JP2004085890A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of easily adjusting the tension of an endless belt for transmitting driving to a carriage driving mechanism through a reduction gear from a driving source with a simple configuration. <P>SOLUTION: A 2nd bracket 66 supporting the reduction gear 61 is disposed to slide in a direction where a first timing belt 62 is tensioned on a first bracket 64 supporting a stepping motor 60, and a spring 68 is stretched and laid between the bracket 64 and the bracket 66, and the bracket 66 is fixed on the bracket 64 while being biased by the spring 68 in the direction where the belt 62 is tensioned. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus in which a driving force is transmitted from a driving source to a carriage driving mechanism via a reduction gear by an endless belt, and the carriage scans a document. The present invention relates to an image reading apparatus capable of applying a suitable tension to an endless belt and extending a drive by stretching a spring between a bracket supporting a reduction gear and fixing the spring.
[0002]
[Prior art]
Scanners, facsimile machines, copiers, etc. scan an original such as paper placed on platen glass with a light source and a reflection mirror below the platen glass and scan the original with an imaging unit such as a CCD. Some are equipped with an image reading device for reading an image. As such a conventional image reading apparatus, for example, a full-rate carriage including a light source for irradiating the original with light and a reflection mirror for reflecting the reflected light from the original in a predetermined direction, and a reflection from the full-rate carriage A half-rate carriage having a reflection mirror for guiding light to an imaging unit such as a CCD is provided so as to be scannable along the guide rail, and a half-rate carriage that scans the full-rate carriage and the half-rate carriage by a wire driving mechanism is provided. is there.
[0003]
The wire driving mechanism has a configuration in which a driving force is transmitted from a driving source such as a stepping motor, and a configuration in which a reduction gear is interposed when driving is transmitted from the driving source to the wire driving mechanism. is there. In such a configuration, an endless belt is stretched between the drive shaft of the drive source and the reduction gear and between the reduction gear and the drive shaft of the wire drive mechanism to transmit the driving force. The full-rate carriage is scanned by the driving force transmitted in this manner. When the stepping motor is used as a driving source, the scanning is performed based on the number of pulses applied to the stepping motor. Therefore, in order to maintain good image reading accuracy, the drive transmission from the drive source to the wire drive mechanism needs to be accurate. Therefore, it is necessary that the endless belt for transmitting the drive is appropriately tensioned and is stretched so as not to cause slippage or the like during the transmission of the drive.
[0004]
[Problems to be solved by the invention]
Conventionally, the adjustment of the tension of the endless belt has been performed by adjusting the mounting position of the drive source. However, in this method, the tension of the endless belt stretched between the reduction gear and the wire drive mechanism cannot be adjusted. For example, even when the tension of the endless belt between the drive source and the reduction gear is adjusted in a state where the endless belt between the reduction gear and the wire drive mechanism is loosened, the endless belt between the reduction gear and the wire drive mechanism is thereafter tensioned. As a result, the position and the like of the reduction gear slightly change, so that it is necessary to adjust the tension of the endless belt between the drive source and the reduction gear again. Further, in order to achieve good drive transmission by mutually adjusting the tension of the two endless belts as described above, a high level of skill is required for the worker, the work is troublesome, and the installation and maintenance are performed. There is a disadvantage that the burden on the user is increased as a cost for inspection and the like.
[0005]
On the other hand, there is also a method in which a roller or the like is circumscribed to each endless belt between the reduction gear and the wire drive mechanism and between the drive source and the reduction gear, and the endless belt is pressed by the roller to apply tension. However, if a roller, a biasing means, or the like is provided for each endless belt, the size of the drive transmission mechanism becomes large, and thus there is a disadvantage that it is disadvantageous in securing an installation space and in reducing the size of the image reading apparatus. .
[0006]
The present invention has been made in view of these points, and the tension of an endless belt for transmitting drive from a drive source to a carriage drive mechanism via a reduction gear can be easily adjusted with a simple configuration. It is an object of the present invention to provide an image reading apparatus capable of performing the above.
[0007]
[Means for Solving the Problems]
In the image reading apparatus according to the present invention, the first endless belt is wound between the drive shaft of the drive source and the reduction gear, and the second endless belt is wound between the reduction gear and the drive shaft of the carriage drive mechanism. By being bridged, the driving force of the driving source is transmitted to the carriage driving mechanism via the reduction gear, and in the image reading apparatus in which the carriage scans the document, the driving force is reduced by the first bracket supporting the driving source. A second bracket supporting the gear is slidably provided in a direction to tension the first endless belt, a spring is stretched between the first bracket and the second bracket, and the first endless belt is tensioned by the spring. The second bracket is fixed to the first bracket in a state where the second bracket is urged in the direction in which the second bracket is urged. In a state in which the second bracket is slidable, the second bracket moves in a direction of tensioning the first endless belt by the biasing force of the spring, and at a position where the biasing force of the spring and the tension of the first endless belt are balanced. By fixing the second bracket, tension by the urging force of the spring can be applied to the first endless belt.
[0008]
Further, according to the present invention, the first bracket is provided on the apparatus main body so as to be slidable in a direction to tension the second endless belt, and a spring is stretched between the first bracket and the apparatus main body. (2) The first bracket is fixed to the apparatus main body in a state where the endless belt is urged in the direction of tensioning. In a state in which the first bracket is slidable, the first bracket is moved in a direction of tensioning the second endless belt by the biasing force of the spring, and at a position where the biasing force of the spring and the tension of the second endless belt are balanced. By fixing the first bracket, tension can be applied to the second endless belt by the urging force of the spring.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an image reading apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings. Note that the image reading apparatus according to the present embodiment is merely an example of the present invention, and the configuration of the present invention is not limited to the image reading apparatus.
[0010]
FIG. 1 is a schematic perspective view showing an external appearance of an upper part of a multi-function facsimile machine 1 including an image reading apparatus 100 according to an embodiment of the present invention. As shown in the figure, the copy / facsimile multifunction peripheral 1 includes a reading table 3 on which a platen glass 2 on which a document to be read is placed is arranged, and a document for pressing the document onto the platen glass 2 and fixing the document. A press cover 4 and an operation panel 5 for inputting the start of reading of a document and the like are provided. The image reading apparatus 100 described below is provided in the casing 6 of the reading table 3 and reads an image of a document from below the platen glass 2.
[0011]
Although not shown in the figure, the copy / facsimile multifunction peripheral 1 includes a paper feeding unit that supplies recording paper for recording a read image, an image recording unit that records an image on recording paper, and an image recording unit. The copy / facsimile multifunction peripheral 1 is also an example of a device including the image reading device according to the present invention, and the image recording unit and the like have an arbitrary configuration. Of course.
[0012]
FIG. 2 is a schematic perspective view showing an external configuration of the image reading apparatus 100. As shown in the figure, the image reading apparatus 100 includes a full-rate carriage 101 and a half-rate carriage 102, which are scanned below the platen glass 2 in a direction parallel to the original reading surface, and a full-rate carriage 101 and a half-rate carriage 102. Guide rails 103 that support both ends of each of the upper and lower stages and guide them in the scanning direction, and a driving force that is provided inside the guide rails 103 to scan the full rate carriage 101 and the half rate carriage 102 Drive mechanism (carriage drive mechanism) 104 that transmits light, an image forming unit 105 that converts reflected light from an original into an electric signal, and a drive unit 106 that applies a driving force to the wire drive mechanism 104. Things.
[0013]
FIG. 3 is a front view showing a main configuration of a full rate carriage 101, a half rate carriage 102, and a wire drive mechanism 104. As shown in FIGS. 2 and 3, the full rate carriage 101 is attached to the carriage body 10. A light source 11 for irradiating the original with light, and a reflection mirror 12 for reflecting the reflected light R1 from the original in the scanning direction and guiding the reflected light R1 to the half-rate carriage 102. The carriage main body 20 is provided with two reflection mirrors 21 and 22 for guiding the reflected light R2 from the full rate carriage 101 to the imaging unit 105. Although not shown in detail in the figure, the imaging unit 105 includes a converging lens that converges the reflected light R3 from the half-rate carriage 102, and a charge-coupled device (Charge Couple Device) that converts the converged light into an electric signal. , Hereinafter referred to as “CCD”).
[0014]
The full-rate carriage 101 and the half-rate carriage 102 move under the platen glass 2 in parallel with the original to scan the image of the original, and light is emitted from the light source 11 of the full-rate carriage 101 to the original. R1 is reflected by the reflecting mirror 12 as reflected light R2 in the horizontal direction, further reflected vertically downward by the reflecting mirror 21 of the half-rate carriage 102, and then reflected by the reflecting mirror 22 as reflected light R3 in the horizontal direction. Accordingly, the light is guided to the image forming unit 105, and the image is formed by the CCD.
[0015]
As shown in FIG. 2, the guide rail 103 is provided in a pair at both ends of the full-rate carriage 101 and the half-rate carriage 102. Each of the rate carriages 102 is guided in the scanning direction. The first support 30 for supporting the full-rate carriage 101 and the second support 31 for supporting the half-rate carriage 102 are configured in two upper and lower stages as shown by a dotted line in FIG. 30 is provided over substantially the entire area in the scanning direction, whereas the second support 31 is provided slightly longer than substantially half in the scanning direction.
[0016]
As shown in FIG. 2, a pair of wire driving mechanisms 104 are provided inside the guide rail 103 at both ends of the full rate carriage 101 and the half rate carriage 102, respectively. FIG. 3 shows a wire driving mechanism 104 on the front side of the pair, and as shown in FIG. 3, a wire 40 wound around the full rate carriage 101 and the half rate carriage 102 in the scanning direction. A loop is formed.
[0017]
More specifically, one end of a wire 40 is fixed to a clamp 41 provided at the base end in the scanning direction, and the wire 40 extends in the forward direction from the clamp 41 and is pivotally attached to the main body of the half-rate carriage 102. It is wound around the supported idler pulley 42 by a half turn and extends in the opposite direction. Further, the wire 40 is wound around the driven pulley 43 rotatably fixed below the clamp 41 by a half turn, and extends in the forward direction again. A driven pulley 44 is also rotatably fixed to the leading end in the scanning direction, and a driving pulley 45 is disposed diagonally below and in front of the driven pulley 44 and extends in a forward direction from the driven pulley 43. The wound wire 40 is wound around the driving pulley 45 for one turn or more, and then is wound around the driven pulley 44 for a half turn and extends in the opposite direction. Further, the wire 40 is wound around the idler pulley 42 again by a half turn, extends in the forward direction, and is tensioned by the wire tensioning mechanism 46 formed at the distal end of the second support portion 31. It is fixed at. That is, the hook provided at the other end of the wire 40 is locked by the connecting member 47, and the connecting member 47 is attached to the distal end of the second support portion 31 in a state where the tension of the spring (tension spring) 48 is applied. It is fastened with bolts and the like. At a predetermined position between the driven pulley 44 and the idler pulley 42, the carriage main body 10 of the full rate carriage 101 is fixed to the wire 40 by the wire clamp mechanism 18.
[0018]
When a driving force is applied to the wire loop configured as described above by the rotation of the driving pulley 45, the driving pulley 45 rotates clockwise, so that the full-rate carriage 101 and the half-rate carriage 102 are scanned rightward. When the drive pulley 45 rotates counterclockwise, the full rate carriage 101 and the half rate carriage 102 are scanned leftward. The scanning of the half-rate carriage 102 is performed at approximately half the scanning speed of the full-rate carriage 101. As shown in FIG. 3, the scanning is performed from the base end in the scanning direction to the front end in the scanning direction. While the full-rate carriage 101 is scanned over the scanning distance L1, the half-rate carriage 102 is scanned by about half the scanning distance L2. Although not shown in the figure, the guide rail 103, the clamp 41, and the driven pulleys 43 and 44 are fixed to appropriate places such as the main body of the image reading apparatus 100 by fixing means such as bolts.
[0019]
As shown in FIG. 2, the drive unit 106 includes a stepping motor 60 and a reduction gear 61 that rotate by a predetermined angle with respect to one pulse, and includes a portion between the stepping motor 60 and the reduction gear 61, and Timing belts 62 and 63 are respectively stretched between the drive pulley 45 and the drive shaft 45 a so that the rotation of the stepping motor 60 is transmitted to the drive pulley 45 via the reduction gear 61. The rotation speed and the like of the stepping motor 60 are controlled by a control unit (not shown), whereby the scanning range and the like of the full rate carriage 101 are controlled.
[0020]
Hereinafter, the driving unit 106 will be described in more detail. FIG. 4 is a perspective view of the drive unit 106, FIG. 5 is an exploded perspective view of the drive unit 106, and FIG. 6 is an enlarged rear view of the drive unit 106.
As shown in the figure, the stepping motor 60 is supported by a first bracket 64 fixed to a base or the like of the image reading device 100. A pulley 65 is provided at the tip of the drive shaft 60 a of the stepping motor 60, and a first timing belt (endless belt) 62 is stretched between the pulley 65 and the reduction gear 61. .
[0021]
The first bracket 64 is a sheet metal that has been punched and bent. It comprises a motor support portion 641 for supporting, and a bracket fixing portion 642 projecting from the motor support portion 641 in a substantially horizontal direction and fixing the second bracket 66. As shown in FIG. 2, the first bracket 64 is provided with the stepping motor 60 and the reduction gear 61 between the guide rails 103 and at a position that does not interfere with the optical path of the reflected light from the document or the scanning of the full rate carriage 101. It is preferable to reduce the size as much as possible in consideration of the supporting position of the stepping motor 60, the distance between the stepping motor 60 and the reduction gear 61, and the like so that they can be arranged.
[0022]
Four long holes 643 long in the tensioning direction of the second timing belt 63 are formed in the base 640, and two of the long holes 643 are provided with screws provided on a base or the like of the image reading apparatus 100. A screw 83 that is screwed into the hole 80 is inserted, and the remaining two long holes 643 are engaged with the engaging projections 81 provided on the substrate or the like. When the elongated hole 643 engages with the engaging projection 81, the first bracket 64 is roughly positioned while being slidable in the tensioning direction of the second timing belt 63 within the range of the elongated hole 643. When the screw 83 is inserted into the elongated hole 643 and screwed into the screw hole 80, the base 640 is tightened, and the first bracket 64 can be fixed to the base or the like of the image reading apparatus 100. I have.
[0023]
The motor support 641 is provided with a shaft insertion hole 644 for inserting the drive shaft 60a of the stepping motor 60 and a spring retaining hole 645. The drive shaft 60 a of the stepping motor 60 is inserted through the shaft insertion hole 644 so as to be parallel to the axis of the reduction gear 61. The spring retaining hole 645 corresponds to the spring retaining portion 82 provided on the base or the like of the image reading apparatus 100, and is formed at an end near the base 640, and has a hook-like tip portion of the spring 67. Can be hooked. The spring retaining portion 82 is provided at a position opposite to the side on which the reduction gear 61 is mounted, and the corresponding spring retaining hole 645 is also provided on the motor supporting portion 641 on the spring retaining portion 82 side. It is perforated on the side edge. The spring 67 is hooked between the spring hooking hole 645 and the spring hooking portion 82, and a spring 67 is stretched between the apparatus main body of the image reading apparatus 100 and the first bracket 64. The spring 67 is a coiled tension spring.
[0024]
The bracket fixing portion 642 is provided with a screw hole 646 and an engagement protrusion 647, and a spring retaining portion 648 and a notch 649. The upper end of the bracket fixing portion 642 is bent in the horizontal direction, and the screw hole 646 and the engagement protrusion 647 are provided in the horizontal plane. The screw holes 646 and the engagement protrusions 647 are for roughly positioning and tightening the second bracket 66, similarly to the screw holes 80 and the engagement protrusions 81. The spring retaining portion 648 is a protruding piece protruding horizontally from the lower end on the distal end side of the bracket fixing portion 642, and has a substantially V-shape so that the hook-shaped distal end portion of the spring 68 can be retained. A notch is formed. On the other hand, the cutout portion 649 is formed by cutting out a position corresponding to the horizontal position of the spring hooking portion 648 by a predetermined length on the base end side of the bracket fixing portion 642, and forms a pair with the spring hooking portion 648. The spring engaging portion 661 of the second bracket 66 for engaging the spring 68 is loosely fitted. The notch length of the notch 649 is set in consideration of the sliding movement width of the second bracket 66. Further, the engagement projection 647 may be a projection formed by punching a sheet metal or the like.
[0025]
Similarly to the first bracket 64, the second bracket 66 is a sheet metal that has been punched and bent. The upper end of the second bracket 66 is bent in the horizontal direction. A slot 660 is drilled. A screw 83 that is screwed into a screw hole 646 provided in the bracket fixing portion 642 of the first bracket 64 is inserted into the two long holes 660, and the remaining two long holes 660 are provided in the fixing portion 642. The engaging projection 647 is engaged with the engaging projection 647. When the elongated hole 660 is engaged with the engagement projection 647, the second bracket 66 is roughly positioned while being slidable in the tension direction of the first timing belt 62 within the elongated hole 660. When the screw 83 is inserted into the long hole 660 and screwed into the screw hole 647, the second bracket 66 is tightened with the fixing portion 642 and can be fixed to the first bracket 64. . The spring engaging portion 661 is a protruding piece protruding in a horizontal direction from a lower end portion on the side of the stepping motor 60 of the second bracket 66, that is, on the right side of the drawing, so that a hook-shaped tip portion of the spring 68 can be engaged. Is formed with a substantially V-shaped cut. When the second bracket 66 is positioned on the bracket fixing portion 642 of the first bracket 64, the spring retaining portion 661 is loosely fitted to the notch 649 and forms a pair with the spring retaining portion 648. Note that the screw 83 is an example of a fixture, and it is of course possible to use a tapping screw or another fixture such as a bolt and a nut.
[0026]
A reduction gear 61 is journaled on the outer surface of the second bracket. The reduction gear 61 has a large-diameter pulley 610 and a small-diameter pulley 611 arranged on the same axis, and a first pulley 65 is provided between the pulley 65 provided on the drive shaft 60 a of the stepping motor 60 and the large-diameter pulley 610. The timing belt 62 is stretched, and the second timing belt 63 is stretched between the pulley 69 provided on the drive shaft 45 a of the drive pulley 45 and the small-diameter pulley 611 to rotate the drive shaft 60 a of the stepping motor 60. The speed is reduced by the reduction gear 61 and transmitted to the drive shaft 45 a of the drive pulley 45.
[0027]
The first timing belt 62 and the second timing belt 63 are conductive belts provided with teeth that mesh with the reduction gear 61 and the pulleys 65 and 69 inside the endless annular belt. As the endless belt according to the present invention, a flat belt, a V-belt, or the like may be adopted. However, in a configuration in which the scanning of the full rate carriage 101 is controlled by the rotation of the stepping motor 60 as in the image reading apparatus 100, the reduction gear 61 is used. It is preferable to employ a toothed conductive belt that does not slip with respect to the pulleys 65 and 69 because the accuracy of scanning control is increased. The first timing belt 62 and the second timing belt 63 have mutually different tooth pitches. This makes it difficult for the vibration generated in the stepping motor 60 to be transmitted to the drive pulley 45 via the first timing belt 62 and the second timing belt 63. Therefore, although not shown in detail in the drawing, the pitch of the teeth of the pulleys 65 and 69 corresponds to the pitch of the teeth of the first timing belt 62 or the second timing belt 63, respectively. In 61, the tooth pitch of the large-diameter pulley 610 and the small-diameter pulley 611 also corresponds to the tooth pitch of the first timing belt 62 or the second timing belt 63, respectively.
[0028]
Hereinafter, a method of adjusting the tension of the first timing belt 62 and the second timing belt 63 in the main drive unit 106 will be described.
First, as shown in FIGS. 4 and 5, an engaging projection 643 formed on a base or the like of the image reading apparatus 100 and an elongated hole 643 formed on the base 640 of the first bracket 64 are engaged. Then, the first bracket 64 is positioned, and the screw 83 is inserted through the remaining long hole 643 and loosely screwed into the screw hole 80. In this state, the first bracket 64 is not tightened to the base or the like, and stands upright on the base or the like in support of the stepping motor 60, and in the tension direction of the second timing belt 63 within the range of the elongated hole 643. It can slide.
[0029]
Next, the hook-shaped ends of the springs 67 are hooked on the spring hook holes 645 formed in the motor support portion 641 of the first bracket and the spring hook portions 82 of the apparatus main body, respectively. The spring 67 is stretched between the spring 645 and the spring retaining portion 82. As a result, a tensile force is applied to the first bracket 64 in a direction in which the second timing belt 63 is tensioned, and the first bracket 64 moves toward the spring hooking portion 82 within the range of the elongated hole 643.
[0030]
On the other hand, as shown in FIGS. 5 and 6, the engagement protrusion 648 formed on the bracket fixing portion 642 of the first bracket 64 and the elongated hole 660 formed on the second bracket 66 are engaged with each other. The second bracket 66 is positioned, and the screw 83 is inserted through the remaining long hole 660 and loosely screwed into the screw hole 646 of the bracket fixing portion 642. In this state, similarly to the first bracket 64, the second bracket 64 is not tightened to the bracket fixing portion 642, is supported by the bracket fixing portion 642 while supporting the reduction gear 61, and has a long hole 660. Is slidable in the tension direction of the first timing belt 62.
[0031]
Next, the hook-shaped ends of the springs 68 are hooked on the spring hooks 648 formed on the bracket fixing portion 642 of the first bracket and the spring hooks 661 of the second bracket, respectively. The spring 68 is stretched between the portion 648 and the spring retaining portion 661. As a result, a pulling force acts on the second bracket 66 in the direction in which the first timing belt 62 is tensioned, and moves to the distal end side of the bracket fixing portion 642 within the range of the elongated hole 660.
[0032]
The second bracket 66 is moved toward the stepping motor 60 within a range of the elongated hole 660 against the pulling force of the spring 68, and in that state, a pulley 65 provided on a drive shaft 60a of the stepping motor 60 and a reduction gear The first timing belt 62 is wound between the large-diameter pulleys 61a. Thereafter, when the second bracket 66, which has been moved toward the stepping motor 60, is released, the second bracket 66 moves to the tip end side of the bracket fixing portion 642 of the first bracket 64 by the tensile force of the spring 68 and the first timing. A tension is applied to the belt 62, and the second bracket 66 stops at a position where the tension and the tension are balanced.
[0033]
On the other hand, the first bracket 64 is moved toward the spring engaging portion 82 within the range of the elongated hole 643 against the pulling force of the spring 67, and in this state, the small-diameter pulley 61 b of the reduction gear 61 and the driving pulley 45 The second timing belt 63 is wound around a pulley 69 provided on the drive shaft 45a. Thereafter, when the first bracket 64 that has been moved to the spring hooking portion 82 side is released, the first bracket 64 moves to the spring hooking portion 82 side by the tensile force of the spring 67, and the second timing belt 63 becomes tightly tensioned. Is provided, and the first bracket 64 stops at a position where the tensile force and the tension are balanced. At this time, the second bracket 66 is slidably movable in a state where a tension force is applied by a spring 68, and by applying a tension force by a spring 67 to the second timing belt 63, the first timing belt 62 is A position where the tension and the tension of the first timing belt 62 and the second timing belt 63 are balanced by the relative tension of the two springs 67 and 68 respectively acting on the second timing belt 63 and the second timing belt 63. Thus, the first bracket 64 and the second bracket 66 are stationary. That is, the tension between the first timing belt 62 and the second timing belt 63 and the spring between the spring hook 82 provided on the apparatus main body and the pulley 69 provided on the drive shaft 45 a of the drive pulley 45. The tensile forces of 67 and 68 are in equilibrium.
[0034]
At this equilibrium position, the screws 83 are tightened to tighten the main body of the apparatus and the base 640 of the first bracket 64 and to tighten the bracket fixing portion 642 of the first bracket 64 and the second bracket 66, so that the second bracket 66 is tightened. The first timing belt 62 and the second timing belt 63 can be stretched with a constant tension. If the first timing belt 62 and the second timing belt 63 become loose with time, the screws 83 are loosened once, and the tightening between the apparatus body and the base 640 of the first bracket 64 is performed. By releasing the tightening between the bracket fixing portion 642 of the bracket 64 and the second bracket 66, the tensile force of the springs 67 and 68 is applied again to apply a tension to the first timing belt 62 and the second timing belt 63. Can be. Note that the present tension adjusting method is an example, and the order of the temporary fixing of the first bracket 64 and the second bracket 66, the hooking of the springs 67 and 68, the winding of the first timing belt 62 and the second timing belt 63, and the like are described below. Of course, it can be changed as appropriate.
[0035]
Further, according to the present drive unit 106, the tension of the timing belt can be easily adjusted with a simple configuration. Therefore, as shown in FIG. 2, within the scanning range of the full rate carriage 101, that is, inside the guide rail 103. The first bracket 64 can be fixed at a position where the reflected light from the document does not interfere with the optical path guided to the imaging unit 105, and the stepping motor 60, the reduction gear 61, and the like can be arranged. As in the past, when adjusting the tension of the timing belt at the time of installation or maintenance, a high level of skill is required of the operator, or a large type with a roller that presses the timing belt, etc. In consideration of interference with the optical path and the like, the driving source, the reduction gear, and the like are provided outside the scanning range of the carriage, that is, outside the guide rail 103. Therefore, the size of the image reading apparatus has increased accordingly.
[0036]
However, since the present drive unit 106 does not include a large-volume member such as a roller that presses the timing belt unlike the related art, a position that does not interfere with the optical path of the reflected light from the document or the scanning of the full rate carriage 101 is used. And the tension of the first timing belt 62 and the second timing belt 63 can be easily adjusted by loosening and tightening the screws 83. It is not necessary to remove the carriage 101 and the like. Therefore, the drive unit 106 can be arranged within the scanning range of the full-rate carriage 101 without causing any inconvenience in the operation, thereby contributing to downsizing of the image reading apparatus 100.
[0037]
In this embodiment, the copy / facsimile multifunction peripheral 1 equipped with the image reading apparatus 100 has been described as an example, but the image reading apparatus according to the present invention can be applied to other apparatuses such as a scanner. It is. Also, the configuration of the image reading apparatus 100 shown in the present embodiment can be changed without changing the gist of the present invention. For example, in addition to the wire driving mechanism 104 as a carriage driving mechanism, a belt may be used. The driving mechanism used may be used. Instead of using two carriages, a full-rate carriage 101 and a half-rate carriage 102, to guide reflected light from a document to the imaging unit 105, a carriage having a CCD or the like is mounted. It is also possible to adopt a configuration in which an image is read by scanning a document.
[0038]
【The invention's effect】
Thus, according to the image reading apparatus of the present invention, the first bracket supporting the driving source is provided with the second bracket supporting the reduction gear so as to be slidable in the direction of tensioning the first endless belt, A spring is stretched between the first bracket and the second bracket, and the second bracket is fixed to the first bracket in a state where the spring is urged in a direction to tension the first endless belt. With this configuration, the tension of the first endless belt can be easily adjusted. Thereby, the work load at the time of installation of the apparatus and at the time of maintenance is reduced. In addition, it is also possible to reduce the size of the configuration for transmitting the drive from the drive source to the carriage drive mechanism, so that the drive source and the reduction gear can be arranged within the scanning range of the carriage, thereby reducing the size of the apparatus. Can contribute.
[0039]
Further, according to the present invention, the first bracket is provided on the apparatus main body so as to be slidable in a direction for tensioning the second endless belt, and a spring is stretched between the first bracket and the apparatus main body. As a result, the first bracket is fixed to the apparatus main body in a state where the second endless belt is urged in a direction to tension the second endless belt, so that the tension of the second endless belt can be easily adjusted with a simple configuration. Similar effects can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an external appearance of a multi-function facsimile machine 1;
FIG. 2 is a schematic perspective view showing the configuration of the image reading apparatus 100.
FIG. 3 is a front view illustrating a configuration of a full rate carriage 101, a half rate carriage 102, and a wire driving mechanism 104.
FIG. 4 is a perspective view showing an external configuration of the drive unit 106.
FIG. 5 is an exploded perspective view showing a detailed configuration of the drive unit 106.
FIG. 6 is an enlarged rear view showing a detailed configuration of the drive unit 106.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 Image reading device 101 Full rate carriage 102 Half rate carriage 103 Guide rail 104 Wire drive mechanism (carriage drive mechanism)
105 imaging unit 106 drive unit 45a drive shaft 60 stepping motor (drive source)
60a Drive shaft 61 Reduction gear 62 First timing belt (first endless belt)
63 2nd timing belt (2nd endless belt)
64 First bracket 66 Second bracket 67, 68 Spring

Claims (2)

A first endless belt is wound between the drive shaft of the drive source and the reduction gear, and a second endless belt is wound between the reduction gear and the drive shaft of the carriage drive mechanism. In an image reading apparatus in which a driving force is transmitted to a carriage driving mechanism via a reduction gear and the carriage scans a document,
A second bracket supporting a reduction gear is provided on the first bracket supporting the driving source so as to be slidable in a direction to tension the first endless belt,
A spring is stretched between the first bracket and the second bracket,
An image reading apparatus, wherein the second bracket is fixed to the first bracket in a state where the first endless belt is biased by the spring in a direction to tension the belt. The first bracket is provided on the apparatus main body so as to be slidable in a direction to tension the second endless belt,
A spring is stretched between the first bracket and the device body,
2. The image reading apparatus according to claim 1, wherein the first bracket is fixed to the apparatus main body in a state where the second endless belt is urged in a direction to tension the second endless belt by the spring.

Images