JP2001235811A - Tension regulating mechanism of drive belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a tension regulating device for imparting specified tension to a drive belt for driving a scanner to be disposed at an image reader as a device which is sure in operation, facilitates maintenance and is simple in structure. SOLUTION: This tension regulating device 30 has a guide rib member 28 disposed at a bottom frame 6 of the image reader, a bracket which is formed of a cross plate 32 for attaching to this bottom frame 6 and a standing plate 31 for supplying a pulley 34 to an L shape, and an elastic member for energizing the bracket imparting tension to the drive belt 25. The guide rib member 28 is inserted into the cross plate 32 and a long hole member 35 for guiding the regulating device 30 in the spreading direction of the belt is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a scanner device disposed in a scanning section of an image reading device, and more particularly to a device for easily adjusting the tension of a belt for driving the scanner device.

[0002]

2. Description of the Related Art In an image reading apparatus provided in combination with an image forming apparatus such as a facsimile apparatus or a copying machine, a scanner apparatus which moves along the lower surface of a platen on which an original is set is arranged, and the scanner apparatus is moved in the sub-scanning direction. It is provided movably. 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 unit such as a CCD. Then, by moving the scanner device along the document, information obtained by reading the image of the document is output as a digital signal. The digital signal transmitted from the scanner device is used as a transmission signal of a facsimile device, and in a copying machine, is transmitted to a writing unit in an image recording unit and used to write optical information on a photoconductor. ing.

[0003]

When one drive device is used to move the scanner device arranged in the scanning device, the scanner device is connected to a drive belt driven by the drive device, The scanner is reciprocated along the lower surface of the platen, and reads the image of the document on the outward path of the movement of the scanner device. Therefore, in a state where a constant value of tension is not applied to the drive belt, the moving speed of the scanner device becomes unstable, and there is a problem that the reading speed is not constant. Further, when the drive belt is stretched or the like, it is necessary to adjust the stretch of the drive belt at any time. Conventionally, a tension adjusting device is disposed at the end opposite to the drive side, and the The tension is kept constant. However,
When the tension adjusting device is disposed 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. And other problems remain.

An object of the present invention is to solve the above-mentioned problems of the conventional tension adjusting device, and to provide a drive belt tension adjusting mechanism capable of automatically adjusting the belt tension and performing maintenance easily. It is intended to provide.

[0005]

The present invention relates to a mechanism for adjusting the tension of a driving belt, and a first aspect of the present invention relates to a guide rib member provided on a bottom frame of an image reading apparatus, and the bottom frame. A bracket including a mounting portion for mounting the belt on a belt and a supporting portion for supporting a driven pulley of the belt; and an elastic member for urging the bracket to apply tension to the belt, and the belt can be stretched on the bracket. The mounting portion is provided with a long hole into which the guide rib member can be inserted. Further, according to the above configuration, even when the drive belt is slackened, the tension can be automatically adjusted, and the slack of the drive belt can be easily eliminated.

According to a second aspect of the present invention, a plurality of projections are provided in the elongated hole, and a guide rib member abuts on the projections. The invention according to claim 3 is characterized in that the projections are provided on inner walls of the elongated holes facing each other, and the interval between the facing projections is formed substantially equal to the thickness of the guide rib member. Therefore, the movement of the pulley in the tension adjusting device can be performed along the direction in which the tension of the drive belt is applied, and the movement of the scanner device is performed in a stable state.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A holding structure of a scanner according to the present invention will be described with reference 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. The scanner device 10 that moves and reads an image of a document is guided by a guide rail 7 disposed on the front side of the apparatus frame 3 and a guide rod 8 disposed on the rear side. The scanner device 10 has a slide member 17 and a rod slide member 18 protrudingly provided at both ends in a direction perpendicular to the moving direction, and a belt fixing portion 19 provided on the rod slide member 18 side of the scanner for driving. It is connected to the belt 25 and reciprocated by the drive device 20. In order to move the scanner device 10, the rod sliding member 18 is guided without play on the guide rod 8 on the rear side of the device, and a sliding surface having a small coefficient of friction is provided on the front frame 4 side. The slide member 17 slides on the guide rail 7.

The scanner device 10 is configured as one reading unit, and is provided with a plurality of mirrors for reflecting light in addition to the lamp 11 and the mirror 12 on the main body of the device. Then, the light reflected by the mirror at the end is imaged on the CCD 14 via the lens 13, and the CCD 14 outputs an optical signal as a digital signal. The frame 3 of the image reading device 1 is shown in FIG.
As shown in FIG. 3, the front frame 4, the rear frame 5 and the bottom
The guide rails 7 are arranged so as to protrude from the inner surface of the front frame 4, and the guide rods 8 and the driving belt 25 are arranged in parallel inside the rear frame 5. The scanner device 10 attaches the driving side of the driving belt 25 to the belt fixing portion 19,
The return side 25a of the belt is located along the bottom frame 6 of the frame.

A driving device 20 for reciprocating the scanner device 10 includes a motor 2 supported on the rear frame 5.
The drive pulley 23 is driven from 1 via the belt 22, and the scanner device 10 is driven using the drive belt 25 wound around the drive pulley 23. 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. 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 forward to move the scanner device 10 in the sub-scanning direction, and after reading is completed, the motor 21 is rotated reversely to place the scanner device 10 in the standby position. When the operation of returning to the original state is performed, the tension of the driving belt 25 is prevented from fluctuating, and the moving speed of the scanner device 10 at the time of reading a document can be maintained at a constant speed.

The tension adjusting device 30 arranged to face the driving device is configured as shown in FIGS. 3 to 5, and FIG. 3 is a plan view, FIG. Shows a front view as seen from the driving side. As shown in each of the drawings, the L-shaped bracket supporting the pulley 34 with the tension adjusting device 30 includes a bracket vertical plate 31 and a bracket horizontal plate 3.
The bracket vertical plate 31 has a support shaft 3
3, a pulley 34 is rotatably provided via the drive belt 2
5 is provided together with an urging means for a tension adjusting device which can apply a constant value of tension to the tension adjusting device. The tension adjusting device 3
In order to perform the guiding and holding action on the bottom frame 6 of the image reading apparatus, a guide rib member 28 and screwing boss members 29, 29 described later are provided on the bottom frame 6.
a and the guide rib member 2
8 and screw holes 43 and 44 as long holes for the boss member are provided in the bracket horizontal plate 32 of the tension adjusting device.

As shown in FIG. 3, an elongated hole member 35 corresponding to the guide rib member 28 is provided on the bracket horizontal plate 32 of the tension adjusting device, and an inner surface of the hole of the elongated hole member 35 is formed. On both sides, convex members 36, 36a and 37 are provided so as to correspond to the guide rib members 28 and protrude at predetermined intervals. At the end of the bracket lateral plate 32 on the drive device side, a main body pin 42 protrudingly provided on the bottom frame 6 is provided by cutting and erecting a locking projection 41 or the like.
A tension spring 40 is arranged between the locking projection 41 and the locking projection 41 to urge the bracket of the tension adjusting device 30 in a direction of separating the bracket from the driving device. Also,
As shown in FIGS. 4 and 5, guide rib members 2 provided on the bracket horizontal plate 32 so as to protrude from the bottom frame 6.
Screw holes 43 and 44 formed as long holes are provided on both sides of the long hole member 35 for 8. The screw holes 43, 44
By inserting the boss members 29 and 29a projecting upward from the frame bottom plate 6, the bracket lateral plate 32 can be moved in a direction in which the tension of the driving belt 25 acts by three guide members. Provide. 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 rising. I do.

By providing the tension adjusting device 30 having the structure as shown in FIGS. 3 to 5, when the drive belt 25 wound around the pulley 34 becomes slack,
The tension spring 40 eliminates the slack of the drive belt 25 to maintain a predetermined value of tension. When performing the operation of moving the tension adjusting device 30 to keep the tension constant, the guide rib members 28 positioned on the long hole members 35 of the bracket horizontal plate 32 are provided with convex members 36 on both sides thereof. , 36a and the convex member 37 provide an action of guiding in a direction perpendicular to the direction in which the tension of the drive belt acts without play. Also, with respect to the bracket horizontal plate 32, screw holes 43 and 44 formed as long holes arranged at different intervals are provided.
Boss members 29 and 29a provided on the bottom frame are slidably provided to guide the tension adjusting device 30. The set screws 45 and 46 mounted on the boss member guide the movement of the bracket 32 while preventing the bracket horizontal plate 32 from floating, so that the pulley 34 supported by the tension adjusting device 30 faces the tension of the drive belt. Movement is allowed only in the direction of

When attaching and detaching the tension adjusting device 30 to and from the bottom frame 6, the operation is performed with the platen (shown in FIG. 2) 2 provided on the upper portion of the main frame removed.
When attaching and detaching the bracket of the tension adjusting device 30,
Only by attaching and detaching the two setscrews 45 and 46, they can be taken out from the bottom frame 6. In maintenance of the apparatus, the operation of attaching and detaching the drive belt 25 to and from the pulley 34 and the operation of attaching and detaching the tension spring 40 can be easily performed from above the frame with the platen removed. Further, in the case of maintenance that cannot be dealt with by adjusting only the tension spring 40, the set screws 45 and 46 are loosened to position the tension adjusting device, and then the set screw is tightened again, so that it is possible to easily cope with the problem. is there.

In each of the components arranged in the tension adjusting device, a guide rib member 2 provided on the bottom frame 6 is provided.
8, the number and arrangement intervals of the protruding members provided on the inner surface of the long hole member 35 of the bracket horizontal plate 32 are determined by the value of the tension required for the driving belt 25, the driving force of the driving device, and the like. Can be arbitrarily set in accordance with. Further, the screw holes 43 and 44 are used as guides for the movement of the tension adjusting device 30,
Since it is used together with the guide rib member 28, the set screw 4
The screw holes 43 and 44 sliding with the boss members 29 and 29a are provided so that the screw holes 43 and 44 can be easily slid with respect to the bosses 29 and 29a on which the boss members 5 and 46 are mounted.
It is preferable that the drive belt 25 be formed so that it can be moved in the direction in which the tension is applied and there is no room in the lateral direction.

[0015]

Since the present invention is constructed as described above, the bracket formed by the guide rib member provided on the bottom frame of the image reading apparatus, the support portion supporting the pulley, and the bracket formed by the elastic member. Since the belt can be stretched, the tension can be automatically adjusted even when the drive belt is slackened, and the slack of the drive belt can be easily eliminated. Also, a plurality of convex portions are provided on the long hole member, and the guide rib member abuts on the convex portion, and the interval between the opposing convex portions is formed substantially equal to the thickness of the guide rib member. The pulley can be moved in the tension adjusting device along the direction in which the tension of the drive belt is applied, and the movement of the scanner device can be performed in a stable state.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of an image reading apparatus of the present invention.

FIG. 2 is a plan view of the image reading apparatus of FIG.

FIG. 3 is a plan view of the tension adjusting device.

FIG. 4 is a side view of the tension adjusting device.

FIG. 5 is a front view of the tension adjusting device.

[Explanation of symbols]

Reference Signs List 1 image reading device, 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 mirrors, 13 lenses, 1
4 CCD, 17 slide member, 18 rod slide member, 19 belt fixing portion, 20 drive device, 21 motor, 22 conduction belt, 23
Drive pulley, 25 drive belt, 28 guide rib member, 29 boss member, 30 tension adjusting device, 31 bracket vertical plate, 32 bracket horizontal plate, 33 support shaft, 34 pulley, 35 slot member, 36, 37 convex member, 40 tension spring, 41 locking projection, 42 body pin,
43/44 screw holes, 45/46 setscrew.

Claims (3)

[Claims] 1. A bracket comprising a guide rib member provided on a bottom frame of an image reading device, a mounting portion for mounting on the bottom frame, and a support portion for supporting a driven pulley of a belt, and urging the bracket. A tension adjusting mechanism for a drive belt, comprising: an elastic member that applies tension to the belt; and an elongated hole in which the guide rib member can be inserted into an attachment portion so that the belt can be stretched on the bracket. 2. The drive belt tension adjusting mechanism according to claim 1, wherein a plurality of projections are provided in the elongated hole, and a guide rib member abuts on the projections. 3. The device according to claim 1, wherein the convex portions are provided on inner walls of the elongated holes facing each other, and a space between the facing convex portions is formed to be substantially equal to a thickness of the guide rib member. Or the tension adjusting mechanism of the drive belt according to 2.