JP2007085419A - Power transmission mechanism, image reader, image processing device and assembling method of power transmission mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify structure of a power transmission mechanism and to reduce operation sound. <P>SOLUTION: For tension of a looped belt 403 passing over a drive pulley 401 rotating with drive of a motor 406 and a power transmission pulley 402 rotatably provided around an axial center parallel to a rotation axial center of the drive pulley 401, the drive pulley 401 is displaced along a counter direction of the drive pulley 401 and the power transmission pulley 402 by a position adjusting mechanism 404 and a rotation position of the drive pulley 401 is fixed by a fixing mechanism 405 at an arbitral position in an adjustment range by the position adjusting mechanism 404. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission mechanism, an image reading device, an image processing device, and a method for assembling a power transmission mechanism.

  Conventionally, there are various power transmission mechanisms that transmit a driving force of a motor to another member. For example, there is a power transmission mechanism in which a drive gear and other members provided on a drive shaft of a motor are connected via a gear train, and the driving force of the motor is transmitted to the other members via this gear train (for example, , See Patent Document 1 below).

  Further, for example, there is a power transmission mechanism in which a belt is stretched between a driving pulley and a tension pulley provided in a motor, and the driving force of the motor is transmitted to other members via this belt (for example, the following patent document) 2). The technique described in Patent Document 2 includes a belt tension mechanism that applies a predetermined tension to the belt.

Japanese Patent Laid-Open No. 11-165852 JP 2002-340116 A

  However, in the technique described in Patent Document 1 described above, there is a problem that the operation sound due to the tooth contact sound caused by meshing the teeth of each gear constituting the gear train is large. On the other hand, in the technique described in Patent Document 2 described above, it is possible to reduce the operation sound caused by the tooth contact sound, but it is necessary to provide a belt tension mechanism that applies a predetermined tension to the belt. Compared with a power transmission mechanism that transmits the driving force of the motor to other members via the row, there is a problem that the number of parts and the number of manufacturing steps increase, and the manufacturing cost of the power transmission mechanism increases.

  The power transmission mechanism according to the present invention includes a drive pulley that rotates as the motor is driven, a power transmission pulley that is rotatably provided about an axis parallel to the rotation axis of the drive pulley, and the drive pulley. A loop-shaped belt stretched over the power transmission pulley, a position adjustment mechanism capable of displacing the drive pulley along a facing direction of the drive pulley and the power transmission pulley, and adjustment by the position adjustment mechanism And a fixing mechanism that fixes the rotational position of the drive pulley at an arbitrary position within the range.

  Therefore, the position of the drive pulley relative to the power transmission pulley can be displaced along the opposing direction of the drive pulley and the power transmission pulley, and the rotational position of the drive pulley can be fixed at an arbitrary position. Thus, the belt tension can be adjusted only by adjusting the position of the drive pulley relative to the power transmission pulley.

  Further, the position adjusting mechanism in the power transmission mechanism according to the present invention biases the drive pulley in a direction to separate the drive pulley and the power transmission pulley so that the belt has a tension within a predetermined range. It has the contact member with which the biasing member to contact is contacted.

  Therefore, the position of the drive pulley relative to the power transmission pulley can be displaced without directly applying the biasing force applied by the biasing member to the power transmission pulley or the drive pulley. As a result, the belt tension can be adjusted without causing deformation or displacement of the power transmission pulley and the drive pulley.

  Further, the contact member in the power transmission mechanism according to the present invention is provided on a straight line passing through a rotational axis of the drive pulley and the power transmission pulley.

  Therefore, the position of the drive pulley relative to the power transmission pulley can be displaced by displacing the position of the contact member. Thereby, the tension of the belt can be adjusted with a simple configuration.

  Further, the position adjusting mechanism in the power transmission mechanism according to the present invention includes a long hole whose longitudinal direction is the facing direction of the drive pulley and the power transmission pulley, and a pin that is inserted into the long hole and is displaced together with the drive pulley. It has the shape member.

  Therefore, by restricting the displacement position of the pin-like member by the long hole, the position of the drive pulley can be restricted within a range along the facing direction of the drive pulley and the power transmission pulley. This makes it possible to adjust the belt tension while restricting the position of the drive pulley without hindering the displacement of the drive pulley.

  Further, the position adjusting mechanism in the power transmission mechanism according to the present invention is characterized in that the drive pulley can be displaced by sliding the pin-shaped member along the longitudinal direction of the long hole.

  Therefore, by displacing the pin-shaped member within the long hole, the position of the drive pulley can be displaced while being regulated within a range along the facing direction of the drive pulley and the power transmission pulley. This facilitates the position adjustment operation of the drive pulley relative to the power transmission pulley.

  The fixing mechanism in the power transmission mechanism according to the present invention is characterized in that the rotational position of the drive pulley is fixed by fixing the position of the pin-shaped member in the elongated hole.

  Therefore, the position of the drive pulley relative to the power transmission pulley can be displaced without touching the drive pulley, power transmission pulley and belt. This makes it possible to adjust the belt tension without causing damage to the drive pulley, power transmission pulley, or belt caused by touching the drive pulley, power transmission pulley, or belt.

  In the power transmission mechanism according to the present invention, the pin-shaped member is a screw that is screwed into a screw hole provided in the motor or a member fixed to the motor.

  Therefore, the members constituting the position adjusting mechanism and the fixing mechanism are partially overlapped, and the position adjusting mechanism and the fixing mechanism can be downsized and the configuration can be simplified. As a result, it is possible to reduce the size of the power transmission mechanism and facilitate the assembly work.

  In addition, an image reading apparatus according to the present invention includes an optical reading unit that optically reads an image by being driven by the power transmission mechanism described above.

  Therefore, when the image is read by the optical reading unit, the driving force of the motor can be transmitted via the power transmission mechanism. Accordingly, it is possible to reduce the operation sound when the driving force of the motor is transmitted to the optical reading unit, and to accurately operate the optical reading unit to improve the image reading accuracy by the optical reading unit.

  The image processing apparatus according to the present invention is characterized by comprising image processing means for performing image processing on the image data read by the image reading apparatus described above.

  Therefore, image processing is performed using image data with high reading accuracy read by the image reading apparatus. Thereby, the reliability of the image processing result by the image processing apparatus can be improved.

  The power transmission mechanism assembling method according to the present invention includes a drive pulley that rotates as the motor is driven, and can rotate about an axis parallel to the rotation axis of the drive pulley within a rotation plane of the drive pulley. A first step of bridging a loop-shaped belt on the power transmission pulley provided in the first direction, and a direction in which the driving pulley and the power transmission pulley face each other in a state where the belt is bridged by the first step A second step of displacing the drive pulley with respect to the power transmission pulley, and rotation of the drive pulley in a state where a tension within a predetermined range is applied to the belt by the second step. And a third step of fixing the position.

  Therefore, the position of the drive pulley with respect to the power transmission pulley is adjusted along the opposing direction of the drive pulley and the power transmission pulley in a state where the belt is bridged between the drive pulley and the power transmission pulley, and the rotation of the drive pulley is adjusted at the adjusted position. The power transmission mechanism can be assembled by fixing the position. As a result, the assembly work can be facilitated.

  In the power transmission mechanism assembling method according to the present invention, the second step is characterized in that the drive pulley is displaced according to the tension of the belt.

  Therefore, the rotational position of the drive pulley relative to the power transmission pulley can be fixed within a range where the belt tension is optimum. Thus, the tension of the belt can be adjusted when the power transmission mechanism is assembled.

  Further, in the power transmission mechanism assembling method according to the present invention, the first step spans the belt with the drive pulley brought close to the power transmission pulley, and the second step includes the tension of the belt. The drive pulley is displaced so that the drive pulley, which has been moved away from the power transmission pulley to a position where is equal to or greater than the predetermined range, is brought closer to the power transmission pulley to a position where the belt tension is within the predetermined range. It is characterized by making it.

  Accordingly, the belt can be bridged at a position where the operation is easy, and the rotational position of the drive pulley relative to the power transmission pulley can be fixed after the belt is securely meshed with the drive pulley and the power transmission pulley. As a result, the assembly work of the power transmission mechanism can be facilitated and the reliability in the operation after the assembly can be improved during the assembly.

  Exemplary embodiments of a power transmission mechanism, an image reading apparatus, an image processing apparatus, and a method for assembling a power transmission mechanism according to the present invention will be explained below in detail with reference to the accompanying drawings. This embodiment shows an application example to a multifunction machine having a power transmission mechanism, an image reading apparatus, and an image processing apparatus according to the present invention. The power transmission mechanism, the image reading apparatus, and the image processing apparatus in this embodiment are assembled using the power transmission mechanism assembling method according to the present invention.

  FIG. 1 is a perspective view showing an external appearance of a multifunction machine according to an embodiment of the present invention. First, the external appearance of a multifunction machine equipped with a power transmission mechanism according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the multifunction peripheral 100 includes a scanner unit 110 as an image reading device, a printer unit 120, and an operation panel 150. The scanner unit 110 optically reads an image (graphics, text, photo, etc.) of a document and photoelectrically converts the optically read image to generate image data.

  FIG. 2 is a longitudinal side view showing the internal structure of the multifunction peripheral 100. Next, the internal structure of the multifunction peripheral 100 will be described with reference to FIG. As shown in FIG. 2, the scanner unit 110 includes a scanner case 111, a transmissive document light source unit (hereinafter referred to as “TPU unit”) 112, a document table 113 as a document holding unit, a scanner carriage 114, A carriage guide 115. The scanner case 111 has a housing shape and is rotatably connected to the printer case 121 via a hinge (not shown). In the scanner case 111, each member for optically reading data written on a document is stored.

  The TPU unit 112 presses the document placed on the document table 113 against the document table 113 so as to cover the document from above. The TPU unit 112 is provided with a plate-like protective mat (not shown) having a size substantially the same as that of the document table 113 at a portion where the document is pressed. The TPU unit 112 is rotatably connected to the scanner case 111 via a hinge (not shown).

  The document table 113 is a plate-like member formed using an optically transparent glass material or the like, and is fixed so as to close an opening (not shown) formed in the upper part of the scanner case 111. A document is placed on the document table 113 by the user. The document may be an opaque document using paper or the like, or a transparent document using a transparent film or the like.

  The scanner carriage 114 is accommodated in the scanner case 111 and has various members for optically reading an image of a document. The scanner carriage 114 is provided so as to reciprocate along a carriage guide 115 arranged with the sub-scanning direction as a longitudinal direction. The scanner carriage 114 is reciprocated by a drive mechanism (not shown) configured by, for example, a motor (see FIG. 4) and a drive belt connected to the motor.

  Although not shown, the scanner carriage 114 is mounted with a scanning circuit board on which a linear image sensor is mounted, a lens, a mirror, a light source, and the like as members for optically reading an image of a document. The light emitted from the light source mounted on the scanner carriage 114 toward the original is imaged on the light receiving surface of the linear image sensor via the mirror and the lens. In this embodiment, an optical reading unit is realized by each member for optically reading an image of a document, such as a scanning circuit board, a lens, a mirror, and a light source.

  A linear image sensor is an element that photoelectrically converts an optical image formed on the light-receiving surface and outputs an electrical signal corresponding to the amount of light received for each light-receiving element. The light-receiving element such as a photodiode performs main scanning. It is formed by being mounted on the scanning circuit board in a posture arranged in a straight line in the direction.

  Next, the printer unit 120 will be described. The printer unit 120 forms an image on a sheet based on image data transmitted from a PC (personal computer) or the like connected to the multifunction peripheral 100 via a network. As shown in FIG. 2, the printer unit 120 includes a printer case 121, an ASF unit 130, and a printing mechanism unit (see FIG. 3). The ASF unit 130 is provided in the vicinity of the paper feed opening 130 </ b> A, and includes a paper feed roller 131, a paper support plate 132, and a paper feed plate 133.

  The printer case 121 is provided with an opening 121 </ b> A that opens toward the scanner case 111. The opening 121 </ b> A can be exposed by rotating the scanner case 111 in a direction away from the printer case 121. For example, when maintaining each member stored in the scanner case 111. Exposed to. Each member for forming an image on a sheet based on image data is stored in the printer case 121.

  FIG. 3 is a longitudinal side view showing the ASF unit 130 and the printing mechanism section. Next, the ASF unit 130 and the printing mechanism unit will be described with reference to FIG. In the ASF unit 130 described above, the paper feed roller 131 is pivotally supported by the printer case 121 so as to be rotatable in the paper feed direction in the vicinity of the paper feed port 130A. The paper feed roller 131 rotates in response to a driving force from a motor provided in the ASF unit 130 or a motor (not shown), thereby feeding the paper pushed out by the paper feed plate 133 from the paper feed port 130A to the inside of the printer case 121. The sheet is pulled in and conveyed between a print head 144 and a platen 145, which will be described later.

  The paper support plate 132 is a plate-like member formed above the paper feed plate 133 and is connected to the upper end of the paper feed plate 133 by a hinge formed at the lower end of the paper support plate 132 so as to be opened and closed. As shown in FIGS. 2 and 3, when the paper support plate 132 is fed, the front surface of the paper supply plate 133 and the front surface of the paper support plate 132 have the same inclination angle with the front surface open. It is locked in the position to do. The paper support plate 132 supports the back surface of the paper bundle 122.

  When the paper support plate 132 is not fed, the paper support plate 132 can be folded toward the front side of the multifunction peripheral 100 around the hinge formed at the lower end of the paper support plate 132. The paper support plate 132 folded in this way is locked when the upper front surface of the paper support plate 132 comes into contact with the TPU unit 112, thereby closing the space connected to the paper feed port 130A. The sheet feeding plate 133 is a plate-like member provided at a position where the sheet bundle 122 can be supplied to the sheet feeding opening 130 </ b> A, and holds the sheet bundle 122. The sheet feeding plate 133 swings with the rotation of the motor, and pushes the lower end of the sheet bundle 122 toward the sheet feeding port 130A, thereby sliding the sheet to the sheet feeding port 130A.

  The printing mechanism unit 140 includes a printer carriage 141, an ink cartridge 142, a guide rod 143, a print head 144, a platen 145, a paper discharge roller 146, a stacker 147, and the like. The printer carriage 141 stores the ink cartridge 142 in a removable manner. The printer carriage 141 is locked by a belt that is driven by a motor provided in the printing mechanism unit 140, and is supported by the guide rod 143 via the belt as the motor rotates, so that the axial direction of the guide rod 143 is achieved. Reciprocate.

  The ink cartridge 142 is a container in which each color ink is stored, and is detachably stored in the printer carriage 141. The ink stored in the ink cartridge 142 is supplied to the nozzles of the print head 144 through the ink passage. The guide rod 143 is a rod-shaped member fixed to the printer case 121 and supports the printer carriage 141 so as to be slidable in the lateral width direction of the multifunction peripheral 100.

  The print head 144 is provided below the printer carriage 141, and fixes the ink supplied from the ink cartridge 142 to the paper by an inkjet method. The print head 144 is provided with a nozzle for discharging ink, an ink passage, and the like. The print head 144 reciprocates in the axial direction of the guide rod 143 together with the printer carriage 141. In this embodiment, an ink jet printing unit is used, but an electrostatic image forming system using a laser or the like, a sublimation system, an impact system, or the like may be used.

  The platen 145 is a bar-like member that is located below the print head 144 and has a flat surface above it, and is fixed to the printer case 121. The plane formed above the platen 145 is in sliding contact with the paper and positions the paper at a position slightly away from the print head 144.

  The paper discharge roller 146 is provided to be rotatable in the paper discharge direction in the vicinity of the paper discharge port 140A. The paper discharge roller 146 rotates by driving a motor or the like provided in the printing mechanism unit 140, thereby pulling out the printed paper and discharging it from the paper discharge port 140A to the outside of the printer case 121. The paper discharged to the outside of the printer case 121 by the paper discharge roller 146 is deposited on the upper surface of the stacker 147 supported by the printer case 121 so as to be swingable.

  The operation panel 150 is provided on the front side of the printer case 121 and receives various processing requests such as image reading processing and printing processing for the multifunction peripheral 100 when operated by the user. The operation panel 150 is provided with a liquid crystal panel 151, a plurality of push buttons 152, and the like. The liquid crystal panel 151 displays a setting menu, an operation menu, a processing status, and the like. The user requests the MFP 100 for processing by pressing a push button 152 corresponding to the processing request.

  Although not shown, the multifunction device 100 includes a control unit that drives and controls each unit included in the multifunction device 100. The control unit includes a CPU for centrally driving and controlling the scanner unit 110, a CPU for centrally driving and controlling the printer unit 120, and various control programs executed by these CPUs. Is constituted by a ROM that stores the data, a RAM that functions as a work area of the CPU, and the like. For example, the control unit performs predetermined image processing on the image of the document read by the scanner unit 110. For this reason, in the present embodiment, an image processing unit is realized by the control unit, and an image processing apparatus is realized by the multifunction peripheral 100, more specifically, the scanner unit 110.

  FIG. 4 is an exploded perspective view showing each member constituting the power transmission mechanism. Next, the power transmission mechanism will be described in detail with reference to FIG. As shown in FIG. 4, the power transmission mechanism 400 includes a drive pulley 401, a power transmission pulley 402, a belt 403, a position adjustment mechanism 404, and a fixing mechanism 405. The drive pulley 401 is provided on the drive shaft 407 of the motor 406 described above, and rotates around the axis of the drive shaft 407 as the motor 406 is driven.

  The power transmission pulley 402 is held by a holder 408 so as to be rotatable with respect to the holder 408. The holder 408 is a plate-like member formed by press-molding a metal material, and is directly attached to the scanner case 111 so that the rotation axis of the power transmission pulley 402 and the rotation axis of the drive pulley 401 are parallel to each other. Or indirectly fixed. As a result, the power transmission pulley 402 can rotate about an axis parallel to the rotation axis of the drive pulley 401. The belt 403 has a loop shape and is spanned between the drive pulley 401 and the power transmission pulley 402.

  The position adjustment mechanism 404 includes a long hole 409, a screw 410, and a contact member 411. The long hole 409 is formed in the holder 408 such that the opposing direction of the drive pulley 401 and the power transmission pulley 402 is the longitudinal direction. The screw 410 is inserted into the long hole 409 so as to be slidable within the long hole 409, and the tip portion is screwed into a screw hole (see FIG. 5) provided in the motor 406.

  As a result, the screw 410 can be displaced together with the drive pulley 401. That is, in the position adjustment mechanism 404, the screw 410 inserted in the long hole 409 is slid along the longitudinal direction of the long hole 409, so that the driving pulley 401 and the power transmission pulley 402 are opposed to each other. The power transmission pulley 402 can be displaced. In this embodiment, a pin-shaped member is realized by the screw 410.

  The contact member 411 is located on the holder 408 on a straight line passing through the rotational axes of the drive pulley 401 and the power transmission pulley 402 and provided on the opposite side of the power transmission pulley 402 with the drive pulley 401 in between. It has been. Although details will be described later, the urging member (see FIG. 6) is brought into contact with the contact member 411 when the power transmission mechanism 400 is assembled.

  The fixing mechanism 405 includes a screw hole (see FIG. 5) provided in the motor plate 420 to which the motor 406 is fixed, a long hole 409, and a screw 410. The fixing mechanism 405 is configured such that the screw 410 is screwed into the screw hole through the long hole 409 in a state where the screw 410 is positioned at an arbitrary position in the long hole 409, thereby The rotational position is fixed at an arbitrary position within the adjustment range by the position adjustment mechanism 404.

  In addition, although detailed illustration is abbreviate | omitted, the motor 406 and the motor plate 420 are being fixed by the screw | thread 421 via the elastic member, and are integrated as the motor unit 422. The screw 410 is screwed into the screw hole to fix the holder 408 and the motor plate 420, thereby fixing the holder 408 and the motor unit 422.

  In addition, the holder 408 is provided with a gear 412 that rotates around the rotation axis of the power transmission pulley 402 as the power transmission pulley 402 rotates. The outer peripheral surface of the gear 413 is in contact with the outer peripheral surface of the gear 412. The gear 413 is rotatably supported by a support shaft 414 provided on the holder 408. The gear 413 is integrally provided with a pulley 415 that rotates together with the gear 413. A driving belt (not shown) related to driving of the scanner carriage 114 described above is bridged over the pulley 415.

  FIG. 5 is an explanatory diagram for explaining assembly of the power transmission mechanism 400. Next, a method for assembling the power transmission mechanism 400 will be described with reference to FIG. When the power transmission mechanism 400 is assembled, first, the motor 406 is brought into contact with the holder 408 to which the power transmission pulley 402 and the gear 412 are attached. The motor 406 makes the holder 408 contact the holder 408 from the side opposite to the power transmission pulley 402. The holder 408 has a through hole 501 into which the drive shaft 407 of the motor 406 is inserted. The through hole 501 is formed so as to penetrate the holder 408 along the thickness direction of the holder 408.

  Next, the belt 403 is bridged between the drive pulley 401 and the power transmission pulley 402. At this time, the belt 403 is bridged in a state where the drive pulley 401 is brought close to the power transmission pulley 402. Here, the first step is realized. Then, the screw 410 is screwed into the screw hole 502 through the long hole 409 in a state where the belt 403 is bridged between the drive pulley 401 and the power transmission pulley 402. At this time, the screw 410 is screwed so that the screw 410 can slide in the long hole 409. That is, the holder 408 at this stage is displaceable with respect to the motor 406.

  Subsequently, the tension of the belt 403 is adjusted. In this embodiment, the holder 408 is displaced in a state where the belt 403 is stretched between the drive pulley 401 and the power transmission pulley 402, and the rotational position of the drive pulley 401 is displaced with respect to the power transmission pulley 402. The tension of the belt 403 is adjusted. In adjusting the tension of the belt 403, a jig and an urging mechanism (see FIG. 6) are used.

  FIG. 6 is an explanatory diagram for explaining the adjustment of the tension of the belt 403. Next, adjustment of the tension of the belt 403 will be described with reference to FIG. In FIG. 6, the jig 600 includes a fixing part 610 and a guide part 620. The fixing portion 610 includes a holding recess 611 and a fixing member 612, and the motor unit 422 fitted in the holding recess 611 is pressed by the fixing member 612 to fix the position of the motor 406. The holding recess 611 is provided on the fixing substrate 613. The fixing substrate 613 is fixed on a base 614 that supports the jig 600 as a whole. The fixing member 612 presses the motor 406 fitted in the holding recess 611 against the base 614 side.

  The guide part 620 includes a guide groove 621 and a restriction member 622. The guide groove 621 is provided in the fixing substrate 613 and extends along the facing direction of the drive pulley 401 and the power transmission pulley 402 in a state where the motor unit 422 is fitted in the holding recess 611. The restriction member 622 restricts the position of the holder 408 so that the holder 408 can be displaced along the guide groove 621.

  The biasing mechanism 630 includes a biasing member 631 and a biasing force applying unit (not shown). The biasing member 631 is brought into contact with the contact member 411 of the holder 408 in a state where the motor unit 422 is fixed by the jig 600. The biasing force applying means applies a biasing force in a direction in which the biasing member 631 is brought into contact with the contact member 411 to the biasing member 631. The urging force applying means includes a detecting means for detecting a force that urges the contact member 411 by the urging member 631. By using the detection means, the tension of the belt 403 can be indirectly measured.

  In this embodiment, a biasing force is applied to the contact member 411 by the biasing mechanism 630 via the biasing member 631 while the position of the motor unit 422 is fixed by the jig 600. As a result, the holder 408 is displaced in a direction away from the biasing mechanism 630, and the holder 408 is displaced in a direction away from the power transmission pulley 402 along with the displacement. When applying the urging force, the holder 408 is displaced so that the drive pulley 401 and the power transmission pulley 402 are separated from each other to a position where the tension of the belt 403 is equal to or greater than a predetermined range by using a detection unit. In accordance with the tension, the holder 408 is displaced to a position where the tension of the belt 403 is within a predetermined range. Here, the second step is realized.

  In FIG. 6, since the motor unit 422 is fixed and the holder 408 is displaced, the power transmission pulley 402 is apparently displaced with respect to the drive pulley 401. Incidentally, the position of the power transmission pulley 402 inside the scanner case 111 is fixed in order to drive the scanner carriage 114. Therefore, the drive pulley 401 is displaced with respect to the power transmission pulley 402 in the entire multifunction peripheral 100.

  FIG. 7 is a plan view (part 1) showing the power transmission mechanism 400, and FIG. 8 is a plan view (part 2) showing the power transmission mechanism 400. Next, adjustment of the tension of the belt 403 will be further described with reference to FIGS. FIG. 7 shows a state in which the drive pulley 401 is brought close to the power transmission pulley 402 until the tension of the belt 403 becomes a predetermined range or more. FIG. 8 shows a state in which the drive pulley 401 is moved away from the power transmission pulley 402 until the tension of the belt 403 is within a predetermined range.

  As can be seen from FIGS. 7 and 8, in this embodiment, the tension of the belt 403 can be adjusted within a predetermined range by sliding the screw 410 along the longitudinal direction of the long hole 409. By adjusting the tension of the belt 403 within a predetermined range, the driving pulley 401, the power transmission pulley 402, and the belt 403 are meshed to such an extent that the rotational force of the driving pulley 401 can be accurately transmitted to the power transmission pulley 402. Can do.

  Finally, the screw 410 is screwed into the screw hole 502 at a position where the tension applied to the belt 403 is within a predetermined range (see FIG. 8). As a result, the position of the holder 408 relative to the motor unit 422 is fixed, and the rotational position of the drive pulley 401 relative to the power transmission pulley 402 is fixed. Here, the third step is realized.

  As described above, according to this embodiment, the position of the drive pulley 401 with respect to the power transmission pulley 402 is determined with respect to the drive pulley 401 and the power transmission pulley in a state where the belt 403 is bridged between the drive pulley 401 and the power transmission pulley 402. The tension of the belt 403 can be adjusted by displacing along the direction facing the surface 402 and fixing the rotational position of the drive pulley 401 at an arbitrary position. That is, the tension of the belt 403 can be adjusted only by adjusting the position of the drive pulley 401 with respect to the power transmission pulley 402.

  Therefore, the driving force of the motor 406 can be transmitted to the scanner carriage 114 via the belt 403 without providing a belt tension mechanism for applying tension to the belt 403. As a result, the number of components and the number of assembly steps of the power transmission mechanism 400 can be reduced to reduce the manufacturing cost, and the operation sound when the driving force of the motor 406 is transmitted to the scanner carriage 114 can be reduced.

  Further, according to this embodiment, the urging force of the urging member 631 is not directly applied to the power transmission pulley 402 when the power transmission mechanism 400 is assembled. The tension of the belt 403 can be adjusted without generating it. As a result, it is possible to prevent the occurrence of malfunctions such as malfunctions due to misalignment, and to provide a power transmission mechanism 400 with high reliability in operation.

  Further, according to this embodiment, the urging force of the urging member 631 is applied to the abutting member 411 provided integrally with the holder 408, and the holder 408 is slid to indirectly position the power transmission pulley. Therefore, the tension of the belt 403 can be adjusted with a simple configuration. Here, since the contact member 411 is provided on a straight line passing through the rotation axis of the drive pulley 401 and the power transmission pulley 402, the urging force of the urging member 631 can be transmitted efficiently and reliably. .

  In this embodiment, the contact member 411 to which the urging force of the urging member 631 is applied is provided integrally with the holder 408, but the present invention is not limited to this. A contact member may be provided on any member constituting the motor unit 422 such as the motor 406 or the motor plate 420. Also in this case, by applying the urging force of the urging member 631 to the abutting member, the drive pulley 401 can be displaced with respect to the power transmission pulley 402, and the drive pulley 401 is deformed or displaced. The tension of the belt 403 can be adjusted.

  Further, according to this embodiment, the displacement position of the screw 410 is regulated by the long hole 409 so that the position of the drive pulley 401 is within a range along the facing direction of the drive pulley 401 and the power transmission pulley 402. Can be regulated. That is, the position of the drive pulley 401 can be indirectly regulated without directly regulating it. Thereby, when the power transmission mechanism 400 is assembled, the position of the drive pulley 401 relative to the power transmission pulley 402 can be displaced within a predetermined range without making the operator particularly aware of it.

  Further, according to this embodiment, when the power transmission mechanism 400 is assembled, the screw 410 is displaced within the long hole 409, so that the position of the drive pulley 401 can be driven without making the operator particularly conscious. The pulley 401 and the power transmission pulley 402 can be displaced while being regulated within a range along the facing direction. As a result, the position adjustment work of the drive pulley 401 with respect to the power transmission pulley 402 can be facilitated.

  Further, according to this embodiment, by applying the biasing force of the biasing member 631 to the contact member 411 and sliding the holder 408, the position of the power transmission pulley is indirectly displaced, and the long hole 409 is also displaced. By fixing the position of the screw 410, the rotational position of the drive pulley 401 can be fixed. Therefore, the position of the drive pulley 401 relative to the power transmission pulley 402 can be displaced and fixed without touching the drive pulley 401, the power transmission pulley 402, and the belt 403. Thus, the tension of the belt 403 can be adjusted without causing damage to the drive pulley 401, the power transmission pulley 402, or the belt 403 due to touching the drive pulley 401, the power transmission pulley 402, or the belt 403.

  Further, according to this embodiment, the screw 410 in the long hole 409 is screwed into the screw hole 502 provided in the motor plate 420 in the motor unit 422, thereby fixing the position of the drive pulley 401 with respect to the power transmission pulley 402. Therefore, the members constituting the position adjustment mechanism 404 and the fixing mechanism 405 are partially overlapped, so that the position adjustment mechanism 404 and the fixing mechanism 405 can be downsized and the configuration can be simplified. As a result, the power transmission mechanism 400 can be miniaturized and the assembly work can be facilitated.

  Also, according to this embodiment, when the scanner unit 110 reads an image of a document, the driving force of the motor 406 is transmitted to the scanner carriage 114 by the power transmission mechanism 400 described above. As a result, it is possible to improve the reading accuracy of the original image by reducing the operation sound at the time of reading the image and reliably transmitting the driving force of the motor 406 to the scanner carriage 114. In the printer unit 120, an image is formed on a sheet using image data with high accuracy, so that an image with high reproducibility with respect to a document image can be formed.

  Further, according to this embodiment, in the state where the belt 403 is laid over the drive pulley 401 and the power transmission pulley 402, the position of the drive pulley 401 with respect to the power transmission pulley 402 is opposed to the drive pulley 401 and the power transmission pulley 402. The power transmission mechanism 400 can be assembled by adjusting along the direction and fixing the rotational position of the drive pulley 401 at the adjusted position. As a result, the assembly can be performed with a small number of processes, and the assembly work can be facilitated.

  Further, according to this embodiment, the drive pulley 401 is fixed at a position where the tension of the belt 403 falls within a predetermined range in accordance with the tension of the belt 403 detected by the detecting means described above. Thus, when the power transmission mechanism 400 is assembled, the tension of the belt 403 is adjusted in parallel with the assembly work, thereby reducing the number of steps in the entire assembly process of the power transmission mechanism 400 and facilitating the assembly work. Can do.

  Further, according to this embodiment, when the power transmission mechanism 400 is assembled, the belt 403 is bridged with the drive pulley 401 close to the power transmission pulley 402, thereby facilitating the belt 403 bridging work. Can do. Then, the position of the driving pulley 401 is fixed after the driving pulley 401 and the power transmission pulley 402 are moved away to a position where the tension of the belt 403 becomes a predetermined range or more, whereby the belt 403 is fixed to the driving pulley 401 and the power transmission pulley 402. Thus, the rotational position of the drive pulley 401 can be fixed in a state where the drive pulley 401 is securely engaged. As a result, it is possible to facilitate the assembling work of the power transmission mechanism 400 and to improve the reliability in the operation after assembling.

1 is a perspective view showing an external appearance of a multifunction machine according to an embodiment. FIG. 3 is a vertical side view showing the internal structure of the multifunction machine. FIG. 3 is a longitudinal side view showing an ASF unit and a printing mechanism unit. The disassembled perspective view which shows each member which comprises a power transmission mechanism. Explanatory drawing explaining the assembly of a power transmission mechanism. Explanatory drawing explaining adjustment of the tension | tensile_strength of a belt. The top view which shows a power transmission mechanism (the 1). The top view which shows a power transmission mechanism (the 2).

Explanation of symbols

401 Drive pulley, 402 Power transmission pulley, 403 belt, 404 Position adjustment mechanism, 405 Fixing mechanism, 406 Motor

Claims (12)

A drive pulley that rotates as the motor is driven;
A power transmission pulley provided to be rotatable about an axis parallel to the rotation axis of the drive pulley;
A loop belt spanned between the drive pulley and the power transmission pulley;
A position adjusting mechanism capable of displacing the drive pulley along a facing direction of the drive pulley and the power transmission pulley;
A fixing mechanism for fixing the rotational position of the drive pulley at an arbitrary position within an adjustment range by the position adjusting mechanism;
A power transmission mechanism comprising: The position adjustment mechanism is
A contact member that abuts a biasing member that biases the drive pulley in a direction to separate the drive pulley and the power transmission pulley so that the belt has a tension within a predetermined range; The power transmission mechanism according to claim 1, wherein: The contact member is
The power transmission mechanism according to claim 2, wherein the power transmission mechanism is provided on a straight line passing through a rotation axis of the drive pulley and the power transmission pulley. The position adjustment mechanism is
4. The device according to claim 1, further comprising: a long hole whose longitudinal direction is an opposing direction of the drive pulley and the power transmission pulley; and a pin-shaped member that is inserted into the long hole and is displaced together with the drive pulley. The power transmission mechanism as described in one. The position adjustment mechanism is
The power transmission mechanism according to claim 4, wherein the drive pulley can be displaced by sliding the pin-shaped member along the longitudinal direction of the long hole. The fixing mechanism is
The power transmission mechanism according to claim 4 or 5, wherein the rotational position of the drive pulley is fixed by fixing the position of the pin-shaped member in the elongated hole. The pin-shaped member is
The power transmission mechanism according to any one of claims 4 to 6, wherein the power transmission mechanism is a screw screwed into a screw hole provided in the motor or a member fixed to the motor.   An image reading apparatus comprising an optical reading unit that optically reads an image by being driven by the power transmission mechanism according to claim 1.   An image processing apparatus comprising image processing means for performing image processing on image data read by the image reading apparatus according to claim 8. A loop belt in a drive pulley that rotates as the motor is driven, and a power transmission pulley that is provided to be rotatable about an axis parallel to the rotation axis of the drive pulley within a rotation plane of the drive pulley. The first step of bridging
A second step of displacing the drive pulley with respect to the power transmission pulley along a facing direction of the drive pulley and the power transmission pulley in a state where the belt is stretched over by the first step;
A third step of fixing the rotational position of the drive pulley in a state in which a tension within a predetermined range is applied to the belt by the second step;
A method for assembling a power transmission mechanism, comprising: The second step includes
The method of assembling the power transmission mechanism according to claim 10, wherein the drive pulley is displaced in accordance with a tension of the belt. The first step includes
Span the belt with the drive pulley close to the power transmission pulley,
The second step includes
The drive pulley, which has been moved away from the power transmission pulley to a position where the belt tension is equal to or greater than the predetermined range, is brought close to the power transmission pulley to a position where the belt tension is within the predetermined range. 12. The assembly method for a power transmission mechanism according to claim 11, wherein the drive pulley is displaced.

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