JP2012152997A - Driving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of preventing tooth skipping even when a driving force acts on a first pulley in such a state that a driving body reaches the end of the moving area.SOLUTION: The driving mechanism for driving a driving body mounted on a belt by a belt hung over a first pulley and a second pulley includes a conversion means for converting a force containing a component acting on the driving body in a direction from the first pulley side to the second pulley side into a force for maintaining or increasing the distance between the first pulley and the second pulley.

Description

  The present invention relates to a drive mechanism that reciprocates a drive body with a belt.

  2. Description of the Related Art Conventionally, in a drive mechanism that drives a drive body by the operation of a belt, for example, a drive mechanism such as a carriage of an ink jet printer, the drive body is attached to a belt that is hung on a first pulley and a second pulley, The carriage that follows the belt is reciprocated by being driven to rotate. In the prior art, generally, a tooth surface is formed on the first pulley, the second pulley, and the belt, and the belt is configured to accurately follow the rotation of the first pulley by meshing the teeth. However, tooth skipping occurs depending on the operation of the first pulley. Therefore, a technique is known in which the second pulley is supported by the second pulley support and the tooth jump is suppressed by providing a biasing means for biasing the second pulley support in the direction in which the belt is tensioned. (For example, Patent Document 1).

JP 2008-30453 A

  Even if the conventional technology described above is used, it is difficult to suppress tooth skipping due to excessive driving force. For example, in an inkjet printer, a prescribed initial operation involving positioning of the carriage and the like is performed after power is turned on, and an operation of moving the carriage from end to end of the moving range may be performed in the positioning. However, if the power is turned on when the carriage position is not specified due to an error such as the print medium being jammed in the transport path, it is unclear how much the carriage will reach the end of the moving range. The drive of the first pulley cannot be stopped even though the carriage has reached the end of the moving range.

Even in the configuration including the above-described conventional technology, in such a case, the first pulley is driven even though the carriage cannot move, and the driving force transmitted to the belt acts as a force for moving the carriage. It will be in a state that does not. Therefore, the driving force transmitted to the belt acts as a force for bringing the second pulley support close to the first pulley against the urging force by the urging means. As a result, the second pulley approaches the first pulley together with the second pulley support, and the belt is not stretched, causing tooth skipping. As described above, the configuration in which the driving body is driven by the belt is adopted not only in the carriage driving mechanism in the printer but also in various devices.
The present invention has been made in view of the above problems, and even when a driving force is applied to the first pulley in a state where the driving body reaches the end of the moving range, the tooth of the first pulley, such as tooth jumping, can be obtained. It is an object of the present invention to provide a technique capable of preventing a situation in which the movement of the belt does not follow the rotation.

  In order to achieve the above object, in a driving mechanism for driving a driving body attached to the belt by a belt hung on the first pulley and the second pulley, the first pulley side acting on the driving body is changed from the first pulley side to the second pulley side. The converting means for converting the force including the component in the direction toward the head into a force that maintains or increases the distance between the first pulley and the second pulley. That is, the driving body moves in the movement path from the end on the second pulley side to the end on the first pulley side as the belt is driven, and the driving body moves in the movement path from the first pulley side to the second side. In the process of moving to the pulley side, at least a part of the force for moving the driving body is converted by the converting means into a force for maintaining or increasing the distance between the first pulley and the second pulley. For this reason, when the conversion of the force is performed, the belts hung on the first pulley and the second pulley are stretched. Therefore, even when the driving force is applied to the first pulley with the driving body reaching the end of the moving range, a state in which the movement of the belt does not follow the rotation of the first pulley occurs, such as tooth skipping. Can be prevented.

  Here, the converting means converts a force including a component in a direction from the first pulley side to the second pulley side acting on the driving body into a force for maintaining or increasing the distance between the first pulley and the second pulley. I can do it. Therefore, it is sufficient that the force acting on the driving body by contacting with the driving body is directly or indirectly applied to at least one of the first pulley and the second pulley. The configuration for indirectly applying the force may be a configuration using various elastic bodies such as springs and rubbers, and a part of the force of the driving body is connected to the first pulley via a hydraulic mechanism. It may be configured to act on at least one of the second pulley.

  Further, in the configuration in which the first pulley is rotatably supported by the support and is driven to rotate by the motor, the second pulley can be moved and the distance from the first pulley can be changed. A force may be applied to the pulley to maintain or increase the distance between the first pulley and the second pulley. For example, the second pulley is supported by the second pulley support, and further, the second pulley support is supported by the support so as to be movable in a direction in which the distance between the second pulley and the first pulley is changed. The second pulley is supported by the support via the second pulley support portion. The support may be integral with the support that rotatably supports the first pulley, or may be a separate body.

  Further, the tension generating means applies a force to the second pulley support portion so that a force is applied to the belt from the second pulley to the belt in a state where the belt is applied to the first pulley and the second pulley. Make it work. That is, in a state where the belt is applied to the first pulley and the second pulley, the tension generating means applies a force to the second pulley support portion, and the force acting on the second pulley support portion is transmitted to the second pulley. As a result, a force is applied to the belt from the second pulley so as to tension the belt. In this configuration, the second pulley support portion is provided with a contact portion that comes into contact with the driving body that moves from the first pulley side to the second pulley side. That is, when the driving body comes into contact with the contact portion, the force including the component in the direction from the first pulley side to the second pulley side acting on the driving body maintains or increases the distance between the first pulley and the second pulley. It is converted into the force to make.

  Therefore, when the drive body reaches the contact portion provided in the second pulley support portion in the process of moving the drive body from the first pulley side to the second pulley side in the movement path, the contact portion acts on the drive body. The force to be transmitted is transmitted to the second pulley support portion, and the force acts on the second pulley from the second pulley support portion, whereby the distance between the first pulley and the second pulley is maintained or increased. As a result, the second pulley together with the second pulley support portion can be prevented from approaching the first pulley, the belt can be prevented from being tensioned, and the belt can be moved during the rotation of the first pulley. It is possible to prevent the occurrence of a state that does not follow.

  Here, the second pulley support portion is supported by the support body so as to be movable in a direction in which the distance between the second pulley and the first pulley is changed. That is, the distance between the second pulley and the first pulley may be changed by moving the second pulley support portion with respect to the support body together with the second pulley. Here, the distance between the second pulley and the first pulley may be changed, and the moving direction of the second pulley support portion may be parallel to the straight line connecting the second pulley and the first pulley, or non-parallel. It may be. In any case, it is sufficient that the tension acting on the belt applied to the second pulley and the first pulley is adjusted by changing the distance between the second pulley and the first pulley.

  The tension generating means only needs to be able to apply a force that causes the belt to be stretched from the second pulley to the belt in a state where the belt is hung on the first pulley and the second pulley. For example, the first end is attached to the support, and the other end is attached to the second pulley support, and the first tension is applied to the belt from the second pulley to the belt. It is possible to adopt a configuration in which force is applied to the two pulley support portion. In other words, since the repulsive force of the spring increases as the displacement of the spring increases, even if a force opposite to the force that causes the belt to tension is applied to the belt, if the configuration uses the spring, It becomes easy to maintain the belt tensioned against the force, which is preferable. Then, the force including the component in the direction from the first pulley side to the second pulley side acting on the driving body by the contact portion is converted into a force for maintaining or increasing the distance between the first pulley and the second pulley. Thus, it is possible to easily assist the spring force, and it is possible to easily prevent a situation in which the movement of the belt does not follow the rotation of the first pulley.

  Furthermore, the contact part with which a 2nd pulley support part is provided should just be a member which contacts the drive body which moves to the 2nd pulley side from the 1st pulley side. That is, since the belt is hung on the first pulley and the second pulley, one end of the moving range of the driving body is on the second pulley side and the other end is on the first pulley side. Therefore, if a member projecting from the second pulley support portion to the movement path of the drive body is formed on the second pulley support portion located on one end side of the drive body movement range, the drive body movement range is changed. The driving body and the contact portion can be brought into contact with each other at the end of the two pulleys. Moreover, the contact part should just be a member which can transmit the force which acts on a drive body by contacting a drive body to a 2nd pulley support part, and is comprised integrally with a 2nd pulley support part. Alternatively, it may be configured to be attached to the second pulley support portion.

  In any case, according to this configuration, it is possible to configure the contact portion that contacts the driving body only by configuring the contact portion with the member protruding from the second pulley support portion that supports the second pulley, and the simple configuration. The contact portion can be configured by the configuration. Of course, the configuration of the contact portion is not limited to the protruding portion provided in the second pulley support portion, and various other configurations can be employed. For example, in a process in which the driving body moves from the first pulley side to the second pulley side, the protruding portion protruding from the driving body may be in contact with the second pulley support portion. In this structure, the surface on the 2nd pulley support part which the protrusion part protruded from the drive body contacts will comprise a contact part.

  Further, as in the present invention, the force including the component in the direction from the first pulley side to the second pulley side acting on the driving body is changed to the force for maintaining or increasing the distance between the first pulley and the second pulley. The conversion method can also be applied as a method. In addition, the apparatus and method as described above may be realized as a single apparatus or may be realized using a shared component in an apparatus having multiple functions, including various aspects. It is a waste.

(1A) is a diagram showing a printer provided with a drive mechanism according to an embodiment of the present invention, (1B) is a front view of the drive mechanism, (1C) is a front view showing a state in which a support is excluded from (1B), (1D) is a diagram illustrating a state in which the second pulley, the second pulley support, and the spring are disassembled. (2A) is a top view showing a state in which the support is removed from (1B), (2B) is a view showing a state in which the second pulley, the second pulley support part, and the spring are disassembled, and (2C) is a view of the support Front view, (2D) is a top view of the support. (3A) is a view showing a scanner including a drive mechanism according to an embodiment of the present invention, and (3B) is a top view of the drive mechanism.

Here, embodiments of the present invention will be described in the following order.
(1) Printer configuration:
(2) Carriage drive mechanism:
(3) Other embodiments:

(1) Printer configuration:
FIG. 1A is a diagram illustrating a schematic configuration of a printer 10 including a drive mechanism according to an embodiment of the present invention. In FIG. 1A, a perspective view of the casing of the printer 10 is shown in a three-dimensional space including an x-axis, a y-axis, and a z-axis. In other words, the printer 10 includes a substantially rectangular parallelepiped housing, and when the printer 10 is placed on a horizontal plane, the surface including the insertion port 11 for the print medium P is oriented parallel to the horizontal plane and includes the discharge port 12 for the print medium P. The plane is oriented perpendicular to the horizontal plane. Therefore, in the present specification, the x axis, the y axis, and the z axis so that the surface including the insertion port 11 is parallel to the xy plane and the xz plane is perpendicular to the surface including the insertion port 11. Axis set. Furthermore, the edge of the casing of the printer 10 was set so as to be oriented in parallel with each of the x axis, the y axis, and the z axis.

  The printer 10 according to the present embodiment can transport the print medium P inserted from the insertion port 11 of the print medium P and discharge it from the discharge port 12. The printer 10 includes a carriage 13 as a driving body and a mechanism for moving the carriage. The mechanism for moving the carriage includes a support body 20 fixed to the housing of the printer 10 in the printer 10, a first pulley 30 and a second pulley 40 supported by the support body 20, a first pulley 30, and And a belt 50 hung on the second pulley 40.

  The support 20 is a plate-like member oriented in a direction parallel to the xz plane, and the first pulley 30 and the second pulley 40 are supported rotatably with respect to the support 20. In the present embodiment, the first pulley 30 is directly supported by the support body 20, but the second pulley 40 is indirectly supported by the support body 20 via the second pulley support portion 41. The second pulley support portion 41 will be described later.

  A carriage 13 is attached to the belt 50 that is hung between the first pulley 30 and the second pulley 40, and the belt is reciprocated in a direction parallel to the x-axis direction by rotationally driving the first pulley 30. The carriage 13 can be reciprocated in a direction parallel to the x-axis direction. The first pulley 30 and the second pulley 40 are disposed at both ends of the support 20 in the direction parallel to the x-axis. That is, the first pulley 30 is supported on one end portion in the direction along the x-axis on the support body 20, and the second pulley 40 is supported on the other end in the direction along the x-axis on the support body 20. The print medium P is transported in a direction parallel to the y-axis between the first pulley 30 and the second pulley 40. Accordingly, in the process of transporting the print medium P, the carriage 13 is reciprocated in a direction parallel to the x-axis, and an image is printed on the print medium P by ejecting ink from the ink head mounted on the carriage 13. can do.

(2) Carriage drive mechanism:
In this embodiment, in the printer 10 as described above, the tension of the belt 50 is maintained by the spring, and the first pulley 30 and the belt 50 can be transmitted even when the force against the repulsive force of the spring can be transmitted to the belt 50. The carriage drive mechanism is configured so that tooth skipping between the second pulley 40 and the belt 50 does not occur. The carriage drive mechanism will be described in detail below.

  FIG. 1B is a front view showing a state where the carriage drive mechanism is extracted and viewed from a direction parallel to the y-axis, and FIG. 1C shows a state viewed from a direction parallel to the y-axis excluding the support 20 from FIG. FIG. 1D is a front view of the second pulley 40, the second pulley support 41 that supports the second pulley 40, and the spring 42 that is attached to the second pulley support 41, and is viewed from a direction parallel to the y-axis. It is a figure which shows a state. 2A is a top view showing a state viewed from a direction parallel to the z-axis excluding the support 20 from FIG. 1B, and FIG. 2B is an exploded view of the second pulley 40, the second pulley support 41, and the spring 42. It is a figure which shows the state seen from the direction parallel to az axis. 2C is a front view showing a state in which the support 20 is viewed from a direction parallel to the y-axis, and FIG. 2D is a top view showing a state in which the support 20 is viewed from a direction parallel to the z-axis.

  As shown in FIG. 2A, the first pulley 30 includes a flange 30a, a cylindrical portion 30b, and a rotating body 30c. The rotating body 30c rotates with respect to a rotation shaft (not shown) extending from the flange 30a to the opposite side of the cylindrical portion 30b. Installed as possible. On the other hand, a hole 20a is formed at one end of the support 20 along the x-axis (see FIG. 2C), and the cylindrical portion 30b of the first pulley 30 is inserted into the hole 20a of the support 20. Thus, the first pulley 30 is supported with respect to the support 20. The rotating body 30c is rotatable with the first pulley 30 supported by the support body 20, and the first pulley 30 is supported rotatably with respect to the support body 20.

  In addition, the unevenness | corrugation extended in the direction parallel to the rotating shaft of the rotary body 30c is formed in the outer peripheral part of the rotary body 30c. That is, a tooth surface is formed on the outer periphery of the rotating body 30c. The printer 10 includes a motor 60, and the motor 60 is connected to the first pulley 30. Therefore, the first pulley 30 can be rotated clockwise or counterclockwise in FIG. 1B by rotating the motor 60 in a predetermined direction or in the reverse direction.

  2B etc., the 2nd pulley 40 is provided with the rotary body 40a and the rotating shaft 40b, and the unevenness | corrugation extended in the direction parallel to the rotating shaft 40b of the rotating body 40a in the outer peripheral part of the rotating body 40a The tooth surface is formed by.

  2B etc., the 2nd pulley support part 41 is equipped with plate-shaped member 41a-41c and connection part 41d, 41e, and the plate-shaped member 41a-41 in the state which the said plate-shaped member 41a-41c orientated in parallel. The plate-like members 41a to 41c are connected by connecting portions 41d and 41e extending vertically from 41c. Further, the second pulley support portion 41 includes a contact portion 41f and a spring receiving portion 41g, and the contact portion 41f is a plate-like member and is connected to the plate-like member 41b and the connection in a state of being oriented perpendicularly to the plate-like member 41b. A cylindrical spring receiving portion 41g that is attached to the portion 41e and extends vertically from the contact portion 41f is attached to the contact portion 41f.

  In the present embodiment, the largest surface of the contact portion 41f is oriented parallel to the zy plane, and the spring receiving portion 41g is attached to the contact portion 41f so as to be oriented parallel to the x-axis. In addition, the outer diameter of the spring receiving portion 41g is configured to be slightly smaller than the inner diameter of the spring 42, and the spring 42 can be inserted into the spring receiving portion 41g.

  On the other hand, in the support 20, a hole 20 b is formed at the end opposite to the first pulley 30. The hole 20b has a shape in which rectangular holes of different sizes are arranged and connected in the x-axis direction, and a portion corresponding to the large rectangular hole (on the right side in the hole 20b of the support 20 shown in FIG. 2C). The hole 20b is formed so that the position is larger than the outer periphery of the plate-like members 41a and 41b (the outer periphery when viewed from the xz plane (for example, the outer periphery in FIG. 1D)). Further, a hole 20b is formed so that a portion corresponding to a small rectangular hole (a portion located on the left side in the hole 20b of the support 20 shown in FIG. 2C) is smaller than the outer periphery of the plate-like members 41a and 41b. Yes. Further, the distance between the plate-like member 41a and the plate-like member 41b is slightly larger than the thickness of the support 20 in the direction parallel to the y-axis.

  Accordingly, a part of the second pulley support portion 41 is inserted into a rectangular portion having a large hole 20b, and the second pulley support portion 41 is small in the hole 20b with the support member 20 sandwiched between the plate-like members 41a and 41b. The second pulley support portion 41 is supported by the support 20 by sliding to the rectangular portion. In this state, the second pulley support portion 41 can be reciprocated in a direction parallel to the x axis.

  Furthermore, in the support body 20, the plate-shaped member 20c is connected along the side nearest to the hole 20a of the hole 20b (refer FIG. 2C and 2D). The plate-like member 20c is perpendicular to the xz plane and parallel to the yz plane, and is connected to a columnar spring receiving portion 20d. The spring receiving portion 20d is oriented so that its axis is parallel to the x-axis and protrudes toward the hole 20b, and the outer diameter of the spring receiving portion 20d is slightly smaller than the inner diameter of the spring 42. The spring 42 can be inserted into the spring receiving portion 20d.

  Therefore, in the state where the second pulley support portion 41 is supported by the support 20 so as to be able to reciprocate in the direction parallel to the x-axis as described above, the spring receiving portion 41g is inserted into one end portion of the spring 42, A state in which the spring 42 is held between the second pulley support portion 41 and the plate-like member 20c as shown in FIG. 1B by setting the spring receiving portion 20d to the other end of the spring 42. It can be. In the present embodiment, the spring 42 is configured to be held between the second pulley support portion 41 and the plate-like member 20c in a contracted state. Therefore, the repulsive force of the spring 42 acts as a force that urges the second pulley support portion 41 that can reciprocate in the hole 20b to the left side of FIG. 1B.

  Furthermore, semicircular bearing portions 41h are formed on the plate-like members 41b and 41c included in the second pulley support portion 41 (see FIG. 1D). The bearing portion 41h has an inner diameter that is slightly larger than the outer diameter of the rotating shaft 40b included in the second pulley 40. Therefore, the rotating shaft 40 b of the second pulley 40 can be fitted to the bearing portion 41 h of the second pulley support portion 41. In the state where the spring 42 is held between the second pulley support portion 41 and the plate-like member 20c as described above, the second pulley support portion 41 is moved to the first pulley 30 side by the repulsive force of the spring 42. It is suppressed that it moves to.

  In view of this, the tooth provided in the second pulley 40 and the first pulley 30 is a belt 50 having a tooth surface in a state in which the rotating shaft 40b of the second pulley 40 is fitted to the bearing portion 41h of the second pulley support portion 41. When the belt 50 is engaged with the surface, the belt 50 is stretched so that the belt 50 does not fall off from the second pulley 40 and the first pulley 30. In this case, since the 2nd pulley 40 is hold | maintained in the state which does not drop from the 2nd pulley support part 41, the 2nd pulley 40 will be supported by the 2nd pulley support part 41 rotatably.

  In the present embodiment, the carriage 13 includes a plate-like member 13a (see FIG. 2A), and the plate-like member 13a is attached to the belt 50 existing on the lower side. Further, in the present embodiment, the spring 42 is set to a spring constant that gives the belt 50 tension capable of moving the carriage 13. Accordingly, when the first pulley 30 is rotated clockwise or counterclockwise in FIG. 1B by rotating the motor 60 in a predetermined direction or the reverse direction, the carriage 13 can be reciprocated in a direction parallel to the x axis. It is.

  As described above, the second pulley 40 is supported by the support body 20 via the second pulley support portion 41, and the second pulley support portion 41 is urged to the left side in FIG. Further, the first pulley 30 is supported on the opposite end portion (the right side in FIG. 1B) of the second pulley 40 in the support 20. Further, the second pulley support portion 41 can reciprocate along the direction parallel to the x axis in the hole 20b of the support 20 (movable to the left and right in FIG. 1B). Accordingly, the second pulley support portion 41 is movable in the proximity direction in which the second pulley 40 and the first pulley 30 are brought close to each other and in the separation direction in which the second pulley support portion 41 is separated from the first pulley 30, and at least between the first pulley 30 and the second pulley 40. In the state where 50 is applied, the belt 50 is supported by the support body 20 in a state in which a force that causes the belt 50 to be stretched acts on the belt 50.

  The printer 10 according to the present embodiment controls the rotational driving force of the motor 60 to move the carriage 13, but usually moves the carriage 13 within a predetermined movement range while specifying the position of the carriage 13. To perform printing. However, if an error occurs such as the print medium P being jammed in the transport path, the power of the printer 10 is stopped, the power is turned off, and the power is turned on again. There is a case. In this case, while the position of the carriage 13 is unknown, the carriage 13 is once moved to the end of the movement range to specify the position of the carriage 13, and after the position is specified, the normal operation is performed.

  As the carriage 13 is moved without knowing the position, the driving force is applied from the motor 60 to the first pulley 30 even though the carriage 13 is actually positioned at the end of the moving range and cannot move any further. A situation may occur that causes In this case, the driving force transmitted to the belt 50 does not act as a force for moving the carriage 13, and the driving force transmitted to the belt 50 causes the second pulley support 41 to resist the repulsive force of the spring 42. Acts as a force to move in the proximity direction. Then, when the second pulley support portion 41 moves in the proximity direction by the force in the proximity direction, the second pulley 40 and the second pulley support portion 41 approach the first pulley 30 and the belt 50 is not stretched. Tooth skipping occurs.

  If the spring 42 is used to bias the second pulley support portion 41 in the separating direction as in the present embodiment, the repulsive force of the spring 42 increases in proportion to the displacement of the spring 42, and thus the carriage 13. When the force in the proximity direction acts on the second pulley support portion 41 without being able to move, it is preferable because it becomes easy to maintain the belt tension against the force in the proximity direction. However, in order to prevent tooth jump when the carriage 13 cannot move using only the repulsive force of the spring 42, the spring constant of the spring 42 needs to be extremely large. It is impossible to prevent.

  Therefore, in the present embodiment, tooth skipping is prevented by contacting the carriage 13 that moves from the first pulley 30 side to the second pulley 40 and the contact portion 41f. That is, by providing the contact portion 41f protruding in the movement path of the carriage 13 in the second pulley support portion 41, the end portion of the carriage 13 in the process of moving the carriage 13 from the first pulley 30 side to the second pulley 40 side. Is configured to restrict movement so that the carriage 13 cannot move any further when it reaches the contact portion 41f. In the example shown in FIG. 2A, the carriage 13 comes into contact with the contact portion 41 at the position indicated by the one-dot chain line on the second pulley 40 side, and does not move to the position indicated by the broken line on the second pulley 40 side.

  As described above, when the carriage 13 comes into contact with the contact portion 41f, the force acting on the carriage 13 is transmitted to the second pulley support portion 41, and the force in the separation direction acts on the second pulley support portion 41. In addition, while the driving force for moving the carriage 13 in the same direction continues to act on the belt 50 from the motor 60, the force in the separation direction continues to act on the second pulley support portion 41 by the carriage 13.

  On the other hand, if the driving force for moving the carriage 13 continues to act on the belt 50 from the motor 60 while the carriage 13 is in contact with the contact portion 41f, the driving force transmitted to the belt 50 is repelled by the spring 42. This acts as a force that moves the second pulley support 41 in the proximity direction against the force. However, in the present embodiment, when the carriage 13 comes into contact with the contact portion 41f, a force in the separation direction continues to act on the second pulley support portion 41. Therefore, the second pulley 40 together with the second pulley support portion 41 can be prevented from approaching the first pulley 30, the belt 50 can be prevented from being stretched, and tooth skipping can be prevented. Is possible.

(3) Other embodiments:
The above-described embodiment is an example for carrying out the present invention, and a force including a component in a direction from the first pulley side acting on the driving body toward the second pulley side is applied between the first pulley and the second pulley. Various other embodiments can be employed as long as the distance is converted into a force that maintains or increases the distance. For example, the driving body is not limited to a carriage, and an apparatus including a driving mechanism is not limited to a printer.

  FIG. 3A is a diagram illustrating a schematic configuration of a scanner 100 including a drive mechanism according to an embodiment of the present invention. In FIG. 3A, a perspective view of the housing of the scanner 100 is shown in a three-dimensional space including an x-axis, a y-axis, and a z-axis. The scanner 100 includes a substantially rectangular parallelepiped housing and an openable / closable lid 110 attached to the housing by a hinge. One surface of the scanner 100 has a document table 120. When the scanner 100 is placed on a horizontal plane, the document table 120 is oriented parallel to the horizontal plane. Therefore, in this specification, the x-axis and y-axis are set so that the document table 120 placed on the horizontal plane is parallel to the xy plane, and the xz plane and the yz plane are perpendicular to the document table 120. The z axis was set. Further, the ridge of the housing of the scanner 100 was set so as to be oriented in parallel with each of the x axis, the y axis, and the z axis.

  The scanner 100 according to the present embodiment includes a line sensor 130 extending in one direction. The line sensor 130 is oriented below the document table 120 in parallel to the x-axis direction and parallel to the y-axis direction. It is configured to be movable.

  FIG. 3B is a top view showing a state in which the drive mechanism of the line sensor 130 is extracted and viewed from a direction parallel to the z-axis. In FIG. 3B, the same reference numerals are used for the same configurations as those in the above-described embodiment. As shown in FIG. 3B, the drive mechanism of the line sensor 130 according to the present embodiment is supported by the support members 200 and 201 fixed to the housing of the scanner 100 in the scanner 100, and can be rotated by the support member 200. The first pulley 30 supported, the second pulley support portion 41 supported by the support body 201, the second pulley 40 rotatably supported by the second pulley support portion 41, the first pulley 30 and the second pulley And a belt 50 hung on the pulley 40.

  The support 200 is a plate-like member oriented in a direction parallel to the xy plane, and the first pulley 30 is rotatably supported by the support 200 and is driven to rotate by a motor (not shown). The support 201 is a plate-like member oriented in a direction parallel to the xy plane, and has the same shape as the hole 20b of the support 20 described above. Therefore, a part of the second pulley support portion 41 is inserted into the hole 20b, and is further supported by the plate-like members constituting the second pulley support portion 41 (portions having the same shape as the plate-like members 41a and 41b shown in FIG. 2B). The second pulley support portion 41 is supported by the support body 201 by sliding the second pulley support portion 41 with the body 201 interposed therebetween. In this state, the second pulley support portion 41 can be reciprocated in a direction parallel to the y-axis.

  Further, a plate-like member 20c having a spring receiving portion 20d similar to that shown in FIGS. 2C and 2D is connected to the support 201. Moreover, the 2nd pulley support part 41 is provided with the spring receiving part 41g similarly to FIG. 2B. Therefore, by inserting the spring 42 into the spring receiving portion 20d and the spring receiving portion 41g, the spring 42 is held between the second pulley support portion 41 and the plate-like member 20c as shown in FIG. 3B. It can be. Also in this embodiment, the spring 42 is held between the second pulley support portion 41 and the plate-like member 20c in a contracted state. Therefore, the repulsive force of the spring 42 acts as a force that urges the second pulley support portion 41 that can reciprocate in a direction parallel to the y-axis direction to the left side of FIG. 3B.

  As a result, the repulsive force of the spring 42 prevents the second pulley support portion 41 from moving toward the first pulley 30. In this state, the belt 50 is connected to the first pulley 30 and the second pulley. 40, and a tension is applied to the belt 50.

  In the present embodiment, a columnar guide rail 131 extending in a direction parallel to the direction in which the belt 50 extends is attached in the scanner 100. The line sensor 130 includes a mounting portion (not shown) having an inner diameter slightly larger than the outer diameter of the guide rail 131, and the line sensor 130 is installed in the state where the guide rail 131 is mounted on the mounting portion. It can reciprocate along 131.

  Further, a line sensor 130 is attached to the belt 50, and by rotating the first pulley 30, the belt is reciprocated in a direction parallel to the y-axis direction to move the line sensor 130 along the guide rail 131. It can be reciprocated in a direction parallel to the axial direction. That is, in the scanner 100, the line sensor 130 that can read the same width range as the width of the document table 120 (length in the x-axis direction) is moved in the length direction (y-axis direction) of the document table 120. Thus, it is possible to read an arbitrary range within the range of the same size as the document table 120.

  In this configuration, the second pulley support portion 41 includes a contact portion 41f similar to FIG. 2B. That is, the second pulley support portion 41 includes a contact portion 41 f that protrudes from the second pulley support portion 41 in the direction perpendicular to the xy plane and into the movement path of the line sensor 130. Also in this embodiment, since the belt 50 is hung on the first pulley 30 and the second pulley 40, one end of the moving range of the line sensor 130 is on the second pulley 40 side, and the other end is the first pulley 30. Become the side.

  In the present embodiment, since the contact portion 41f protruding from the movement path of the line sensor 130 is formed in the second pulley support portion 41, the line sensor 130 moves from the first pulley 30 side to the second pulley 40 side. In the process of moving, if the end of the line sensor 130 reaches the contact part 41f, the line sensor 130 is restricted so that it cannot move any further. Thus, when the line sensor 130 comes into contact with the contact portion 41f, the force in the separation direction in which the first pulley 30 and the second pulley 40 are separated by the line sensor 130 continues to act on the second pulley support portion 41. . Therefore, even if the driving force for moving the line sensor 130 continues to act on the belt from the motor, the second pulley 40 and the second pulley 40 can be prevented from approaching the first pulley 30. Further, it is possible to prevent the belt 50 from being tensioned. As a result, tooth skipping can be prevented.

  In the present specification, the printer 10 and the scanner 100 are illustrated as devices having a driving mechanism of the driving body, but it is needless to say that the devices having the driving mechanism of the driving body are not limited to these devices. In other words, the device includes two or more pulleys, and a force for tensioning the belt acts on at least one of the pulleys via the pulley support portion, and when the driving body moves to the pulley side, the driving body It may be configured to assist the force for tensioning the belt by contacting the pulley support, and can be applied to various devices. In the above-described embodiment, the first pulley 30, the second pulley 40, and the belt 50 have teeth that mesh with each other. However, the present invention is applied to a configuration in which the belt is hung on a pulley that is not formed with the teeth. It is also possible to apply.

DESCRIPTION OF SYMBOLS 10 ... Printer, 11 ... Insertion port, 12 ... Discharge port, 13 ... Carriage, 13a ... Plate member, 20 ... Support body, 20a, 20b ... Hole, 20c ... Plate member, 20d ... Spring receiving part, 30 ... First DESCRIPTION OF SYMBOLS 1 pulley, 30a ... Flange, 30b ... Cylindrical part, 30c ... Rotating body, 40 ... 2nd pulley, 40a ... Rotating body, 40b ... Rotating shaft, 41 ... 2nd pulley support part, 41a ... Plate-shaped member, 41a-41c ... Plate-like members, 41d, 41e ... Connection part, 41f ... Contact part, 41g ... Spring receiving part, 41h ... Bearing part, 42 ... Spring, 50 ... Belt, 60 ... Motor

Claims (4)

A driving mechanism for driving a driving body attached to the belt by a belt hung on the first pulley and the second pulley;
Conversion that converts a force including a component in a direction from the first pulley side to the second pulley side acting on the driving body into a force that maintains or increases the distance between the first pulley and the second pulley. A drive mechanism comprising means. The first pulley is rotatably supported by a support and is rotationally driven by a motor.
The converting means includes
A second pulley support portion supported by the support body so as to be movable in a direction in which the distance between the second pulley and the first pulley is changed while supporting the second pulley;
The belt is attached to the support and the second pulley support portion, and the belt is stretched from the second pulley to the belt in a state where the belt is hooked on the first pulley and the second pulley. Tension generating means for applying a force to the second pulley support so that a force acts;
The second pulley support portion is provided on the second pulley support portion and contacts the driving body moving from the first pulley side to the second pulley side, thereby acting on the driving body from the first pulley side to the second pulley side. The drive mechanism according to claim 1, further comprising: a contact portion that converts a force including a component in a direction toward the head into a force that maintains or increases a distance between the first pulley and the second pulley. The tension generating means is a spring having one end attached to the support and the other end attached to the second pulley support.
The drive mechanism according to claim 2. The contact portion is a member protruding from the second pulley support portion to the moving path of the drive body.
The drive mechanism according to any one of claims 2 and 3.

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