JP4288820B2 - Driving belt tension adjustment mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive device for a scanner device disposed in a scanning unit of an image reading device, and more particularly to a device that can easily adjust the tension of a belt for driving the scanner device.
[0002]
[Prior art]
In an image reading apparatus provided in combination with an image forming apparatus such as a facsimile machine or a copying machine, a scanner device that moves along the lower surface of a platen on which an original is set is disposed, and the scanner device is provided so as to be movable in the sub-scanning direction. ing. The scanner device may be configured as one unit by combining a lamp as a light source, a plurality of mirrors, an imaging lens, and a photoelectric conversion means such as a CCD. Then, by moving the scanner device along the original, information obtained by reading the original image is output as a digital signal. In addition to being used as a transmission signal for a facsimile machine, the digital signal transmitted from the scanner device is transmitted to a writing means in an image recording unit in a copying machine, and used to write optical information on a photoconductor. ing.
[0003]
[Problems to be solved by the invention]
When a single driving device is used to move the scanner device arranged in the scanning device, the scanner device is connected to a driving belt driven by the driving device and reciprocates along the lower surface of the platen. The image of the original is read on the forward path of the movement of the scanner device. Therefore, in a state where a constant tension is not applied to the driving belt, the moving speed of the scanner device becomes unstable and the reading speed is not constant. In addition, when the drive belt is stretched or the like, it is necessary to adjust the stretch of the drive belt as needed. Conventionally, a tension adjusting device is disposed at the end opposite to the drive side, The tension is kept constant. However, when the tension adjusting device is arranged inside the main body frame of the image reading device, for example, it is necessary to adjust the tension of the drive belt with the platen removed, and maintenance for the tension adjusting device is troublesome. The problem remains.
[0004]
The present invention is intended to solve the problems of the conventional tension adjusting device as described above, and provides a tension adjusting mechanism for a driving belt that can automatically adjust the belt tension and can be easily maintained. It is an object.
[0005]
[Means for Solving the Problems]
The present invention relates to a tension adjustment mechanism for a drive belt. The invention of claim 1 of the present invention relates to a guide rib member provided on a bottom frame of an image reading apparatus, an attachment portion for attaching to the bottom frame, and a belt. A bracket comprising a support portion for supporting the driven pulley, and an elastic member for urging the bracket and applying tension to the belt, and the guide rib member is provided in the mounting portion so that the belt can be stretched. A long hole that can be inserted is provided , a plurality of convex portions are provided in the long hole, and a guide rib member abuts on the convex portion . With the above configuration, even when the driving belt is slack, the tension can be automatically adjusted, and the slack of the driving belt can be easily eliminated.
[0006]
A second aspect of the present invention, before Kitotsu portion provided on an inner wall that faces the long holes, the spacing of the convex portions the opposite is characterized in that it is substantially the same form as the thickness of the guide rib members. Therefore, the pulley in the tension adjusting device can be moved along the direction in which the tension of the drive belt is applied, and the scanner device can be moved stably.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The holding structure of the scanner of the present invention will be described according to the illustrated example. FIG. 1 is a plan view of the image reading apparatus of the present invention, and FIG. 2 is a front view thereof. As shown in FIGS. 1 and 2, the lower side of the platen 2 of the image reading apparatus 1 is shown. The scanner device 10 that moves and reads the image of the document is guided by a guide rail 7 disposed on the front side of the device frame 3 and a guide rod 8 disposed on the rear side. The scanner device 10 is provided with projecting slide members 17 and rod sliding members 18 at both ends in a direction perpendicular to the moving direction, and a belt fixing portion 19 provided on the rod sliding member 18 side of the device for driving. It is connected to the belt 25 and reciprocated by the driving device 20. In order to move the scanner device 10, the rod sliding member 18 is guided to the guide rod 8 without play on the rear side of the device, and a sliding surface having a small friction coefficient is provided on the front frame 4 side. The slide member 17 is slid on the guide rail 7.
[0008]
The scanner device 10 is configured as a single reading unit. In addition to the lamp 11 and the mirror 12, the scanner device 10 is provided with a plurality of mirrors that reflect light. Then, the light reflected by the mirror at the end is imaged on the CCD 14 via the lens 13, and the optical signal is output as a digital signal by the CCD 14. As shown in FIG. 2, the frame 3 of the image reading apparatus 1 is provided by combining a front frame 4, a rear frame 5, and a bottom frame 6 with respect to a platen 2 disposed at an upper portion, and an inner surface of the front frame 4. The guide rail 7 is disposed so as to protrude, and the guide rod 8 and the driving belt 25 are disposed in parallel inside the rear frame 5. In the scanner device 10, the driving side of the driving belt 25 is attached to the belt fixing portion 19, and the belt return side 25 a is arranged along the bottom frame 6 of the frame.
[0009]
The driving device 20 for reciprocating the scanner device 10 drives a driving pulley 23 from a motor 21 supported on the rear frame 5 via a belt 22 and uses a driving belt 25 wound around the driving pulley 23 to scan the scanner device 10. The apparatus 10 is driven. A tension adjusting device 30 is provided on the other side of the driving device 20. In the tension adjusting device 30, a pulley 34 is supported by an L-shaped bracket whose position can be adjusted, and a tension spring 40 is used to determine a predetermined position. Is applied to the driving belt 25 so that a constant value of tension is applied to the driving belt 25. Then, in accordance with the information on the size of the document set on the platen, the motor 21 is rotated in the forward direction to move the scanner device 10 in the sub-scanning direction. When performing the operation of returning to the original position, the tension of the driving belt 25 is prevented from fluctuating, and the moving speed of the scanner device 10 when reading the original can be maintained at a constant speed.
[0010]
The tension adjusting device 30 disposed to face the driving device is configured as shown in FIGS. 3 to 5, FIG. 3 is a plan view, FIG. 4 is a side view, and FIG. 5 is a driving side. The front view seen from is shown. As shown in the drawings, the L-shaped bracket that supports the pulley 34 by the tension adjusting device 30 is constituted by a bracket vertical plate 31 and a bracket horizontal plate 32, and the bracket vertical plate 31 is interposed via a support shaft 33. The pulley 34 is rotatably provided, and is provided with a biasing means for a tension adjusting device that can apply a constant tension to the drive belt 25. In order to cause the tension adjusting device 30 to guide and hold the bottom frame 6 of the image reading device, the bottom frame 6 is provided with a guide rib member 28 and screwing boss members 29 and 29a described later. A long hole member 35 corresponding to the guide rib member 28 and screw holes 43 and 44 as long holes for the boss member are provided in the bracket lateral plate 32 of the tension adjusting device.
[0011]
As shown in FIG. 3, a long hole member 35 corresponding to the guide rib member 28 is provided in the bracket horizontal plate 32 of the tension adjusting device, and on both sides of the inner surface of the hole of the long hole member 35. Corresponding to the guide rib member 28, convex members 36, 36a and 37 are provided so as to protrude at a predetermined arrangement interval. At the end of the bracket horizontal plate 32 on the driving device side, a locking projection 41 is provided by projecting, for example, and protruding from the bottom frame 6, and a main body pin 42 and a locking projection 41 are provided. A tension spring 40 is disposed between the brackets of the tension adjusting device 30 and biases the bracket in the direction in which the bracket is separated from the driving device. As shown in FIGS. 4 and 5, screw holes 43 formed as long holes on both sides of the long hole member 35 with respect to the guide rib member 28 provided so as to protrude from the bottom frame 6 in the bracket horizontal plate 32, 44 is provided. By inserting the boss members 29 and 29a protruding upward from the frame bottom plate 6 into the screw holes 43 and 44, the tension of the driving belt 25 acts on the bracket horizontal plate 32 by three guide members. It is provided to be movable in the direction of Then, by attaching the set screws 45, 46 to the boss members 29, 29a, the tension adjusting device 30 is attached to the bottom frame 6, so that the set screws 45, 46 can prevent the bracket horizontal plate 32 from being lifted. To do.
[0012]
When the tension adjusting device 30 having the configuration shown in FIGS. 3 to 5 is provided, when the driving belt 25 wound around the pulley 34 is slack, the tension spring 40 causes the driving belt 25 to be slack. The slack is eliminated and the predetermined tension is maintained. When the movement of the tension adjusting device 30 for making the tension constant is performed, the convex members 36 are provided on both sides of the guide rib member 28 positioned on the long hole member 35 of the bracket horizontal plate 32. , 36a and the convex member 37 provide an operation of guiding in a state without play in a direction orthogonal to the direction in which the tension of the drive belt acts. Further, the bracket horizontal plate 32 slides on the boss members 29 and 29a provided on the bottom frame with respect to the screw holes 43 and 44 formed as long holes arranged at two different intervals. The tension adjusting device 30 is guided so as to be provided. Then, the set screws 45 and 46 attached to the boss member guide the movement while preventing the bracket horizontal plate 32 from being lifted, so that the pulley 34 supported by the tension adjusting device 30 faces the tension of the drive belt. It is possible to move only in the direction to do.
[0013]
When the tension adjusting device 30 is attached to and detached from the bottom frame 6, the platen (shown in FIG. 2) 2 provided on the upper part of the main body frame is removed, but the bracket of the tension adjusting device 30 is attached. When attaching and detaching, it is possible to take out from the bottom frame 6 only by attaching and detaching the two set screws 45 and 46. Further, during the maintenance of the apparatus, the operation of attaching / detaching the drive belt 25 to / from the pulley 34 and the operation of attaching / detaching the tension spring 40 can be easily performed from the upper part of the frame with the platen removed. Further, in maintenance that cannot be dealt with by adjusting only the tension spring 40, the tension adjusting device can be positioned by loosening the set screws 45 and 46, and then tightened again to fix the set screw. is there.
[0014]
It should be noted that in each component member arranged in the tension adjusting device, the number and the arrangement interval of the convex members provided to protrude from the inner surface of the long hole member 35 of the bracket horizontal plate 32 with respect to the guide rib member 28 provided in the bottom frame 6. Etc. can be arbitrarily set according to the tension value required for the drive belt 25, the driving force in the driving device, and the like. Further, since the screw holes 43 and 44 are used together with the guide rib member 28 as a guide for movement of the tension adjusting device 30, the screw holes 43 and 44 with respect to the bosses 29 and 29a to which the set screws 45 and 46 are attached. Therefore, the screw holes 43 and 44 sliding with the boss members 29 and 29a can be allowed to move in the direction in which the tension of the drive belt 25 is applied, and in the lateral direction. It should be formed in a state where there is no room.
[0015]
【The invention's effect】
Since the present invention is configured as described above, the guide rib member provided on the bottom frame of the image reading apparatus, the bracket including the support portion for supporting the pulley, and the bracket stretches the belt by the elastic member. Thus, even if the drive belt sags, the tension can be automatically adjusted, and the sag of the drive belt can be easily eliminated. In addition, the elongated hole member is provided with a plurality of convex portions, the guide rib member abuts on the convex portions, and the interval between the opposing convex portions is formed to be substantially the same as the thickness of the guide rib member. The pulley in the tension adjusting device can be moved along the direction in which the tension of the drive belt is applied, and the scanner device can be moved stably.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of an image reading apparatus of the present invention.
2 is a plan view of the image reading apparatus in FIG. 1. FIG.
FIG. 3 is a plan view of a tension adjusting device.
FIG. 4 is a side view of the tension adjusting device.
FIG. 5 is a front view of a tension adjusting device.
[Explanation of symbols]
1 image reader, 2 platen, 3 frame,
4 Front frame, 5 Rear frame, 6 Bottom frame,
7 guide rail, 8 guide rod, 10 scanner device,
11 lamp, 12 mirror, 13 lens, 14 CCD,
17 Slide member, 18 Rod slide member,
19 belt fixing part, 20 driving device, 21 motor,
22 conductive belt, 23 driving pulley, 25 driving belt,
28 guide rib members, 29 boss members, 30 tension adjusting devices,
31 Bracket vertical plate, 32 Bracket horizontal plate, 33 Support shaft,
34 pulley, 35 long hole member, 36/37 convex member,
40 tension spring, 41 locking projection, 42 body pin,
43/44 screw hole, 45/46 set screw.

Claims (2)

A guide rib member provided on the bottom frame of the image reading device;
A bracket comprising an attachment portion for attachment to the bottom frame and a support portion for supporting a driven pulley of the belt;
An elastic member for urging the bracket and applying tension to the belt;
The bracket is provided with a long hole into which the guide rib member can be inserted so that a belt can be stretched ,
A drive belt tension adjusting mechanism, wherein the elongated hole is provided with a plurality of convex portions, and guide rib members abut against the convex portions . The convex portion is provided on an inner wall facing the long hole, the tension of the drive belt according to claim 1, intervals of the projections of the opposing characterized Rukoto is substantially the same form as the thickness of the guide rib member Adjustment mechanism.

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