JPH09222759A - Driving system unit device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assemblability and to reduce manufacturing cost by constituting a driving system unit if a print to be freely attachable/detachable to/from a main body case. SOLUTION: A synthetic resin frame in the driving system unit freely attachable to/detachable from the part near one side of the main frame of the main body case is formed so that a difference part 600c in level is provided between the large width surfaces of the base plate part 600a of a transmission upstream side part to which power is transmitted from a driving motor 32 and of the base plate part 600b of a transmission downstream side part and the direction of the free end of a gear shaft 601 protruded from the base plate part 600a is opposite to those of the free ends of gear shafts 604-608 protruded from the base plate part 600b. Supporting metallic plates 72 and 73 supporting the free ends of each gear shaft are engaged with catchs 74 and 75 elastically provided on the circumferential side plate part 600b of the frame so as to face the large width surfaces of the respective base plate parts 600a and 600b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a drive system unit device in an image forming apparatus such as a copying machine, a facsimile machine, or a laser printer.

[0002]

2. Description of the Related Art Conventionally, a laser printer, which is an example of this type of image forming apparatus, includes a sheet feeding unit for feeding sheets for image formation, a photosensitive drum, a developing device for supplying toner to the photosensitive drum, and a transfer unit. A process unit including a roller, a scanner unit for forming an electrostatic latent image on a photosensitive drum, a fixing unit for heating and fixing a toner image transferred onto a sheet, and a drive for driving rotating parts in these units. It is provided with a motor, a transmission gear, a control device, and a power supply unit. These units are mounted on a metal plate or synthetic resin main frame, and a gear train for power transmission to each unit is mounted on this main frame so as to surround the main frame, the gear train, and the four circumferences of the unit. The main body case of the image forming apparatus is configured by fixing the synthetic resin case cover formed on the main frame to the main frame with screws or the like.

[0003]

However, in the case where the main frame has a flat plate shape, the gear shaft for rotatably supporting the gear protrudes like a support beam at one end with respect to the main frame. In order to increase the mounting strength of each gear shaft, it is necessary to provide each gear shaft so as to project by press fitting, caulking, etc., and to mount a gear on each gear shaft.

For this reason, it is necessary to handle a large-sized main frame for mounting the gear shaft and mounting the gear and the drive motor, which causes a problem that the manufacturing work is troublesome and the assembling performance is deteriorated. There is also a problem that the manufacturing cost increases because the main frame becomes large.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a drive system unit device which is easily assembled.

[0006]

To achieve this object, a drive system unit device in an image forming apparatus according to a first aspect of the present invention comprises a frame made of synthetic resin and a gear shaft for a gear train of the drive system. Are integrally projected, the gears are arranged and mounted on the respective gear shafts, the drive motor is fixed to one side of the wide surface of the frame to form a drive system unit, and the drive system unit is combined in an image forming apparatus. It is detachably attached to a resin main frame.

According to a second aspect of the present invention, in the drive system unit device in the image forming apparatus according to the first aspect,
The synthetic resin frame in the drive system unit,
It is formed so as to have a step between the wide surface of the base plate portion of the transmission upstream side portion for receiving the power transmission from the drive motor and the wide surface of the base plate portion of the transmission downstream side portion, and projects from the base plate portion of the transmission upstream side portion. A supporting metal plate that is formed so that the free end direction of the gear shaft and the free end direction of the gear shaft protruding from the base plate portion of the transmission downstream side are opposite to each other, and supports the free end of each gear shaft, It is mounted on the peripheral portion of the frame so as to face the wide surface of each of the substrate portions.

According to a third aspect of the invention, in the drive system unit device in the image forming apparatus according to the second aspect,
The peripheries of the respective support metal plates are locked by locking claws provided on the peripheral side plate parts of the respective board parts. According to a fourth aspect of the present invention, in the drive system unit device of the image forming apparatus according to the second or third aspect, a drive motor is provided on the support metal plate facing the substrate portion of the transmission upstream side portion. It is fixed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the present invention is embodied in a laser beam type printer will be described with reference to the drawings. FIG. 1 is a perspective view of main components of a laser printer as an image forming apparatus, and FIG. 2 is a schematic side sectional view of the laser printer. As shown in FIG. 1, the main body case 1 of the printer includes a scanner unit 2 and a process unit 3 from above.
A main frame 1a made of synthetic resin for mounting the fixing unit 4 and the paper feeding unit 5, and the main frame 1
The main frame 1a is made of synthetic resin and covers the outer surface of the four sides of a (front and rear and left and right sides), and the main frame 1a and the main cover 1b are integrally formed by injection molding or the like. The drive system unit 6 including the drive motor and the gear train is inserted from below the main body case 1 into the recess 33 between the left inner surface of the main cover body 1b in FIG. 1 and the left side of the main frame 1a adjacent thereto. And fix it. Further, the synthetic resin top cover 7 for covering the upper surfaces of the main frame 1a and the main cover body 1b has a hole 7a for penetrating the operation panel portion 1c protruding upward to the right of the main frame 1a. A hole 7b for penetrating the base of the sheet feeding unit 5 is formed. The base of the paper discharge tray 8 is mounted on brackets 9 and 9 (only one of which is shown in FIG. 1) protruding from the left and right sides of the front end of the top cover 7 so as to be vertically rotatable. The paper discharge tray 8 can be folded and covered on the upper surface side of the top cover 7.

The leading end side of the sheets P set in the feeder case 5a of the sheet feeding unit 5 in the stacked state is directed toward the sheet feeding roller 11 by the supporting plate 10 with the biasing spring 10a in the feeder case 5a. Paper feed roller 1 that is pressed and rotated by the power transmitted from the drive system unit 6 to rotate.
1 and the separation pad 12 separate the sheets one by one. The separated paper P has a pair of upper and lower registration rollers 13, 1.
The sheet P is fed to the process unit 3 at 4, and the image is formed on the surface of the sheet P by the toner at the process unit 3.
Is a heating roller 15 and a pressing roller 16 of the fixing unit 4.
After the image is fixed by and, it is ejected to the paper ejection tray 8.

An upper support plate 2a of the scanner unit 2 is provided at a lower portion of the process unit 3 which is arranged substantially in the center of the main frame 1a having an open upper surface of the body case 1 in plan view. The scanner unit 2 is fixed to a stay portion integrally formed on the upper surface side of the bottom plate portion with screws or the like. In the scanner unit 2, a laser emitting portion and a polygon mirror are provided on the lower surface side of an upper support plate 2a made of synthetic resin. 18, a lens 19, a reflecting mirror 20 and the like are arranged, and the process unit 3 is passed through a glass plate 21 that covers a horizontally long scanner hole formed in the upper support plate 2a so as to extend along the axis of the photosensitive drum 17. The outer peripheral surface of the photoconductor drum 17 is irradiated with a laser beam for exposure.

As shown in FIG. 2, the process unit 3 includes the photosensitive drum 17, a transfer roller 22 in contact with the upper surface thereof, a charging device 23 of a scorotron type or the like arranged below the photosensitive drum 17, and a charger. A developing device arranged upstream of the photosensitive drum 17 in the paper direction, a developer (toner) supply unit, that is, a detachable toner cartridge 24 arranged upstream thereof, and a downstream of the photosensitive drum 17. The cleaning device 25 and the like. An electrostatic latent image is formed on the outer peripheral surface of the photoconductor drum 17 by scanning the charged layer formed by the charger 23 with a laser beam from the scanner unit 2. Developer (toner) in the toner cartridge 24
Is discharged by being stirred by a stirring member 28, and then carried on the outer peripheral surface of the developing roller 27 via the supply roller 26,
The thickness of the toner layer is regulated by the blade. The electrostatic latent image on the photoconductor drum 17 is visualized by the developer adhering from the developing roller 27, and is transferred onto the sheet P passing between the transfer roller 22 and the photoconductor drum 17. Then, the toner remaining on the photosensitive drum 17 is collected by the cleaning device 25.

The process unit 3 is made into a cartridge by being incorporated in a case 29 made of synthetic resin, and the cartridge-shaped process unit 3 is detachably mounted on the main frame 1a. Also,
A downward facing rib 7 is provided on the lower surface of the synthetic resin top cover 7.
1 is provided so that the rib 71 faces the upper surface of the conveyance path of the sheet P from the registration roller pair 13 and 14 in the sheet feeding unit 5 to the transfer roller 22 in the process unit 3 so that the chute of the sheet P is formed. I have to. Therefore, when a paper jam occurs, the jammed paper P can be easily removed simply by removing the top cover 7.

FIG. 3 shows a drive mechanism by means of a gear train for each unit, and a part of this drive mechanism is collectively arranged on the left side of the main body case 1 of the printer as a drive system unit 6 as described later. ing. That is, the rotational force of the pinion gear 32a of the drive motor 32, which is fixed to the drive system unit 6 and can rotate in the forward and reverse directions, is equal to the two-stage gear 60.
(60a, 60b) and two-stage gear 61 (61a, 61b)
Via the gear 62, two-stage gear 63 (63a, 63b)
To the gear 11a that drives the paper feed roller 11 in the paper feed unit 5. The gear 63
The rotational force of the resist roller 13 is transmitted through the transmission gear 80.
Is transmitted to the gear 13a.

The rotational force of the two-stage gear 60 (60a, 60b) is the same as that of the three-stage gear 64 (64a, 64b, 64c).
Two-stage gear 65 (65a, 65b), two-stage gear 66 (66
a, 66b) and is transmitted to the gear 17b of the photosensitive drum 17 via the two-stage gear 67 (67a, 67b). Further, the rotational force of the two-stage gear 67 (67a, 67b) is transmitted to the gear 15a of the heating unit 15 of the fixing unit 4 via the gear 68 and the two-stage gear 69 (69a, 69b).

On the other hand, the rotational force of the two-stage gear 65 (65a, 65b) is transmitted to the agitator 28 via the gears 81, 82, 83, while it is transmitted through the gears 81, 84, 85 to the supply roller 26 and the developing device. It is transmitted to the roller 27. The frame 600 made of synthetic resin of the drive system unit 6 includes the drive motor 32, the pinion gear 32a, and the two-stage gears 60, 6
1, 63, 65, 66, 67, 69 and three-stage gear 64,
Gears 62 and 68 are incorporated.

The integral structure of the main frame 1a and the main cover body 1b will be described in detail with reference to FIGS. FIG. 4 is a schematic plan view of the main body case 1, and the main cover body is arranged so as to be continuously provided outside the four circumferences of the main frame 1a having a substantially rectangular upper surface open box shape located in the central portion of the main body case 1 in plan view. 1b is formed, and the right side portion 1a-in plan view of the main frame 1a-
1 and the left side portion 1a-2 are formed with bearing grooves 31 and 31 into which the left and right shaft portions 17a of the photosensitive drum 17 of the process unit 3 are fitted from above, respectively. Further, an operation panel portion 1c is formed in the front half of the right side portion 1a-1, and a storage recess 33 into which the drive system unit 6 is fitted from below is formed in the left side portion 1a-2. Some of them have open hole portions 34, 35, 36, 37 that allow the two-stage gears 63, 65, 67, 69, which are transmission portions to each unit, to face upward (see FIGS. 6 and 7). A stay for fixing the frame 600 of the drive system unit 6 is integrally projected downward on the lower surface side (inner surface side) of the storage recess 33.

The lower surface side of the main frame 1a, which is continuous with the rear portion 1a-3 and the rear surface of the main cover body 1b, has a drive motor 3 in the drive system unit 6.
2 and the power supply unit 40 are accommodated (see FIG. 6).
Further, a storage portion 42 for storing the cooling fan 41 and a paper P are provided on the lower surface side of the main frame 1a, which is continuously provided by the front portion 1a-4 and the front surface of the main cover body 1b.
And a ventilation duct 43 extending in a direction orthogonal to the passing direction of the above. In this case, the upper surface plate portion 43a of the ventilation duct 43 is formed in a substantially V shape with a downward cross section, and the upper surface plate portion 43a is located between the process unit 3 and the fixing unit 4 arranged on the upper surface side of the main frame 1a. Thus, the radiant heat from the heating roller 15 in the fixing unit 4 is prevented from being transmitted to the process unit 3 side (see FIGS. 2, 4, and 6). As shown in FIGS. 2 and 6, a partition plate 44 made of metal is continuously provided between lower ends of the upper surface plate portion 43a having a downward V-shaped cross section, and a portion surrounded by these members is a ventilation duct. 43, cooling fan 41
Is configured to pass the cooling air from.

The bottom plate portion 1a-of the main frame 1a
5, while supporting the scanner unit 2, the bottom plate portion 1
Part of the lower surface side of a-5 (left side part 1a-2 side part)
And a bottom plate 45 made of metal that fits and closes the lower ends of the front and rear sides of the main cover body 1b to form a ventilation path 46 that communicates with the space in which the drive motor 32 and the power supply unit 40 are housed. An air introduction port 47 and an exhaust port 48 are provided on the front side and the rear side of the body 1b, respectively.

Next, the structure of the drive system unit 6 will be described in detail with reference to FIGS. FIG. 7 shows a state in which the drive system unit 6 is fitted in the housing portion 33, and the frame 600 made of synthetic resin in the drive system unit 6 has a side (power) on which the drive motor 32 is mounted as shown in FIG. The stepped portion 600 is provided between the wide surface of the board portion 600a in the upstream portion of the transmission and the wide surface of the board portion 600b in the downstream portion of the transmission.
c, and a plurality of gear shafts 601, 602, 603 (representative gear shaft 601 is shown in FIG. 9) in the base plate portion 600a at the transmission upstream side) have their free ends on the drive motor 3 side.
2 protruding in the mounting direction of the base plate 6 of the transmission downstream side portion
00b multiple gear shafts 604, 605, 606, 6
07 and 608 are integrally molded so that their free ends project in the opposite direction (toward the main cover body 1b).

Around the board portions 600a and 600b, peripheral side plate portions 600d are integrally projected so that the frame 600 is formed in a box shape. Then, after fitting the gears corresponding to the respective gear shafts, the respective gear shafts 6
Support metal plate 7 having holes into which free ends 01 to 608 fit
2, 73 are opposed to the wide surfaces of the substrate portions 600a and 600b, and are locked by a plurality of locking claws 74, 75 and the like that are elastically projected on the peripheral side plate portion 600d (FIG. 9, FIG. 9).
10 and 12).

The gears 62 and 68 are idle gears,
The board portions 600a and 600b are provided with long groove portions 76 and 76, and the supporting metal plates 72 and 73 are attached to the supporting metal plates 72 and 73 so that the shaft portions 62a (68a) can rotate integrally with the gears 61b and 67a by appropriate distances. Are provided with long groove portions 77, 77, respectively.
Further, the drive motor 32 is fixed to the supporting metal plate 72 for the transmission upstream side portion.

With this configuration, the main body case 1 is the one in which the main frame 1a and the main cover body 1b are integrated, so that there is no need to attach the main cover body 1b to the main frame 1a as in the conventional case. Each of the gears 60 to 608 that form a predetermined gear train on the gear shafts 601 to 608 integrally formed in advance on the frame 600 made of synthetic resin.
After mounting 69, the drive system unit 6 in which the free ends of the respective gear shafts are supported by the supporting metal plates 72 and 73 is mounted on the main frame 1a. Therefore, by assembling the drive system unit 6 in advance, As a result, the assembling property of the image forming apparatus is improved, and at the time of maintenance, the workability is improved because only the drive system unit 6 needs to be attached and detached.

Since the free ends of the gear shafts protruding from the substrate portions 600a and 600b are supported by the supporting metal plates 72 and 73, even if the gear shafts themselves are made of synthetic resin, the flexure of the gear shafts can be reduced and the drive The rigidity of the system unit 6 can be improved. Further, the supporting metal plates 72, 73 also serve as the lid of the box-shaped frame 600 having an open side,
It is also possible to prevent dust and the like from entering from the outside.

Further, since the supporting metal plates 72, 73 are locked by the elastic locking claws of the frame 600, the work of screwing is unnecessary, and the supporting metal plates 72, 73 can be formed into a simple plate shape. Therefore, the manufacturing cost can be reduced.

[0026]

As described above, in the drive system unit device of the image forming apparatus according to the first aspect of the present invention, the frame made of synthetic resin integrally has the gear shaft for the gear train of the drive system. Projecting, placing gears on each gear shaft, mounting
A drive motor is fixed to one side of the wide surface of the frame to form a drive system unit, and the drive system unit is detachably attached to a synthetic resin main frame in the image forming apparatus.

Since it is only necessary to assemble a small-sized drive system unit in advance and then mount this drive system unit on the main frame, there is an effect that the assembling property and maintenance property of the image forming apparatus are greatly improved. According to a second aspect of the present invention, in the drive system unit device of the image forming apparatus according to the first aspect, a synthetic resin frame of the drive system unit is provided with a transmission upstream for receiving power transmission from the drive motor. Since it is formed so as to have a step between the wide surface of the substrate portion of the side portion and the wide surface of the substrate portion of the transmission downstream portion, the rigidity of the frame becomes higher than when the substrate portion is formed in a simple plate shape. In addition, the free end direction of the gear shaft protruding from the base plate portion of the transmission upstream side portion and the free end direction of the gear shaft protruding from the base plate portion of the transmission downstream side portion are formed in opposite directions to each other. Since the supporting metal plate supporting the free end of the frame is attached to the peripheral portion of the frame so as to face the wide surface of each of the substrate portions, the supporting metal plate has the transmitting upstream side portion and the transmitting downstream side portion. Divided into two Can, it is possible to increase the rigidity of the driving system unit.

The invention described in claim 3 is the same as that of claim 2
In the drive system unit device in the image forming apparatus described in, since the periphery of each of the support metal plate is locked by the locking claws provided on the peripheral side plate portion of each substrate portion,
The work of mounting the supporting metal plate is extremely simple, the shape of the supporting metal plate itself can be simplified, and the manufacturing cost can be reduced.

Further, the invention according to claim 4 is the drive system unit device in the image forming apparatus according to claim 2 or 3, wherein the supporting metal plate is opposed to the substrate portion of the transmission upstream side portion. Since the drive motor is fixed, the mounting of the supporting metal plate and the mounting of the driving motor can be done at once, improving the assemblability and transferring the heat generated from the driving motor to the supporting metal plate. This has the effect that it can also serve as a heat sink.

[Brief description of drawings]

FIG. 1 is a perspective view of main components of a laser printer.

FIG. 2 is a schematic sectional view of a laser printer.

FIG. 3 is a diagram of a power transmission mechanism to each unit.

FIG. 4 is a plan view of a main body case.

FIG. 5 is a side view taken along a line VV in FIG. 4;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 4;

FIG. 8 is a diagram showing a gear train of a drive system unit.

9 is a cross-sectional view of the frame taken along the line IX-IX in FIG.

10 is an enlarged cross-sectional view taken along the line XX of FIG.

FIG. 11 is a partially enlarged side view of a drive system unit.

12 is a sectional view taken along line XII-XII of FIG.

[Explanation of symbols]

 P Paper 1 Main body case of laser printer 1a Main frame 1b Main cover body 2 Scanner unit 3 Process unit 4 Fixing unit 5 Paper feeding unit 6 Drive system unit 11 Paper feeding roller 17 Photosensitive drum 32 Drive motor 60-69, 80-85 Gear 600 Frame 600a, 600b Substrate 600c Step 600d Surrounding side plate 601-608 Gear shaft 72,73 Support metal plate 74,75 Locking claw

Claims (4)

[Claims] 1. A synthetic resin frame integrally provided with a gear shaft for a gear train of a drive system, and gears are arranged and mounted on each gear shaft, and a drive motor is mounted on one side of a wide surface of the frame. A drive system unit device in an image forming apparatus, wherein the drive system unit is fixed to form a drive system unit, and the drive system unit is detachably attached to a synthetic resin main frame of the image forming apparatus. 2. A step made up of a synthetic resin frame in the drive system unit between a wide surface of a base plate portion at a transmission upstream side portion and a wide surface of a base plate portion at a transmission downstream side portion for receiving power transmission from the drive motor. So that the free end direction of the gear shaft protruding from the base plate portion of the transmission upstream side portion and the free end direction of the gear shaft protruding from the base plate portion of the transmission downstream side portion are opposite to each other. The image forming apparatus according to claim 1, wherein a supporting metal plate that is formed and supports a free end of each gear shaft is attached to a peripheral portion of the frame so as to face the wide surface of each substrate portion. Drive unit device in. 3. The drive in the image forming apparatus according to claim 2, wherein the periphery of each of the supporting metal plates is locked by a locking claw provided on a peripheral side plate portion of each substrate portion. System unit device. 4. The drive system unit in the image forming apparatus according to claim 2, wherein a drive motor is fixed to the supporting metal plate facing the substrate portion of the transmission upstream side portion. apparatus.