JP2013233066A - Rotation drive transmission device and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation drive transmission device that can be installed in a small space, emits little noise, and has excellent rotation accuracy; and an image forming apparatus using the rotation drive transmission device.SOLUTION: A rotation drive transmission device includes: a plurality of piezoelectric members 1 that generate predetermined vibration; a drive member 2 that is connected with the piezoelectric members 1, and is driven by the vibration of the piezoelectric members 1; a rotation drive transmission member 3 that is rotated to be driven by the drive member 2 coming into contact therewith; a pressure member 4 that brings the drive member 2 into pressure contact with the rotation drive transmission member 3; and voltage application means that is controlled to apply a predetermined voltage to the respective plurality of piezoelectric members 1 in a constant cycle.

Description

  The present invention relates to a rotational drive transmission device and an image forming apparatus using the same.

  As a drive system used in an image forming apparatus such as a printer, a drive system that uses a transmission mechanism including a motor, a gear, a timing belt, and the like to transmit rotational drive power to a roller or the like is employed. In recent years, printers are increasingly required to have specifications for downsizing, low noise, and high image quality.

  However, as long as the above drive system is adopted, it is inevitably necessary to increase the machine size by providing a space between the motor and the gear, to generate motor noise, and to mesh with the rotation cycle of the motor and the gear. Various problems occur, such as generation of jitter at a high frequency.

  To deal with these problems, measures such as increasing the machine size are designed to be as compact as possible, applying grease to the gear tooth surface as a noise countermeasure, improving the gear accuracy against the occurrence of jitter, and applying grease. Conventionally applied.

  Patent Document 1 discloses that a traveling wave is generated in an elastic body that is vibrated by a piezoelectric element (electromechanical transducer) in order to achieve small size, high output, high efficiency, low vibration, and low noise. An ultrasonic driving device that rotates a rotating body is disclosed.

  However, the conventional measures described above cannot avoid the increase in machine size by the size of the motor and gear, and the number of parts increases accordingly, and grease is applied. Even if the noise is reduced, the effect is thin and the effect of applying the grease is great with respect to the reduction of jitter, but there is a problem that the grease cannot be applied to a portion that the user may touch.

  Further, in the ultrasonic driving device disclosed in Patent Document 1, a traveling wave is generated by ultrasonically vibrating a piezoelectric element, and driving force is supplied to a rotating body. The problem of point reduction is still not solved.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and uses a ultrasonic motor technology to save space, reduce noise, and provide a rotational drive transmission device with excellent rotational accuracy, and an image forming apparatus using the same. The purpose is to provide.

  In order to solve the above-described problem, the rotational drive transmission device according to the present invention described in claim 1 includes a plurality of piezoelectric members that generate predetermined vibrations, and a drive that is coupled to the piezoelectric members and is driven by vibrations of the piezoelectric members. A predetermined voltage is applied to each of the plurality of piezoelectric members, a member, a rotation drive member that rotates when the drive member abuts, a pressure member that presses the drive member against the rotation drive member, and the plurality of piezoelectric members Voltage application means controlled to do.

  According to the present invention, it is possible to provide a rotary drive transmission device that is compact and low in noise and has improved rotation accuracy of a rotating object, and an image forming apparatus using the rotation drive transmission device.

It is a side view explaining the general view of the rotational drive mechanism using the ultrasonic vibration of the rotational drive transmission apparatus in the embodiment of the present invention. It is sectional drawing explaining the principle of the rotational drive mechanism using the ultrasonic vibration of the rotational drive transmission apparatus in embodiment of this invention. It is a side view explaining the rotational drive transmission device which the drive object in embodiment of this invention is a rotary body, and was provided with the pressurization mechanism and the piezoelectric element in the to-be-rotated body side. It is a side view explaining the rotational drive transmission apparatus which the drive object in embodiment of this invention is a rotary body, has a pressurization mechanism in the rotary body side, and was equipped with the piezoelectric element in the to-be-rotated body side. It is a side view explaining the rotational drive transmission device which the drive object in embodiment of this invention is a belt shape, and was equipped with the piezoelectric element in the to-be-rotated body side. In the embodiment of the present invention, the rotating object is a rotating body, a rotating mechanism is provided with a pressurizing mechanism, and the rotating body is provided with a piezoelectric element on the entire surface in contact with the rotating body and parallel to the central axis of the cylinder. It is a figure explaining an apparatus. In the embodiment of the present invention, a rotating object is a rotating body, a rotating mechanism is provided with a pressurizing mechanism, and a rotating body is provided with a piezoelectric element at a part of contact with the rotating body parallel to the central axis of the cylinder. It is a figure explaining a drive transmission device. In the embodiment of the present invention, the object to be driven is a rotating body and a belt, a rotating mechanism is provided with a pressurizing mechanism, and the rotating body is provided with a piezoelectric element at a part of the contact point with the rotating body parallel to the central axis of the cylinder. It is a figure explaining the rotating drive transmission device which is.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified thru | or abbreviate | omitted suitably. According to the present invention, in order to generate a driving force (frictional force) using ultrasonic vibration, a pressing force is required in addition to the vibration by the piezoelectric element, and the pressing force is from a mechanism that makes the rotating body and the rotated body contact each other. It is characterized by obtaining directly.

  First, the rotational drive mechanism of the rotational drive transmission device in the embodiment of the present invention will be described. FIG. 1 is a side view for explaining an overview of a rotary drive mechanism using ultrasonic vibration of a rotary drive transmission device according to an embodiment of the present invention. In FIG. 1, the rotation drive mechanism 10 includes a piezoelectric element 1, a rotated body 2 (drive member), a rotation body (rotation drive member) 3, a pressure mechanism (pressure member) 4, and an elastic body 5. It is composed of

  The to-be-rotated body 2 provided with the piezoelectric element 1 is in contact with the rotating body 3 as a condition. Therefore, the contact surface between the rotated body 2 and the rotating body 3 has a curved shape. The arrow direction indicates the rotation direction of the rotating body 3. Further, as shown in FIG. 1, there are a plurality of piezoelectric elements 1, and each is controlled so that a predetermined voltage is applied at a constant period by a voltage application circuit (not shown).

  That is, when the elastic body 5 is pressed against the rotating body 3 while the piezoelectric element 1 is vibrated, the frictional force in the direction of the arrow advances between the elastic body 5 and the rotating body 3 according to the principle of an ultrasonic motor. A wave is generated. By utilizing this force, the rotating body 3 is rotated in the clockwise direction. The rotation speed depends on the period of the applied voltage.

  Next, the principle of the rotational drive mechanism of the rotational drive transmission device in the embodiment of the present invention will be described. FIG. 2 is a cross-sectional view illustrating the principle of a rotational drive mechanism using ultrasonic vibration of the rotational drive transmission device according to the embodiment of the present invention. In FIG. 2, the rotation drive mechanism 10 includes a piezoelectric element 1, a rotated body 2, a rotating body 3, and an elastic body 5.

  The piezoelectric element 1 vibrates when a predetermined voltage is applied by a voltage application circuit (not shown). When the piezoelectric element 1 vibrates, particles on the surface of the elastic body 5 start elliptical motion, so that a traveling wave is generated in the direction of the arrow pointing to the right of the rotating body 3 and the rotating body 3 rotates.

  That is, FIG. 2 explains the generation mechanism of the traveling wave of the frictional force explained in FIG. When the piezoelectric element 1 vibrates, the particles on the surface of the elastic body 5 perform an elliptical motion indicated by a counterclockwise arrow. Since the rotated body 2 is pressurized by the pressurizing mechanism 4 (FIG. 1), a vertical drag proportional to the applied pressure is generated between the elastic body 5 and the rotating body 3.

  Nothing is generated only by the vibration of the piezoelectric element 1, but when a vertical drag proportional to the applied pressure is generated there, a traveling wave of frictional force is generated in the right direction according to the principle of an ultrasonic motor. When the traveling wave torque becomes greater than or equal to the load torque of the rotator 3, the rotator 3 is driven to rotate in the direction of the arrow pointing to the right.

  FIG. 3 is a side view for explaining a rotational drive transmission device in which an object to be driven in the embodiment of the present invention is a rotating body, and a pressure mechanism and a piezoelectric element are provided on the rotating body side. In FIG. 3, the rotation drive mechanism 10 includes a piezoelectric element 1, a rotated body 2, a rotating body 3, a pressurizing mechanism 4, and an elastic body 5. The piezoelectric element 1 vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  A rotation drive mechanism 10 shown in FIG. 3 is an example of a rotation drive mechanism, and a pressurizing mechanism 4 is provided on the rotated body 2 side. Here, although the to-be-rotated body 2 demonstrates as what has a cylindrical shape in FIG. 3, as shown in FIG. 1, it may not be a cylindrical shape. The rotating body 3 rotates clockwise. Based on the principle of operation described in FIG. 2 above, the piezoelectric element 1 vibrates, whereby a traveling wave of frictional force is generated in the clockwise direction of the rotating body 3 and the rotating body 3 is driven to rotate.

  Next, in the rotation drive mechanism of the rotation drive transmission device according to the embodiment of the present invention, a case where pressure is applied to the pressure mechanism on the rotating body side will be described. FIG. 4 is a side view for explaining a rotary drive transmission device in which an object to be driven in the embodiment of the present invention is a rotating body, a pressure mechanism is provided on the rotating body side, and a piezoelectric element is provided on the rotated body side. In FIG. 4, the rotation drive mechanism 10 includes a piezoelectric element 1, a rotated body 2, a rotating body 3, a pressurizing mechanism 4, and an elastic body 5. Note that there are a plurality of piezoelectric elements 1, and each vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  The rotational drive mechanism 10 shown in FIG. 4 is the reverse type of the rotational drive mechanism 10 shown in FIG. 3 and is provided with a pressurizing mechanism 4 on the rotating body 3 side. In addition, although the to-be-rotated body 2 demonstrates as what has a cylindrical shape in FIG. 4, as shown in FIG. 1, it may not be a cylindrical shape. The rotating body 3 rotates in the direction of the arrow. This also drives the rotating body 3 using the operating principle described in FIG. 2 above, but the traveling wave of the frictional force is generated between the rotating body 3 provided with the pressurizing mechanism 4 and the elastic body 5. To generate rotational driving force.

  FIG. 5 is a side view for explaining a rotational drive transmission device in which an object to be driven in the embodiment of the present invention has a belt shape and includes a piezoelectric element on the rotating body side. In FIG. 5, the rotation drive mechanism 10 includes a piezoelectric element 1, a rotated body 2, a rotation body 3, a pressurization mechanism 4, an elastic body 5, and a drive transmission belt (transmission member) 6. Yes. The piezoelectric element 1 vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  The rotational drive mechanism 10 of FIG. 5 is an example in the case where the target for transmitting rotational drive (rotational drive torque) includes the drive transmission belt 6. After the power is directly transmitted to the drive transmission belt 6, the rotating body 3 is driven. In FIG. 5, the drive transmission belt 6 is composed of two axes, but may be composed of multiple axes. Each rotator 3 rotates in the direction of the arrow.

  Belt tension is generated in the drive transmission belt 6 (for example, a transfer belt in the image forming apparatus) by the pressurizing mechanism 4 (for example, the image forming apparatus has a function as a tension spring of the transfer unit). Then, a vertical drag is generated between the drive transmission belt 6 and the elastic body 5. In this state, when the piezoelectric element 1 is vibrated, a traveling wave is generated between the drive transmission belt 6 and the elastic body 5 according to the operation principle described in FIG. To drive.

  FIG. 6 shows a driving object according to an embodiment of the present invention, in which a rotating body is provided, a pressure mechanism is provided on the rotating body side, and a piezoelectric element is provided on the entire surface of the contact portion with the rotating body in parallel with the central axis of the cylinder. It is a figure explaining the rotational drive transmission device which is. In FIG. 6, the rotation drive mechanism 10 includes a piezoelectric element 1, a cylindrical rotated body 2, a cylindrical rotating body 3, a pressurizing mechanism 4, and an elastic body 5. The piezoelectric element 1 vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  The rotary drive mechanism 10 in FIG. 6 is a view of the entire configuration of the rotary drive mechanism 10 shown in FIG. The piezoelectric element 1 is parallel to the central axis of the cylinder, and on the rotated body 2 side, the elastic body 5 and the rotated body 2 are disposed over the entire contact surface where the rotated body 2 contacts the rotating body 3. It is installed between. The rotating body 3 rotates in the direction of the arrow.

  The rotation driving mechanism 10 can be applied to registration roller driving in the image forming apparatus. The registration roller is always provided with a pressure roller facing the resist roller, and the resist pressure acts as a vertical drag. Therefore, the registration roller has the elastic body 5 and the piezoelectric element 1 as shown in FIG. For example, the rotating body 3 (pressure roller) can be rotated by the operating principle described in FIG.

  In principle, a similar function can be obtained even when a paper medium is inserted between the elastic body 5 and the rotating body 3 (pressure roller). If this method is adopted, a registration drive gear and a registration motor are not required, so that considerable space saving and low noise driving can be realized as compared with the conventional method.

  FIG. 7 shows a driving object in the embodiment of the present invention, which is a rotating body, which has a pressurizing mechanism on the rotating body side, and a piezoelectric element on a part to be contacted with the rotating body parallel to the central axis of the cylinder on the rotating body side. It is a figure explaining the rotational drive transmission device provided. In FIG. 7, the rotation drive mechanism 10 includes a piezoelectric element 1, a cylindrical rotated body 2, a cylindrical rotating body 3, a pressurizing mechanism 4, and an elastic body 5. The piezoelectric element 1 vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  FIG. 7 is different from FIG. 6 in the installation location of the piezoelectric element 1. The piezoelectric element 1 is installed in a part of a contact surface that is parallel to the central axis of the cylinder and that contacts the rotating body 3 on the rotating body 2 side in order to eliminate left-right deviation and reduce costs. Yes. The rotating body 3 rotates in the direction of the arrow.

  Although this embodiment is performed in order to satisfy both the purpose of eliminating the lateral deviation of the traveling wave of the generated frictional force and the purpose of cost reduction, as described in FIG. When the drive mechanism 10 is applied to the image forming apparatus, a speed difference may occur when the magnitude of the vertical drag differs depending on whether or not the paper medium is inserted. In order to prevent the influence of the paper medium, The piezoelectric element 1 is installed outside the pass region.

  FIG. 8 shows a driving object in the embodiment of the present invention, which is a rotating body and a belt, and a rotating mechanism is provided with a pressurizing mechanism, and the rotating body is parallel to the central axis of the cylinder and part of a contact point with the rotating body. It is a figure explaining the rotational drive transmission device provided with the piezoelectric element. In FIG. 8, the rotational drive mechanism 10 includes a piezoelectric element 1, a cylindrical rotated body 2, two cylindrical rotational bodies 3, a pressurizing mechanism 4, an elastic body 5, and a drive transmission belt 6. It is composed of The piezoelectric element 1 vibrates at a constant period when a predetermined voltage is applied by a voltage application circuit (not shown).

  That is, as shown in FIG. 8, the drive transmission belt 6 is included as a drive target. This embodiment is different from the rotational drive mechanism shown in FIG. 5. First, power is transmitted to the shaft, and then the drive transmission belt 6 is driven. The piezoelectric element 1 is installed in a part of a contact surface that is parallel to the central axis of the cylinder and that contacts the rotating body 3 on the rotating body 2 side in order to eliminate left-right deviation and reduce costs. Yes.

  This example can be applied to drive a transfer belt of a transfer unit in an image forming apparatus. That is, a secondary transfer roller is always provided in the secondary transfer portion so as to face the secondary transfer portion, and the secondary rolling pressure acts as a vertical drag. If the secondary transfer pressure is applied to the secondary transfer roller in the form of the piezoelectric element 1 and the elastic body 5, a rotational driving force is generated in the rotating body 3 (medium transfer driving roller) so that the transfer belt is driven. Become. If this drive system is adopted, a transfer drive gear and a transfer motor are not required, so that considerable space saving and noise reduction can be realized as compared with the conventional drive system.

  As described above, the rotational drive transmission device according to the embodiment of the present invention is rotationally driven using the frictional force generated between the piezoelectric element and the elastic body that are vibrated with an ultrasonic cycle using an ultrasonic motor. A rotational drive mechanism that obtains force is employed, and this rotational drive transmission device can be mounted on the image forming apparatus.

  As described above, according to the present invention, the same effect as that of an ultrasonic motor is aimed, and a traveling wave obtained by vibrating the attached piezoelectric element, and a rotating body and a rotated body are in pressure contact. And a rotational drive transmission device capable of increasing the rotational accuracy of the rotating object in a compact and low-noise manner by rotating the rotating body that is the driving object by using the frictional force generated by An image forming apparatus using this can be provided.

  The present invention has been described above by the preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments thereof, various modifications and changes can be made to these embodiments without departing from the broader spirit and scope of the invention as defined in the claims. is there.

DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Rotating body (drive member)
3 Rotating body (Rotary drive member)
4 Pressurizing mechanism 5 Elastic body 6 Drive transmission belt (transmission member)
10 Rotation drive mechanism

JP 05-191987

Claims (8)

A plurality of piezoelectric members that generate predetermined vibrations;
A driving member coupled with the piezoelectric member and driven by vibration of the piezoelectric member;
A rotation drive member that rotates when the drive member abuts;
A pressure member that presses the drive member against the rotary drive member;
Voltage applying means controlled to apply a predetermined voltage to each of the plurality of piezoelectric members at a constant period;
A rotational drive transmission device comprising: A plurality of the rotation drive members are provided, and the plurality of rotation drive members are connected by a transmission member that transmits the rotation drive to each other along the rotation circumferential direction thereof.
The drive member is press-contacted by the pressure member so as to be pressed against any of the plurality of rotation drive members provided, and then a predetermined voltage is applied to the piezoelectric member at a constant period. The rotational drive transmission device according to claim 1. The rotary drive member and the drive member both have a cylindrical shape having a predetermined radius,
The rotational drive according to claim 2, wherein the piezoelectric member is provided in a part of a region that is parallel to the central axis of the cylindrical shape and abuts on the rotational drive member of the drive member. Transmission device. A plurality of piezoelectric members that generate predetermined vibrations;
A driving member coupled with the piezoelectric member and driven by vibration of the piezoelectric member;
A rotation drive member that rotates when the drive member abuts;
A pressure member that presses the rotational drive member against the drive member;
And a voltage applying means controlled to apply a predetermined voltage to each of the plurality of piezoelectric members at a constant period. A plurality of the rotation drive members are provided, and the plurality of rotation drive members are connected by a transmission member that transmits the rotation drive along the rotation circumferential direction to each other,
The pressure member presses the rotation drive member in the outer peripheral direction of the transmission member,
The rotation drive transmission device according to claim 4, wherein a predetermined voltage is applied to each of the plurality of piezoelectric members at a constant period. The drive member and the rotary drive member both have a cylindrical shape having a predetermined radius,
The rotational drive transmission according to claim 5, wherein the piezoelectric member is provided on the entire surface of the drive member that is parallel to the central axis of the cylindrical shape and is in contact with the rotational drive member. apparatus. The drive member and the rotary drive member both have a cylindrical shape having a predetermined radius,
The rotational drive according to claim 5, wherein the piezoelectric member is provided in a part of a region that is parallel to the central axis of the cylindrical shape and contacts the rotational drive member of the drive member. Transmission device.   An image forming apparatus comprising the rotational drive transmission device according to claim 1.

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