator to be
A drive mechanism comprising: a counter member that contacts the drive disk from the back surface of the drive disk at a position where the actuator contacts the drive disk. A conveyance drive roller that is driven to rotate around a rotation axis that is orthogonal to a predetermined conveyance direction, and a sheet-like recording material that is urged toward the conveyance drive roller and is pressed against the conveyance drive roller. A conveyance unit that conveys the recording material in the conveyance direction;
A liquid ejecting apparatus comprising: a liquid ejecting head that ejects and adheres liquid toward the recording material transported by the transport unit;
A drive disk that is coaxially mounted on the transport drive roller and rotates integrally with the transport drive roller;
A piezoelectric material plate that expands and contracts by applying a periodically changing voltage is included, and at least a part of the expansion and contraction motion contacts the circular surface of the drive disc and rotates the drive disc around the rotation axis. A liquid ejecting apparatus, further comprising an opposing member at a position where the bending stresses generated in the transport driving roller cancel each other when the actuator comes into contact with the driving disk. A rotary drive mechanism for driving a rotary body to rotate around a rotation axis,
In at least a part of the expansion and contraction movement, the drive disk includes a drive disk that is coaxially mounted on the rotation body and rotates integrally with the rotation body, and a piezoelectric material plate that expands and contracts by applying a periodically changing voltage. An actuator that contacts the circular surface of the drive disk and rotates the drive disk around the rotation axis, and the bending stress generated in the rotating body when the actuator contacts the drive disk A rotational drive mechanism in which opposing members are arranged so as to cancel each other.

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