JP2001209221A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the size of a device small, to reduce the cost and to obtain stable operation. SOLUTION: In the device, a rotating member K# is supported rotatably by a burring part 102a and/or a projection part 102b formed on sheet metal members 101 and 102 and height of the burring part and/or projection part is made to be approximately more than twice but less than 10 times the thickness of the plate. A multiple number of the burring parts and the projecting parts are formed and a multiple number of pieces of the rotating parts are supported by the sheet metal member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for gears, rollers, and other rotating parts, and more particularly to an image forming apparatus using the mounting structure, such as a printer or a facsimile, for forming an image on a sheet material. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art A typical example of a conventional image forming apparatus is disclosed in Japanese Patent Application Laid-Open No. 1-222270. As shown in FIG. 15, the gear mounting structure in the power transmission mechanism of this device is such that a support shaft 502 for supporting the gear 501 is implanted in a frame 503, or both ends of a support shaft 505 inserted through a bearing portion 504. Gear was attached to the vehicle.

[0003] On the other hand, as a structure for mounting parts using burring, a structure disclosed in Japanese Patent Application Laid-Open No. 64-34531 is known. This structure is shown in FIG.
As shown in FIG. 17, a burring portion 511 is formed on a metal plate 510, a rotating component or a sliding member 512 is attached to the burring portion 511, and a tip 513 of the burring portion 511 is bent and rotated as shown in FIG. 17 or FIG. This is a structure in which the parts or the sliding members 512 are prevented from coming off.

[0004]

The environment surrounding computers in recent years has been spurred by downsizing from the rise of small notebook computers.
Along with this, the personal use market has expanded,
There has been an increasing demand for smaller external terminals such as printers and facsimile machines, which are suitable for miniaturization of computers, and for the appearance of inexpensive products so that they can be arranged with plenty of room even on personal desks.

However, it is not always possible for the above-described conventional technology to meet such a demand.

[0006] In the gear mounting structure disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-222270, as shown in FIG.
3 or a structure in which gears are attached to both ends of the support shaft 505 inserted through the bearing portion 504, so that the number of parts is large and complicated. Therefore, it is difficult to reduce the size and cost of the apparatus.

On the other hand, according to the structure disclosed in JP-A-64-34531, the number of parts is small and the structure is relatively simple, so that it is relatively easy to reduce the size and cost of the apparatus. It is thought that there is.

However, in this structure, it is necessary to bend the burring portion tip 513, and if this bending is not performed with high accuracy, the interval w shown in FIG. There is a disadvantage that stable operation of the member 512 cannot always be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus using a rotary component mounting structure capable of solving the above-mentioned problems, reducing the size and cost of the apparatus, and achieving stable operation. Is to do.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a rotatable member rotatably supported by a burring portion and / or a projection portion formed on a sheet metal member; Burring and / or
Alternatively, there is provided a rotating part mounting structure in which the height of the projection portion in the axial direction is about 2 to 10 times the plate thickness.

According to the second aspect of the present invention, there is provided an image forming apparatus according to the first aspect.
In the image forming apparatus described above, a plurality of the burring units and / or the projection units are formed, and a plurality of rotating parts are supported on the sheet metal member.

According to the image forming apparatus of the first aspect, the rotating member is rotatably supported on the burring portion and / or the projection portion formed on the sheet metal member, and the height of the burring portion and / or the projection portion in the axial direction is increased. Since it has a mounting structure of a rotating part whose thickness is about twice or more and about ten times or less, the rotating part is rotatably supported by the burring part and / or the projection part.

Therefore, according to such a structure, the burring part and / or the projection part is formed on the sheet metal member, and the rotating part is rotatable by supporting the rotating part on the burring part and / or the projection part. Since the support shaft can be attached, it is not necessary to perform the installation work, the insertion work to the bearing portion, or the bending process of the tip of the burring portion as required in the above-described conventional technology.

Therefore, an apparatus using such a structure can be reduced in size and cost, and can operate stably.

Further, since the supporting portion of the rotating component has a structure in which burring or projection processing is performed directly on the sheet metal member, the strength of the supporting portion is improved and the size is large as compared with a structure in which the supporting shaft is implanted in the frame. It can withstand axial force (power).

[0015] Further, the rotating part includes a burring part and / or a rotating part.
Alternatively, since a radial support load is received by the projection unit, it is desirable to set the axial height of the burring unit and / or the projection unit to an appropriate amount in order to cope with the support load. On the other hand, since the burring portion and / or the projection portion during mass production also has a slight relative displacement, the burring portion and / or the projection portion are required to cancel the relative displacement and to stably support the gear. It is effective to set the axial height of the projection unit low. On the other hand, according to the present invention, the height of the burring portion and / or the projection portion in the axial direction is set to the plate thickness of 2 mm.
Since it is about twice or more and about ten times or less, it becomes possible for the rotating parts to cope with the radial supporting load of the burring part and / or the projection part, and at the same time, the relative parts to the burring part and / or the projection part in mass production It is possible to cancel a positional shift, and to stably support the gear. That is, it is possible to obtain an image forming apparatus having a structure for mounting a rotating component that is rich in mass productivity in balance with the supporting load.

In any case, according to such a structure,
By forming the burring portion and / or the projection portion on the sheet metal member and supporting the rotating component on the sheet metal member, the rotating component can be rotatably mounted. Therefore, the support shaft as required in the above-described prior art described above. This eliminates the necessity of the installation work, the insertion work into the bearing part, and the bending of the tip of the burring part.

Therefore, an apparatus using such a structure can be reduced in size and cost, can achieve stable operation, and can be mass-produced.

Further, since the supporting portion of the rotating component has a structure in which burring and / or projection processing is performed directly on the sheet metal member, the strength of the supporting portion is improved as compared with a structure in which the supporting shaft is implanted in the frame. , Can withstand large axial force (power).

Therefore, in such a structure, when the number of rotating parts is large, that is, as described in claim 2, a plurality of burring parts and / or projection parts are formed, and a plurality of rotating parts are formed on the sheet metal member. It is particularly effective when supported.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 13 show a preferred embodiment of the image forming apparatus according to the present invention. FIG. 1 is a sectional view of a main part on the left side showing the entire image forming apparatus. FIGS. FIG. 2 is a sectional view taken along the line II-II in FIG. 6, and FIG. 3 is a sectional view taken along the line III-III in FIG.
2 and 3, the left side from the alternate long and short dash line is omitted.

FIG. 4 is a sectional view of a main part of the left side of the image forming unit (a sectional view taken along line IV-IV in FIG. 2), and FIG. 5 is a partially cut left side view.

FIGS. 6 and 7 are cross-sectional views of essential parts on the right side of the image forming apparatus. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3, and FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.

FIGS. 8, 9 and 10 are exploded cross-sectional views showing the rotation drive transmitting portion of the image forming apparatus, and also show an example of the mounting structure of the rotary component according to the present invention. 8 is a first developed sectional view, FIG. 9 is a second developed sectional view, and FIG. 10 is a third developed sectional view, each showing a different rotation drive path.

FIG. 11 is a cross-sectional view of a main part on the right side of the image forming unit and the toner tank, and also shows a rotation driven system.

FIG. 12 is a cross-sectional view of a main part of the upper surface of the image forming unit, and the left side is omitted from the dashed line in the figure.

FIG. 13 is an explanatory diagram showing a rotation drive system of the image forming unit.

First, the image forming section of this embodiment will be described with reference to FIG. 1 and other figures.

The main part of the image forming apparatus of this embodiment is shown in FIG.
The image forming unit U1 is disposed substantially at the center as shown in FIG.
And a photosensitive drum 1, a charging roller 2, a cleaner unit 9
0, a developing unit 10, and a toner conveying unit 30.

Each part will be described in the order of the image forming process with reference to FIGS. 1, 4 and 5.

The charging roller 2 in this embodiment is formed of a semiconductive elastic material such as rubber, for example, and rotates following the photosensitive drum 1 which rotates in the direction of the arrow in the figure. When a bias of about DC (−) 2 kv or less is applied to the charging roller 2, the photosensitive drum 1 is charged to a charging potential of (−) 600 V to (−) 700 V. The charging roller 2 is supported so as to be pressed toward the photosensitive drum 1 by a pressing mechanism (not shown), and is in pressure contact with the photosensitive drum 1 with a total pressure of approximately 1 kg.

The photosensitive drum 1 is image-exposed by a light beam 49 emitted from the exposure unit U2 to form a latent image. The potential of this image exposure portion is (−) 50 V to (−) 1
It becomes 50V.

The developing section 10 has a storage section 11 for storing toner which can be charged to the same polarity as the above-mentioned charging potential, a supply roller 13 and a developing sleeve 12. The supply roller 13 is formed of a semiconductive elastic material such as foamed rubber, for example, and rotates in the direction of the arrow in the figure to rotate so that the toner in the storage unit 11 is coated on the surface. The toner is frictionally charged to the negative polarity by rubbing against the rotating developing sleeve 12 made of a semiconductive elastic material such as a rubber material, and the surface of the developing sleeve 12 is coated with the toner.

The toner coated on the surface of the developing sleeve 12 is formed of an elastic material such as a stainless steel plate, and is in contact with the outer periphery of the developing sleeve 12 at a total pressure of approximately 1 kg over substantially the entire axial direction. By rubbing the applied toner with a regulating blade 14 for regulating the toner to a coating layer having a predetermined thickness, the toner is regulated to a thinner toner layer of about 10 μm, and a more uniform (−) ) It is triboelectrically charged to the polarity.

The developing sleeve 12 has a DC (-) 20
A bias of about 0 V to (−) 400 V is applied, and the thinned toner layer is conveyed to the photosensitive drum 1, and the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 and the vicinity thereof Is subjected to reversal development on the image exposure portion of the photosensitive drum 1.

As shown in detail in FIG. 4, the toner in the storage section 11 is provided with a unit upper case 17, a unit lower case 18, a regulating blade 14, a pressing member 16 of the regulating blade 14, The space surrounded by the sleeve 12 and the supply roller 13 is stored in a narrow predetermined space formed of, for example, a foamed rubber material and partitioned by an elastic seal 15.

The toner image reversely developed on the image exposure portion of the photosensitive drum 1 is transferred by a transfer portion 80 described later in detail.
The transfer residual toner slides through a rake sheet 91 formed of a thin sheet material such as a mylar sheet material and is scraped off by a cleaning blade 92 pressed against the photosensitive drum 1. It is stored in a predetermined space 93 formed.

The cleaned photosensitive drum 1 can be transferred to the next image forming process again. If the potential remaining on the photosensitive drum 1 is removed by light irradiation or the like after cleaning, the surface potential of the photosensitive drum 1 can be reduced. Can be brought closer to the initial state.

Here, the handling of the toner will be described.

The conventional image forming apparatus has a configuration in which a cartridge in which a predetermined amount of toner corresponding to the operating life of the above-mentioned main components such as a photoreceptor is sealed in an integrally formed casing is mounted. For this reason, although the workability of the replacement maintenance has been enhanced, not only the entire apparatus has been increased, but also the image forming apparatus has been expensive.

On the other hand, in this embodiment, the configuration is completely different from the conventional concept.

First, the amount of toner in the storage unit 11 is reduced to a minimum necessary amount that does not hinder the above-described image forming process, and the space of the storage unit 11 is reduced. The toner that decreases with the above-described development is configured to be dropped and replenished in the space of the storage unit 11 from a toner transport unit 30 that transports the toner, which will be described in detail later.

On the other hand, the toner scraped off by the cleaning blade 92 is stored in a predetermined space 93 formed by the rake sheet 91 and the cleaning blade 92.
Move to zero.

Then, the toner transport section 30 is moved to the position shown in FIG.
As shown in FIG. 2, the photosensitive drum 1 is disposed substantially horizontally in a track shape with the photosensitive drum 1 being substantially at the center, and a toner conveying means including an endless coil spring 31 is provided, so that the toner is circulated and conveyed. ing. The toner conveying unit 30 and the coil spring 31 that circulates and conveys the toner are configured to be endless although the left side is omitted from the dashed line in FIG.

Next, the toner circulation function will be described.

The amount of toner (development toner) in the storage unit 11 consumed by the above-described development is scraped off by the cleaning blade 92 and the toner transport unit 3
In the present embodiment, the relationship between the transfer remaining toner amount (reproduced toner amount) after shifting to 0 is 10% to 30%. Therefore, even if the toner is circulated and conveyed as described above, the toner is consumed by the repetition of the development, and the toner in the storage unit 11 decreases.

Therefore, in this embodiment, in order to compensate for the reduced toner, a toner replenishing means which falls by its own weight is arranged in a transport path for circulating the toner, which will be described in detail later.
The reduced toner is supplied, the supplied toner is circulated and transported together with the above-mentioned regenerated toner, and both toners are dropped and supplied from the toner transport unit 30 to the storage unit 11.

Next, a stable structure of the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 against each other will be described.
This will be described with reference to FIGS. 2, 4, 5 and 12.

The supply roller 13 formed of a semiconductive elastic material such as foamed rubber and the developing sleeve 12 formed of a semiconductive elastic material such as rubber are used as metal cores, respectively. Support members 12a and 13a are provided at the ends of the elastic member, and the support members 12a and 13a are, as shown in FIG.
It is rotatably supported by. Although the supply roller 13 and the developing sleeve 12 are shown on the right side in the drawing, the opposite side has a similar supporting structure, and the supporting member 5
It is rotatably supported by.

The supply roller 13 and the developing sleeve 12 are supported at a fixed pitch which is smaller than the pitch at which the outer circumferences of the supply roller 13 and the developing sleeve 12 are in contact with each other. It is. The positional relationship between the supply roller 13 and the developing sleeve 12 is shown in detail in FIGS.

The supply roller 13 and the developing sleeve 12 are each driven to rotate in the direction of the arrow shown in the drawing to rub.
If the interval between the support pitches is extremely narrow, the rotational driving torque becomes large, or the toner rubbed between the two roller nips becomes severely deteriorated. In this embodiment,
The supply roller 13 and the developing sleeve 12 are supported at a fixed pitch that is 0.25 mm narrower than the contact pitch.

The supporting members 5 and 5 (only one is shown) rotatably supporting both ends of the supply roller 13 and the developing sleeve 12 are firmly connected by a fixing means such as a screw via a connecting member 6 to be integrally formed. It has a configuration. FIG.
As shown in the figure, the support member 5 is rotatably supported by a support pin 7 inserted into a part of the unit lower case 18. FIG. 12 shows a state where only one side is supported, but the opposite side has a similar support structure.

The support member 5 is rotatably supported at both ends of the supply roller 13 and the developing sleeve 12 and connected to each other by the connecting member 6. Thus, the photosensitive drum 1 can be rotated integrally with the photosensitive drum 1 in the space of the toner storage unit 11 configured so as to have a minimum necessary storage amount that does not hinder the above-described image forming process.

When the support pin 7 is arranged at the position shown in FIGS. 4 and 5, the unit lower case 18 and the support member 5 are connected to each other so that the support pin 7 can be easily rotated under the above-mentioned integrated structure. The relationship is such that a gap is formed so as to be free in the rotation direction, and this gap is shielded by an elastic seal member (not shown) to prevent toner leakage.

On the other hand, in order to form a stable nip by pressing the developing sleeve 12 and the photosensitive drum 1 in the above state, the hooks at both ends are set in the unit lower case 18 and the tension is applied to the supporting member 5. Applying and developing sleeve 12
Springs 8 (only one is shown) for urging the photosensitive drum 1 toward the photosensitive drum 1 are also provided.

Regarding the support structure of the support member 5 by the support pin 7 described above, in this embodiment, as a means for preventing a rotation problem even if a difference occurs between the left and right support positions, one of the support portions has a unit lower case 18. The insertion portion through which the support pin 7 of the support member 5 is inserted is formed in the same circular shape as the support pin 7, and the other support portion through which the unit lower case 18 and the support pin 7 of the support member 5 are inserted is In addition, the support pin 7 forms an oblong opening 18b which can freely move toward and away from the photosensitive drum 1, thereby preventing the above-described configuration from causing rotation failure.

Although the oblong opening 18b is formed in the unit lower case 18 in the present embodiment, the unit lower case 18 is reversed and the opening on the support member 5 side is made oval. Even if both openings are formed, or both openings are formed in an oval shape, the occurrence of the rotation failure of the above configuration is prevented.

Here, the toner replenishing means and the toner conveying means for circulating and conveying the toner will be described with reference to FIGS. 2 and 3 and FIGS. 11 and 12.

As shown in FIGS. 4 and 5, the endless coil spring 31 for circulating and conveying the toner is sealed in the unit upper case 17 and the unit lower case 18, and the toner tank 20 (see FIGS. 3 and 11). ) Is configured to be attachable / detachable (the attach / detach mechanism is omitted from the illustration and description). The toner tank 20 has a configuration in which a predetermined amount of toner is sealed therein, and is mounted in the unit U1 in a toner sealed state to supply toner, and when the toner is consumed, the toner tank 20 is replaced with a new toner tank 20. Has become.

As shown in FIG. 11, the main part of the toner tank 20 includes a cylindrical tank case 21 having a bottom at the bottom in the figure, a cover 22 fixed above and sealing the toner. A plurality of agitators 2 each having a plurality of blades 23b for stirring the toner, which are rotatably sealed together with the toner by a tank case 21 and a cover 22.
And 3.

On the other hand, in order to drive the endless coil spring 31 for circulating the toner in the direction of the arrow in FIG. 12, the unit upper case 17 and the unit lower case 18 are driven.
The endless coil spring 31 enclosed so as to be able to circulate by means of the coil spring 3
One drive means 25 is arranged. The driving means 25
It has a projection 25a projecting from the unit upper case 17, and the upper end of the projection 25a is formed in a wedge shape. When the toner tank 20 is mounted at a predetermined position, the wedge-shaped convex portion 25a and the concave portion 23c formed at the lower end of one agitator 23 are engaged, and the agitator is driven to rotate. ing.

The driving means 25 of the endless coil spring 31 that circulates and conveys the toner can be driven by a rotating body that can be engaged with the coil spring 31. In this embodiment, the coil spring 31 is stretched. The engagement relationship with the coil spring 31 is stabilized by using a helical gear having a torsion angle that is close to the lead angle in the set state.

One agitator 2 driven by the above configuration
3 and the other end of the agitator 23, a gear portion 23a is formed.
Are connected by rotation.

The toner agitated by the rotation of the agitator 23 circulates through the opening 21a formed in the bottom of the tank case 21 and the opening 17a of the unit upper case 17 provided opposite the opening 21a. The endless coil spring 31 to be conveyed falls under its own weight in the toner circulation conveyance path. The opening 21a and the opening 17a are opened / closed (not shown) in conjunction with the attachment / detachment of the toner tank 20.

The toner dropped by its own weight into the toner circulating conveyance path in which the coil spring 31 is disposed
When the toner is circulated and transported in the direction of the arrow in FIG. 12 to move to the toner storage unit 11 by the drive of the drive unit, the weight falls from above the supply roller 13 and is stored in the storage unit 11 as shown in FIG. Since the toner storage unit 11 is configured to be very narrow, the toner storage unit 11 may be full due to the relationship between the toner consumption and supply depending on the image form. In this state, the toner may fall under its own weight. Instead, the toner is circulated and conveyed by the coil spring 31, and the drop of the toner from the toner tank 20 by its own weight is also interrupted.

The main part of the image forming means of this embodiment has been described above. The image forming unit U1 is detachably mountable to the main body, and is detached integrally for maintenance or replacement during maintenance. ing.

As for the relationship between the image forming unit U1 and the main body, as shown in detail in a part of FIG. 11, on the other hand, a concave portion 18a is formed in the unit lower case 18 as a portion to be positioned which is positioned based on the reference. The main frame 1 serving as a reference for the internal configuration of the apparatus is provided in the recess 18a.
The convex portion 100a as a positioning portion formed at the position 00 is engaged to perform predetermined positioning in the height direction and in the horizontal plane direction.
00b, a predetermined position in the height direction is determined, and the main frame 10 is fixed by fixing means such as screws (not shown).
It is fixed to 0. Further, as shown in FIG. 3, a bent portion 101g in the horizontal direction is formed on an upper part of a sheet metal member 101 constituting a drive unit U3 (described later), and the image forming unit U1 is formed on the bent portion 101g.
Is mounted and fixed by an appropriate fixing means (for example, a screw). That is, the bent portion 101g forms a positioning portion of the image forming unit U1.

As shown in FIGS. 1, 3, and 12, the main frame 100 has a sheet metal structure in this embodiment. As shown in FIG. 1, the first surface 10 becomes a mother surface having a sheet metal structure, and is referred to as a first surface 100c for positioning and holding an exposure unit U2, which will be described in detail later.
The second surface 1 which is bent into an L-letter shape from 0c to position and hold the unitized fixing unit 60, unitized sheet feeding unit 70, and unitized transfer unit 80, which will be described in detail later.
Then, as shown in FIGS. 3 and 12, the left and right ends are bent in the same direction as the second surface 100d so as to be orthogonal to the first surface 100c and the second surface 100d. This is a sheet metal integrated structure in which a surface 100e (the left side is omitted from the alternate long and short dash line in FIGS. 3 and 12, but has the same configuration as the right side and the third surface 100e is formed). The third surface 100e is L-shaped when viewed from the side (see FIG. 7).

The first surface 100c and the second surface 10
0d and the third surface 100e are positioned relative to each other, and in order to increase the rigidity, an opening is formed in a part of the third surface 100e, and a convex portion engageable with this opening is formed in a part of the second surface 100d. Are formed, and the third surface 100e has a connecting portion 100f in which both are fitted in the process of bending the third surface 100e. Thereby, the positional relationship among the first surface 100c, the second surface 100d, and the third surface 100e can be reasonably achieved with high accuracy, and the rigidity is also high due to the effect of the coupling portion 100f.

Although the connecting portion 100f is effective even if it is a mere fitting of both, in the present embodiment, in order to further increase the stability, the connecting portion 100f is subjected to a caulking fastening treatment. is there.

Next, the transfer section 80 for transferring the reversal-developed toner image to the image exposure section of the photosensitive drum 1 will be described with reference to FIG.

The main part of the transfer unit 80 of this embodiment is pressed toward the photosensitive drum 1 with a total pressure of several hundred g toward the photosensitive drum 1 by a pressing mechanism (not shown). A means for applying a bias of about DC 1 KV having a polarity opposite to that of the reversal-developed toner image is provided, and a rotatable transfer roller 81 formed of a conductive or semiconductive elastic material such as rubber, And a sheet material transport base 71 that supports the transfer roller 81, as well as the main components of the sheet material transport unit 70 described in detail below. The sheet material transport base 71 is positioned at a predetermined position by engagement of the positioning portion 71a with a positioning portion formed on the main frame 100, which is a reference for the internal configuration of the apparatus, and is fixed to the main frame 100 by fixing means such as screws. Have been.

The toner image conveyed to the nip formed by the pressing action between the photosensitive drum 1 and the transfer roller 81 is the same as the sheet fed from the sheet conveyer 70 described later in detail. And transferred.

Next, the fixing section 60 for feeding the sheet material on which the toner image on the photosensitive drum 1 is transferred and fixing the sheet material will be described.

The main part of the fixing section 60 of this embodiment is composed of a fixing roller 63, a pressure roller 67, an operation lever 68, a cam 69, a paper discharge roller pair 61, and a fixing base 64. I have.

The fixing roller 63 is disposed on the downstream side in the sheet material conveying direction, and is rotatable with a built-in heating element such as a halogen heater as a heating means in a hollow portion of the aluminum pipe material.

The pressure roller 67 is a fixing roller formed by a pressing mechanism comprising a lever 66 which can be displaced by being pressed by a pressing member such as a spring as a pressing means for pressing the toner image transferred onto the sheet material onto the sheet material. It is pressed with a total pressure of several kg toward 63. Pressure roller 6
Numeral 7 has at least a surface formed of a semiconductive elastic body such as silicon rubber, and is configured to be rotatable at the same peripheral speed as the fixing roller 63.

The toner image transferred from the transfer unit 80 to the sheet material and conveyed to the nip formed by the pressing action of the fixing roller 63 and the pressure roller 67 is transferred to the sheet at the predetermined temperature at the nip. Be established.

The operating lever 68 is rotatable between a position shown by a solid line in FIG. 1 and a position shown by a two-dot chain line in FIG. 1 to release the pressing force of the pressing mechanism, and can be operated from the front of the apparatus. It is.

The cam 69 is displaced in the direction of the arrow in FIG. 1 in conjunction with the rotation of the operation lever 68, and when it is rotated in the counterclockwise direction in the figure, the pressing by the pressing mechanism is released. I have.

The paper discharge roller pair 61 discharges the sheet material on which the image is fixed after passing through the fixing roller 63 and the pressure roller.

The fixing base 64 supports the above components, and the fixing unit 60 is unitized by the fixing base 64. The fixing base 64 is positioned at a predetermined position by engagement of the positioning portion 64a with a positioning portion formed on the main frame 100 which is a reference of the internal configuration of the apparatus, and is fixed to the main frame 100 by fixing means such as a screw. Have been.

Next, the paper feeding section 70 for feeding a sheet material such as paper toward the transfer section 80 will be described.

A sheet tray 72, which stores a large number of sheets of paper P such as paper, is disposed at the rear of the apparatus.
A well-known pressing mechanism 74 that selectively presses the sheet material P toward a rotatable sheet feeding roller 73 of a sheet feeding unit 70 formed of a high friction resistance material such as rubber is provided. It is detachably supported.

The paper supply section 70 on the apparatus main body side includes the above-described sheet material transport base 71, paper supply roller 73, sheet material feeding control mechanism 75, sheet material guide 76, and sheet material detecting means 77. It is configured.

The sheet feeding control mechanism 75 is disposed to face the sheet feeding roller 73 with the sheet P interposed therebetween, and only the uppermost one of the many sheets P is fed to the sheet feeding roller 7.
The sheet material is separated so that the sheet material is fed by the rotation of No. 3, and the second and subsequent sheet materials are not fed.

The sheet material guide 76 is disposed to face the sheet material transport base 71, and guides the sheet material toward the transfer section.

The sheet material detecting means 77 is disposed in the sheet material conveying path, and has a photo sensor for detecting the presence or absence of the sheet material.

The sheet conveying base 71 is provided with a transfer roller 8.
1 as well as the main components of the sheet conveying section 70.

Although not shown, the sheet conveying base 71 is provided with a pressing force releasing mechanism, such as a link mechanism, which operates in conjunction with the operation of the operation lever 68 operable from the front of the fixing unit 60. Connected by means,
A mechanism for releasing the pressing of the transfer roller 81 against the photosensitive drum 1 in conjunction with the operation of the operation lever 68 is provided.

The sheet feeding section 70 and the transfer section 80 are unitized by a sheet material transport base 71. As described above, the sheet material transport base 71 is a positioning section formed on the main frame 100 which is a reference of the internal structure of the apparatus. Is positioned at a predetermined position by engagement of the portion 71a to be positioned, and is fixed to the main frame 100 by fixing means such as screws.

When the paper feed roller 73 is driven to rotate in the above-described configuration, one sheet material follows the sheet material conveyance path and is fed to the transfer unit 80 described above.

Here, the sheet material feeding control will be described.

The sheet feeding roller 73 is rotated and driven by a desired command to feed one sheet material into the sheet material conveying path, and the sheet material is supplied to the sheet feeding roller 73 in accordance with a detection signal of the sheet material detecting means 77.
Stops in a state where the sheet material is sandwiched, and waits for the above-described transfer (standby).

The stop timing of the paper feed roller 73 may be stopped by a detection signal of the sheet material detecting means 77, but is stopped after a predetermined time elapses from the detection signal by a delay means such as a timer. May be. That is, the toner image reversely developed on the image exposing portion of the photosensitive drum 1 in the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 against each other is rotated by the rotation of the photosensitive drum 1.
The time required to reach the transfer unit 80 having the nip formed by pressing the transfer roller 81 and the transfer roller 81, and the time required to feed the sheet material from the standby state and reach the transfer unit 80 are desired. It suffices if the relationship can be controlled, and the present embodiment employs the latter.

In this embodiment, a sheet material detecting means 77 including a photo sensor for detecting the presence or absence of a sheet material is arranged in the sheet material conveying path of the sheet feeding section 70, and the other is omitted from the drawing. A second sheet material detection unit similar to the sheet material detection unit 77 is provided downstream of the nip formed by the pressing action of the fixing roller 63 and the pressure roller 67 of the fixing unit 60 in the sheet material conveyance direction. And
The sheet conveyance state is detected, and the detection signals from the sheet detection means 77 and the second sheet detection means are processed in a predetermined relationship to monitor the jam state in the apparatus.

The image forming apparatus according to the present embodiment is compactly configured, and can perform jam processing as follows. In the case of a paper jam in the paper feeding unit 70, the sheet material is pulled out to the rear of the apparatus. When the fixing unit 60 is in a jam state, the pressing force of the pressing roller 67 against the fixing roller 63 and the pressing of the transfer roller 81 against the photosensitive drum 1 are released by operating the operation lever 68 operable from the front of the apparatus.
Pull out the sheet material to the front of the device.

Next, the exposure unit U2 for exposing the photosensitive drum 1 to a latent image will be described.

The main part of the exposure unit U2 is 10,000 thousands r
pm, a control circuit board (not shown) for controlling the rotation of the motor 41, and light emitted from a light emitting element such as a semiconductor laser or the like, which is mounted on the output shaft of the motor 41 and rotates and is not shown. A deflection scanning means 43 for deflecting and scanning the beam, a reflection mirror 44 for irradiating the light beam 49 toward the photosensitive drum 1 and the like, and a case 42 which accommodates and constitutes the above-mentioned main components as a unit. I have. The case 42 is positioned at a predetermined position by engagement of the positioning portion 42a with a positioning portion formed on the main frame 100, which is a reference for the internal configuration of the apparatus, and is fixed to the main frame 100 by fixing means such as screws. .

The deflection scanning means 43 enables small and inexpensive optical scanning as described in detail in Japanese Patent Application No. 5-121995 filed by the present applicant. is there. In this embodiment, the optical path length from the deflection scanning unit 43 to the photosensitive drum 1 is set to approximately 200 mm.
A short optical path length of about 140 mm is also possible.

Next, a description will be given of the control unit 50 which controls the above-described units.

The main part of the control unit 50 is arranged at the lowermost end of the apparatus. At least a power supply circuit unit and operation control circuit units of each unit are arranged. Although not shown, an interface connector for receiving an external signal and a power supply unit are provided. A connection unit such as an input connector for input / output is connected, and the control unit 50 is compactly and centrally arranged.

The main part of the control unit 50 is the main frame 10
The main frame 100 is arranged below the second surface 100d of the drive unit 100 and grounded together with a conductive sheet metal member of the drive unit, and forms a shield for electromagnetic noise generated inside the control unit.

[0104] The driving relationship of each of the above-described structural parts will be described with reference to FIGS. 2 and 3, 6, and 7, 8, 9, 9, 10, 11, 12, and 13. I do.

As shown in FIG. 2 and FIG. 12, the main part of the drive transmission portion of this embodiment is concentrated on the right side surface of the main frame 100, that is, the third surface 100e. A first receiver 101 and a second wheel train receiver 102 are provided to face each other. The two wheel train receivers are provided with a drive motor 103 having a drive gear 103a on an output shaft and several kinds of rotating parts described in detail later. The drive gear train is rotatably supported to form a unit configuration (this unit is referred to as a drive unit). The drive unit U3 is positioned at a predetermined position by the engagement of the positioning portion with the positioning portion formed on the third surface 100e of the main frame 100, which serves as a reference for the internal configuration, and is fixed to a fixing means such as a screw 104 (FIG. 8). Has been fixed by.

In this embodiment, the first wheel train 101 and the second wheel train 102 are formed of sheet metal members, and will be described later in detail. It constitutes a mounting structure for rotating parts. The first train wheel receiver 101 and the second train wheel receiver 102 are fixed by screws 106 or the like as shown in FIG.

The drive motor 103 of this embodiment is
An inexpensive PM stepping motor is used, and smooth continuous rotation drive is enabled by controlling input pulses and current.

Referring to FIG. 6 and FIG. 7, the whole of the drive system of this embodiment will be described.

FIG. 6 shows the above-mentioned first wheel train 101 and the second wheel train 102, and FIG. 7 shows each gear train by omitting the two wheel train receivers for simplicity. It is easy to see. In both FIGS. 6 and 7, the center of rotation of each gear is indicated by a “+” mark in the figures (the same applies to FIGS. 11 and 13).

Referring to FIG. 7, the drive system of this embodiment will be described for each individual drive system after the common A # gear driven by the drive gear 103a provided on the output shaft of the drive motor 103. .

<First Driving System> The first driving system is for rotating and driving the above-mentioned photosensitive drum 1, and is provided with an A # gear.
The gears are driven in the order of J # gear → K # gear → L # gear.

The L # gear is a gear fixed to one end of the photosensitive drum 1 by, for example, a fixing means such as an adhesive. The L # gear is formed integrally with the photosensitive drum 1 and is attached to and detached from the image forming unit U1. Connected or disconnected from one drive system.

The attachment / detachment of the image forming unit U1 of this embodiment is performed by moving the image forming unit U1 in the vertical direction in the figure.

<Second Drive System> The second drive system is for rotating and driving the developing sleeve 12 which is a main component of the developing section 10 described above. A # gear → B # gear → C # gear → The gears are driven in the order of F # gear → G # gear.

The G # gear is a gear fixed to the protruding end of the support portion 12a extending to one end of the developing sleeve 12 by a fixing means such as press-fitting. Connected or disconnected from the second drive system.

<Third Drive System> The third drive system is for rotating and driving the supply roller 13, which is a main component of the developing unit 10, and is A # gear → B # gear → C # gear → The gears are driven in the order of D # gear → E # gear.

The E # gear is a gear fixed to the protruding end of the support portion 13a extending to one end of the supply roller 13 by fixing means such as press-fitting. Connected to or disconnected from the third drive system.

<Fourth Driving System> The fourth driving system is an endless coil spring 3 for circulating and conveying the toner.
1 for driving the agitator 23 of the toner tank 20 via the driving means 25. The A # gear → B # gear → C # gear → F # gear → H # gear → The gears are driven in the order of V # gear (V # gear is shown in FIG. 6).

The V # gear is a helical gear fixed to one end of the driving means 25 by a fixing means such as press-fitting, and the H # gear for driving the same rotates on the lower case 18 of the image forming unit U1. The helical gear is freely supported, and the H # gear is connected to or disconnected from the fourth drive system when the image forming unit U1 is attached or detached.

<Fifth Drive System> The fifth drive system is for rotating the above-described paper feed roller 73, and is driven in the order of A # gear → B # gear → M # gear → N # gear. .

The N # gear is a gear mounted on a clutch disposed at one end of the paper feed roller 73, and is always connected to the fifth drive system.

<Sixth Drive System> The sixth drive system is for rotating the fixing roller 63 described above, and is driven in the order of A # gear → P # gear → Q # gear → R # gear.

The R # gear is a gear provided at one end of the fixing roller 63, and is always connected to the sixth drive system.

<Seventh Drive System> The seventh drive system is for rotating and driving the above-described paper discharge roller pair 61, and is A # gear → P # gear → S # gear → T # gear → U # gear. Are driven in this order.

The U # gear is a gear provided at one end of the above-described paper discharge roller pair 61, and is always connected to the seventh drive system.

As described above, in the drive system according to the present embodiment, each main part is driven in a distributed manner while avoiding the concentration of the rotational driving force.

Next, the main parts of each of the drive systems will be described in detail.

<First Drive System> The first drive system drives the photosensitive drum 1 to rotate as described above, and is driven in the order of A # gear → J # gear → K # gear → L # gear. The structure is shown in FIGS. FIG. 8 is a developed sectional view of the first drive system.

The drive gear 103a provided on the output shaft of the drive motor 103 mounted on the first wheel train 101 is formed on each of the first wheel train 101 and the second wheel train 102 with their inner surfaces mirrored. Burring portions 101a and 10
Drive the A # gear rotatably supported by 2a,
Further, the first train wheel provided opposite the second train wheel receiver 102.
The K # gear is driven via the J # gear rotatably supported via the push Ja pressed and held in the projection portion 101b of the receiver 101, and the L # gear is further driven.

As described above, the L # gear is connected to or disconnected from the drive system by the attachment / detachment of the image forming unit U1, so that the engagement between the K # gear and the L # gear is facilitated in this embodiment. As a means, K
The # gear has a double structure having a K1 # gear and a K2 # gear. The K1 # gear is a burring portion 1 formed on the first wheel train 101 with a mirror-finished inner surface similarly to the A # gear.
01c is rotatably supported. The K2 # gear is provided with one end thereof opposed to the first train wheel receiver 101, and has a wheel train second receiver 10 having an outer peripheral portion formed in a mirror-finished state.
2 is supported by the projection unit 102b, and the other end is
It is inserted inside the K1 # gear and is rotatably supported. The K1 # gear and the K2 # gear are integrally rotatable. In the figure, K1 # gear and K2 # gear 2
As shown in the cross-sectional views as viewed from A (FIGS. (B) and (c)), the heavy structure portion has a concave portion K1 # a and a convex portion K1 # b formed in a K1 # gear at point-symmetric positions, respectively, Recess K in gear
2 # a and the convex portion K2 # b are formed at point-symmetric positions, respectively. The concave portion and the convex portion of the K1 # gear and the K2 # gear are inserted into each other, and both the convex portions K1 # b and K2 #B and a compression spring KS. Therefore, K1
The # gear and the K2 # gear are relatively rotatable by a predetermined angle with each other, and when no external force is applied, the state shown in FIG. 3C is maintained by the urging force of the compression spring KS. However, when the K1 # gear is driven in the direction of the arrow in the figure, as shown in FIG. 3B, the protrusion K1 # b of the K1 # gear and the protrusion K2 # b of the K2 # gear are moved. The formed second convex portions K1 # c and K2 # c abut against the urging force of the compression spring KS, and the K2 # gear is driven.

According to such a double structure, when the image forming unit U1 is mounted, the K # 2 gear is in the L position.
#Because it is engaged with the gear and has a rotating load,
When the 1 # gear is rotationally driven in the direction of the arrow in the figure, the K2 # gear is stopped, the compression spring KS is compressed, and only the K1 # gear rotates, as shown in section A in FIG. as,
Within a short time, the second convex portions K1 # c and K2 # of the K1 # gear
The second convex portion K2 # c of the gear comes into contact with the gear, the K2 # gear is driven to rotate in the direction of the arrow in the figure, and the L # gear is driven in the direction of the arrow in FIG.

After the L # gear is driven in the direction of the arrow in FIG. 11, the rotation is stopped, and the image forming unit U1 is moved to the position shown in FIG.
When the gear # 1 is taken out upward, the L # gear and the K2 # gear are arranged at positions where they can be disengaged from each other, so that their meshing is disengaged without difficulty and the rotational drive load of the K2 # gear is released. Then, the compression spring KS expands to move the K2 # gear to the position shown in FIG.
Rotate in the direction of the arrow as shown in (c), and return to the state shown in FIG.

On the other hand, when the image forming unit U1 is mounted from above in FIG. 11 in the state shown in FIG.
Since the gear has a rotationally driven load generated by the pressure contact between the photosensitive drum 1 and the developing sleeve 12, the L # gear becomes K2 # when the L # gear and the K2 # gear are engaged. The gear is mounted in a direction opposite to the normal rotation direction, that is, by rotating the K2 # gear in FIG. 11 clockwise by a predetermined angle against the extension force of the compression spring KS. Note that the second convex portion K1 # c and the second convex portion K2 #
FIG. 8C is configured such that the state shown in FIG. 8B is not reached even if the K2 # gear rotates clockwise by a predetermined angle when the image forming unit U1 is mounted.

<Second Drive System> The second drive system is for rotating and driving the developing sleeve 12, which is a main component of the developing unit 10, as described above. The gears are driven in the order of # gear → F # gear → G # gear.
The structure is shown in FIGS. 9, 10 and 11. 9 and 10 are expanded sectional views of the second drive system.

The relationship between the first gear train 101, the drive motor 103, the first gear train 101, the second gear train 102, and the A # gear is the same as that of the first drive system, and therefore the description is omitted. A description will be given of the driving after the #gear.

The A # gear is connected to a C # gear via a B # gear rotatably supported via a push Ba press-fitted and held in a burring portion 102c provided on the second train wheel receiver 102, and further to a F # gear. The # gear (FIG. 10) is driven and its rotational drive reaches the G # gear. Here, the C # gear of FIG.
The C # gears of 0 are the same.

The B # gear is composed of a B1 # gear and a B2 # gear, and the B1 # gear and the B2 # gear are connected by press-fitting an oval-shaped engagement portion and an engaged portion shown in FIG. It is rotatable together.

[0138] The C # gear of the next gear train is the third gear, which will be described later.
B2 # also has a function to transmit and branch rotational drive to the drive system.
Driven from gears.

[0139] The main part of the C # gear is a wheel train second receiver 102.
Burring portion 102d formed with a mirror-finished inner surface
A tumbler arm C1 having a bearing function rotatably supported by the tumbler arm C1 and a tumbler arm C1 having a tumbler function to be described in detail later.
1. A burring portion 10 formed with a mirror-finished inner surface
The main shaft C2 rotatably supported by 1d and the tumbler arm C1 and a flange portion C2f of the main shaft C2 are guided in the thrust direction, and rotate under a double structure with the main shaft C2 described in detail later. A free C2 # gear and a C1 driven from the B2 # gear and coupled with the main shaft C2 by press-fitting an oval-shaped engaging portion and an engaged portion shown by C in FIG. And a # gear, and rotationally drives a G # gear from a C2 # gear via an F # gear.

The F # gear has an F1 # gear and an F2 # gear. The F1 # gear has a hole F1 # d at one end thereof, which is provided in the second train wheel receiver 102, and is supported by a projection portion 102e formed with the outer peripheral portion being mirror-finished, and a shaft portion F1 # e at the other end. It is rotatably supported by a burring portion 101e formed on the first wheel train wheel 101 with a mirror-finished inner surface. The F2 # gear is rotatably supported by a shaft portion F1 # e of the F1 # gear.

The F # gear has a double structure composed of an F1 # gear and an F2 # gear.
Like the K # gear of the drive system, the F1 # gear and the F2 # gear are integrally rotatable. The double structure of the F # gear will be described later in the section of the fourth drive system.

As described above, the G # gear is connected to or disconnected from the F1 # gear of the second drive system when the image forming unit U1 is attached or detached. As means for facilitating the meshing relationship, the C # gear has a double structure that performs the same operation as the K # gear of the first drive system.

That is, in FIG. 10, the double structure portion composed of the C2 # gear and the main shaft C2 is a sectional view taken along the line BB (FIGS. (B) and (c)).
As shown in the figure, the C2 # gear has a concave portion C2 # a and a convex portion C2 #.
b is formed at each point symmetric position, and the concave portion C2a and the convex portion C2b are formed at the point symmetric position on the main axis C2, respectively.
The concave and convex portions of the C2 # gear and the main shaft C2 are inserted into each other, and a compression spring CS (see FIGS. (B) and (c) in a simplified manner) is provided between the two convex portions C2 # b and C2b. (Drawn). Therefore, the C2 # gear and the main shaft C2 can relatively rotate by a predetermined angle with each other, and when no external force is applied, the state shown in FIG. 3C is maintained by the urging force of the compression spring CS. When the main shaft C2 is driven in the direction of the arrow in the figure, as shown in FIG.
#B and the second protrusion C2 formed on the protrusion C2b of the main shaft C2.
#C and C2c abut against the urging force of the compression spring CS, and the C2 # gear is driven.

According to such a double structure, when the image forming unit U1 is mounted, the C2 # gear is
Since the main shaft C2 is rotationally driven by the C1 # gear in the direction of the arrow in the figure because the main shaft C2 is in mesh with the G # gear via the 1 # gear, the C2 # gear is stopped and the compression spring is stopped. CS is compressed and only the main shaft C2 rotates, and B
As shown in section B in FIG. B (FIG. (B)), the second convex portion C2 # c of the C2 # gear and the second convex portion C of the main shaft C2 within a short time.
2c is brought into contact, the C2 # gear is rotationally driven in the direction of the arrow in the figure, and the G # gear is driven via the F1 # gear.

After the rotation of the G # gear is stopped and the image forming unit U1 is taken out upward in FIG. 11, the G # gear and the F1 # gear are arranged at positions where they can be disengaged from each other. So, the meshing can be easily separated and F
The rotational drive load of the C2 # gear is released together with the 1 # gear. Then, the compression spring CS is extended, and the C2 # gear is moved to the position shown in FIG.
It is rotated in the direction of the arrow as shown at 0 (c) and returns to the state shown in FIG.

On the other hand, when the image forming unit U1 is mounted from above in FIG. 11 in the state shown in FIG.
Since the # gear has a rotationally driven load generated due to the pressure contact between the photosensitive drum 1 and the developing sleeve 12 or the pressure contact between the developing sleeve 12 and the regulating blade 14 and the supply roller 13, the G # gear is driven by the F1. In the process of meshing with the # gear, the G # gear moves the C2 # gear via the F1 # gear in the direction opposite to the normal rotation direction, ie, against the extension force of the compression spring CS as shown in FIG. The C2 # gear is mounted by rotating the C2 # gear clockwise by a predetermined angle.
The second convex portion C2 # c and the second convex portion C2c are shown in FIG. 10B even if the C2 # gear rotates clockwise by a predetermined angle when the image forming unit U1 is mounted. It is configured not to reach the state.

<Third Drive System> The third drive system is, as described above, a supply roller 1 which is a main component of the developing section 10.
3 to rotate and drive A # gear → B # gear →
The gears are driven in the order of C # gear → D # gear → E # gear. The structure is illustrated in FIGS. 9, 10 and 11. 9 and 10 are developed sectional views of the third drive system.

The driving from the driving motor 103 to the C # gear is the same as that described in the second driving system, so that the description is omitted, and the driving from the C # gear will be described.

As described above, the C # gear has the rotation drive transmission branch function of the second drive system and the third drive system, and
Driven from 2 # gear.

A tumbler arm C1 having a bearing function and a tumbler function of the main shaft C2, one end of which is rotatably supported by a burring portion 102c formed on the second train wheel receiver 102 with its inner surface being mirror-finished is shown in FIG. The other end has a bearing C1a at the other end for rotatably supporting the D # gear. The bearing portion C1a is inserted through a circular opening 102f formed in the second train wheel receiver 102, and the tumbler arm C1 is rotatable by both play spaces.

The bearing C of the tumbler arm C1
1a rotatably supported by the D # gear,
Driven by 1 # gear drives E # gear.

Here, C1 # gear, tumbler arm C
1 and a planetary drive mechanism including a D # gear will be described.

In FIG. 11, in the planetary drive mechanism of the present embodiment, the C # gear (C1 # gear) is driven to rotate in the direction of the arrow in the figure, and the pressure of the gear at the meshing point between the C1 # gear and the D # gear. The tumbler arm C1 is rotated and urged by the friction between the main shaft C2 and the tumbler arm C1 which are driven to rotate in the angular direction and the direction of the arrow in FIG. This is a configuration in which the planetary gear moves in a direction approaching the E # gear while performing planetary movements that rotate and revolve. This planetary urging action is performed even if there is a load on the E # gear.
In addition, the tumbler arm C1 operates even if it is not provided.
This is a structure in which the movement is restricted by the planetary urging movement by an amount corresponding to the gap with respect to 1a.

In this planetary drive mechanism, the D # gear and the E
As a means for stabilizing the meshing state with the # gear, in this embodiment, a first circumferential portion D coaxial with the gear portion is provided on a part of the D # gear.
#A, and a second circumferential portion E # a which is also coaxial with the gear portion is formed in a part of the E # gear, and both circumferential portions are in contact with each other to be rotatable. is there. This first circumferential portion D # a
The distance between the pitches in the contact state between the second circumferential portion E # a and the second circumferential portion E # a is D
The relationship is such that an appropriate backlash occurs in the meshing state between the # gear and the E # gear.

Here, as described above, the E # gear is connected to or disconnected from the D # gear of this drive system by the attachment / detachment of the image forming unit U1, so the attachment / detachment of the image formation unit U1 will be described.

In the above configuration, the C # gear (C1 # gear) is shown in FIG.
When the rotation is stopped after driving in the direction of the middle arrow 1, the D # gear and the tumbler arm C1, which have been biased by the planetary drive mechanism, are released from the biasing force and enter a free state. For this reason, when taking out the above-mentioned image forming unit U1 upward in FIG.
It is extremely easy to remove the image forming unit U1 by moving away from the gear.

On the other hand, when the image forming unit U1 is mounted from above in FIG. 11 in a state after the image forming unit U1 is taken out, the D # gear and the E # gear are in a state of meshing or having a clearance. However, as described above, the C # gear (C
When the # 1 gear is driven in the direction of the arrow in FIG. 11, the D # gear moves toward the E # gear while carrying out the above-mentioned planetary motion, with or without the load of the E # gear. And both gears mesh with each other.

Also, when the D # gear is moving in the direction approaching the E # gear, the image forming unit U1
When the D # gear and the tumbler arm C1 are mounted from above in the middle, the D # gear and the tumbler arm C1 are released from the urging force and are in a free state, so that the D # gear moves to a predetermined position while engaging with the E # gear.

Next, when the D # gear meshes with the E # gear,
The case where a predetermined rotational load is applied to the #gear and the gear is driven to rotate will be described.

As the rotational load increases, D #
Particularly, the planetary movement urging force on the gears increases in the direction of the pressure angle of the gear at the meshing point between the C1 # gear and the D # gear, and the D # gear approaches the E # gear. However, the above-mentioned first circumferential portion D #
The urging movement is regulated by the contact state between the gear a and the second circumferential portion E # a, and the meshing between the D # gear and the E # gear is rotationally driven with an appropriate backlash.

<Fourth Drive System> The fourth drive system is for driving the drive means 25 for driving the endless coil spring 31 for circulating and conveying the toner and the agitator 23 of the toner tank 20 as described above. And A
# Gear → B # gear → C # gear → F # gear → H # gear → V
# Gears (shown in FIG. 6). Its structure is
This is shown in FIGS. 9, 10 and 11. 9 and 1
Reference numeral 0 is a developed sectional view of the fourth drive system.

The driving from the driving motor 103 to the F1 # gear is the same as that described in the second driving system, and therefore the description is omitted, and the driving from the F1 # gear will be described.

As described in the section of the second drive system, the F # gear is constructed in a double structure having the F1 # gear and the F2 # gear like the C # gear, and the F2 # gear is H # The gear is driven to drive the V # gear.

Here, as described above, the H # gear is driven by the attachment / detachment of the image forming unit U1 to the F2 of the fourth drive system.
In this embodiment, the F # gear is connected to or disconnected from the F # gear as a means for facilitating the meshing relationship between the F2 gear and the H # gear.
A structure that performs the same operation as the C # gear of the drive system is adopted.

That is, in FIG. 10, the double structure portion of the F1 # gear and the F2 # gear has a concave portion F1 # a in the F1 # gear as shown in the BB sectional views (FIGS. (B) and (c)). The convex portions F1 # b and the convex portions F2 # a and the convex portions F2 # b are formed at point-symmetric positions in the F2 # gear, respectively. The concave portion and the convex portion are inserted into each other, and a compression spring FS (illustrated simply in FIGS. (B) and (c)) is arranged between both the convex portions F1 # b and F2 # b. It has a structure. Therefore, F
The 1 # gear and the F2 # gear can rotate relative to each other by a predetermined angle, and when no external force is applied, the state shown in FIG. 3C is maintained by the urging force of the compression spring FS. However, when the F1 # gear is driven in the direction of the arrow in the figure, as shown in FIG. 3B, the protrusion F1 # b of the F1 # gear and the protrusion F2 # b of the F2 # gear are provided. The second convex portions F1 # c and F2 # c formed in the above-mentioned form abut against the urging force of the compression spring FS, and the F2 # gear is driven.

According to such a double structure, when the image forming unit U1 is mounted, the F2 # gear is set to the H
#Because it is engaged with the gear and has a rotational load,
When the 1 # gear is rotationally driven by the C2 # gear in the direction of the arrow in the figure, the compression spring FS is compressed while the F2 # gear is stopped, and only the F1 # gear is rotated.
As shown in FIG. 7B, the second convex portion F1 # c of the F1 # gear and the second convex portion F2 # c of the F2 # gear abut within a short time, and the F2 # gear is moved in the figure. The H # gear is driven by rotation in the direction of the arrow.

When the rotation of the H # gear is driven and then the rotation is stopped, and the image forming unit U1 is taken out upward in FIG. 11, the H # gear and the F2 # gear are arranged at positions where they can be disengaged from each other. So, the meshing can be easily separated and F
The rotational drive load of the 2 # gear is released. Then, the compression spring FS expands, and the F2 # gear rotates in the direction of the arrow as shown in FIG. 10C, and returns to the state shown in FIG.

On the other hand, when the image forming unit U1 is mounted from above in FIG. 11 in the state shown in FIG.
The # gear has a rotationally driven load related to the driving means 25 and the like for driving the endless coil spring 31 via the V # gear, so that in the process in which the H # gear comes into mesh with the F1 # gear, The H # gear rotates the F2 # gear in a direction opposite to the normal rotation direction, that is, rotates the F2 # gear of FIG. 10C counterclockwise by a predetermined angle against the extension force of the compression spring FS. It will be mounted after being moved. In addition,
The second convex portion F1 # c and the second convex portion F2 # c are shown in FIG. 10B even if the F2 # gear rotates clockwise by a predetermined angle when the image forming unit U1 is mounted. It is configured not to reach the state.

By the way, when the image forming unit U1 is mounted, first, the H # gear and the F2 # gear mesh with each other.
Next, the G # gear and the F1 # gear may mesh with each other.
In this case, the above-mentioned operation by the double structure of the C # gear must be performed after the above-mentioned operation by the double structure of the F # gear. In the fourth drive system, the gear 2
Since the heavy structure is provided in series with the C # gear and the F # gear, the urging force of the compression springs CS and FS provided in the two gears between the C # gear and the F # gear is temporarily reduced. If the torque balance determined as one element is not set appropriately (for example, the spring force of the compression spring FS is too large compared to the spring force of the compression spring CS), the H # gear and the F
When the 2 # gear meshes with the F2 # gear and rotates in the counterclockwise direction in FIG. 3 (c), the rotation of the F2 # gear occurs even though the G # gear and the F1 # gear have not yet meshed. Accordingly, the F1 # gear also rotates counterclockwise, and the C2 # gear rotates clockwise so as to compress the compression spring CS, which is required when the G # gear and the F1 # gear mesh with each other. There is a possibility that a gap between the second convex portion C2 # c and the second convex portion C2c cannot be obtained.

Therefore, in this embodiment, first, the H # gear and the F
Even when the 2 # gear meshes and then the G # gear and the F1 # gear mesh, the desired operation of the double structure of the C # gear is not affected by the operation of the double structure of the F # gear, As done independently, ie, H
When the # gear and the F2 # gear mesh with each other and the F2 # gear rotates counterclockwise in FIG. 3C, the C2 # gear does not contract the compression spring CS and does not rotate clockwise. Thus, for example, the torque balance between the C # gear and the F # gear is set by making the spring force of the compression spring CS larger than the spring force of the compression spring FS.

When the image forming unit U1 is mounted, if the G # gear and the F1 # gear are engaged first, and then the H # gear and the F2 # gear are engaged, the above-mentioned inconvenience does not occur.

Next, the above-described drive gear train is supported to form a unit structure, and the third surface 100e of the main frame 100 is formed.
The relationship between the drive transmission unit (drive unit U3) fixed to and the driven unit on the image forming unit U1 will be described with reference to FIG.

In this embodiment, in the relationship between the drive section on the main body side and the driven section on the image forming unit U1 side, both of them have high rigidity so as to avoid the drive force or the concentrated drive force. This configuration is decentralized so that it can be made compact and inexpensive without the need.

The specific contents will be described below.

The working relationship between the force of the drive unit on the main body side and the force of the driven part on the image forming unit U1 side is determined by the direction of the pressure angle of the gear at the point of mesh between the drive gear on the main body side and the driven gear on the image forming unit U1 side. The following is shown for each drive system.

<First Driving System> The direction of action of the force for driving the L # gear from the K2 # gear is in the direction of the arrow L directed obliquely upward and to the left in the figure.

<Second Driving System> The direction of action of the force for driving the G # gear from the F # gear is the direction of the arrow G directed obliquely upward to the right in the figure, and the L # gear is driven from the K2 # gear. The direction of the force is different from the direction L of the force by the angle αG, and the specific angle in this embodiment is approximately 95 deg.

<Third Driving System> The direction of action of the force for driving the E # gear from the D # gear is the direction of the arrow E which is directed obliquely upward to the right in the figure, and drives the L # gear from the K2 # gear. The direction is different from the direction L of the force acting direction by the angle αE, and the specific angle in the present embodiment is approximately 55 deg.

<Fourth Driving System> The acting direction of the force for driving the H # gear from the F # gear is the direction of the arrow H which is directed obliquely upward to the right in the figure, and drives the L # gear from the K2 # gear. The direction differs from the force acting direction arrow L by an angle αH, and the specific angle in this embodiment is approximately 85 deg.

As described above, in the present embodiment, the developing sleeve 12 which is a main part of the developing unit 10 described above corresponds to the acting direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear.
The action directions of the supply roller 13, the driving means 25 for driving the endless coil spring 31 for circulating and transporting the toner, and the force for rotating and driving the agitator 23 of the toner tank 20 are different from each other. Since the positions where the forces are applied are dispersed, the driven portion on the image forming unit U1 side or the driving portion on the main body side has a structure that does not need to be configured with high rigidity.

The above is the relationship for each drive system in this embodiment, which is configured so as not to concentrate the driving force on the main body side or the driven force on the image forming unit U1 side.

On the other hand, when the above-mentioned respective driving forces are combined, it becomes a substantially arrow T direction which is directed obliquely upward in the figure, and the acting direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear is the angle αT. Only the direction is different, the action direction arrow L
And the action direction arrow T do not act in series, so that when the image forming unit U1 is fixed, the fixing force can be reduced.

The direction of the pressure angle of the gear at the meshing point between the driving gear on the main body side and the driven gear on the image forming unit U1 side is positive due to the attachment / detachment of the image forming unit U1 or the variation in the configuration of each component. Minus 15d
In this embodiment, at least the driving force acting in the substantially arrow T direction is different from the acting direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear. It is configured to act in a different direction beyond a region parallel to the lines L1 and L2 shown in FIG. 13 which differs by more than ± 15 deg.

Next, attention will be paid to the relationship between the driving force acting on the developing sleeve 12 and the supply roller 13 constituting the main part of the developing unit 10 and the structure of the developing unit 10.

As described above with reference to FIG. 4, FIG. 5 and FIG. 12, the supporting members 5 and 5 which rotatably support both ends of the supply roller 13 and the developing sleeve 12, which are main parts of the developing section 10, respectively. As shown in FIG.
As shown in FIG. 2, it is rotatably supported by the support pin 7 and is configured to be rotatable integrally with the photosensitive drum 1 with the support pin 7 as a support shaft together with the above-described regulating blade 14.

By the action of the driving force acting on the second drive system in the direction of arrow G and the drive force acting on the third drive system in the direction of arrow E shown in FIG. Is pivoted in the direction of arrow 110 in the figure, that is, the direction in which the developing unit 10 is separated from the photosensitive drum 1.

Therefore, according to the above configuration of the present embodiment,
The nip width between the photosensitive drum 1 and the developing sleeve 10 does not become excessively large due to the occurrence of a biting phenomenon in the rubbing nip portion between the photosensitive drum 1 and the developing sleeve 12, and the nip width is stabilized. Since the positions are dispersed and there is no concentrated load on the driven unit on the image forming unit U1 side or the driving unit on the main body side, the driven unit on the image forming unit U1 side or the driving unit on the main body side However, the vibration and chatter can be suppressed and the driving with less rotation jitter can be performed without necessarily having a high rigidity.

In this embodiment, as described above, the main part of the developing section is urged to rotate about the support pin 7 in the direction of arrow 110 in the figure, that is, in the direction away from the photosensitive drum 1. Since the springs 8, 8 are provided to apply the tension to the support members 5, 5 to urge the developing sleeve 12 toward the photosensitive drum 1, a stable nip between the developing sleeve 12 and the photosensitive drum 1 is formed. .

According to the present embodiment as described above, the following operational effects can be obtained.

(I) According to the mounting structure of a gear or the like as a rotating component in the present embodiment, the rotating member is rotatably supported by a burring portion and / or a projection portion formed on a sheet metal member, and the burring portion and And / or increase the axial height of the projection part to at least twice the thickness of the plate 10
Since the mounting structure of the rotating component is about twice or less, the rotating component is rotatably supported by the burring portion and / or the projection portion. Therefore, according to such a structure, by forming the burring portion and / or the projection portion on the sheet metal member and supporting the rotating component on the burring portion and / or the projection portion, it is possible to rotatably mount the rotating component. This eliminates the need for the support shaft and the work of inserting and inserting the support shaft into the bearing portion and the bending of the tip of the burring portion as required in the above-described prior art. Therefore, an apparatus using such a structure can be reduced in size and cost, and can achieve stable operation. Further, in this embodiment, a burring portion or a projection portion is formed at each of opposing portions of the train wheel first receiver 101 and the train wheel second receiver 102, which are sheet metal members arranged to face each other, and a pair of sheet metal members is formed. Since the shafts or holes at both ends of the gears and the like disposed therebetween are rotatably supported by the burring portion or the projection portion, the shafts at both ends of the gears and the like are supported by the burring portions, or The holes at both ends are supported by the projection part, or the shaft part at one end is supported by the burring part, and the hole part at the other end is supported by the projection part.

In any case, according to the above-described structure, the burring portion and / or the projection portion are formed on the sheet metal member, and the gears and the like are supported by the sheet metal members as described above. Since the support shaft can be rotatably mounted, it is not necessary to install the support shaft and the work of inserting the support shaft into the bearing portion and to bend the tip of the burring portion, which are required in the above-described prior art.

Therefore, according to the image forming apparatus of this embodiment using such a structure, the size and cost can be reduced, and a stable operation can be obtained.

Further, since the supporting portion of the rotating component has a structure in which burring processing or projection processing is directly performed on the sheet metal member, and furthermore, a structure in which the rotating component is supported at both ends, the supporting shaft is implanted in the frame. By comparison, the strength of the support portion is improved, and it can withstand a large axial force (power). Therefore, such a structure is particularly effective when the number of rotating parts is large, that is, when a plurality of burring parts and / or projection parts are formed and a plurality of rotating parts are supported by a sheet metal member.

(Ii) Since the projection of the sheet metal member (eg, 102e in FIG. 10A) is rounded, a hole at the end of the rotating component (eg, FIG. 1) is formed.
It is easy to insert the projection part into the F1 # d) at 0 (a), and the assemblability is improved, and at the same time, the rotating parts (for example, the F1 # gear of FIG. 10A) are not damaged.

(Iii) Since the inner surface of the burring portion and the outer surface of the projection portion are mirror-finished, the slidability of the rotating component is improved, the torque loss is reduced, and the durability is improved.

(Iv) In the drive unit U, a pair of sheet metal members, ie, the first train wheel train 101 and the second train wheel train receiver 102 are fixed to the main frame 100.
Since the receiver 101 and the second train wheel receiver 102 form a part of the frame, the size and cost of the apparatus can be further reduced.

(V) The positional accuracy between the image forming unit U1 having the photosensitive drum 1 and the exposure unit U2 for exposing the photosensitive drum 1 to form a latent image is important for improving the image quality to be formed. . The positional accuracy between the photosensitive drum 1 and the drive unit U2 that rotationally drives the photosensitive drum 1 is important in improving the image quality by smoothly rotating the photosensitive drum 1 without vibration and reducing rotation unevenness.

According to the image forming apparatus of this embodiment, a part of the frame on which the image forming unit U1 and the exposing unit U2 are mounted is a part of the pair of sheet metal members of the drive unit U3, ie, the first train wheel receiver 101 and the train wheel. The second receiver 102 is used, and at least a part 101g (see FIG. 3) of the positioning portion of the image forming unit is a drive unit U.
3, the position accuracy between these three units is kept high, and a high-quality image is obtained.

That is, according to the image forming apparatus of the present embodiment, high quality images can be obtained while further reducing the size and cost.

(Vi) Since the frame including the sheet metal member of the drive unit U3 forms a shield for electromagnetic noise generated inside the apparatus, further reduction in size and cost can be achieved. (Vii) In the above embodiment, several kinds of rotatable drive gear trains supported by the pair of sheet metal members, ie, the first train wheel train 101 and the second train train receiver 102, are burring in accordance with the driving force share. The support portion of the rotatable shaft portion or the rotatable hole portion which engages with the projection portion receives a radial support load. In order to cope with this support load, the burring portion, Alternatively, set the height of the projection section in the axial direction to an appropriate amount. For example, the thickness is desirably about 2 to 10 times the sheet thickness (about 2 to 10 mm if the sheet thickness is 1 mm). On the other hand, in the mass production, the burring portion or the projection portion of the wheel train first receiver 101 and the wheel train second receiver 102 which are arranged opposite to each other also have a slight relative displacement. , In order to cancel this relative position shift and achieve stable gear support,
The height of the burring portion or the projection portion in the axial direction is set low. As a result, the height is set to be high for mass production in balance with the supporting load.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the present invention.

For example, in the description of the structure of the drive transmission unit, a rotatably supported gear has been described as an example. Instead of this gear, the description is omitted. The above-described effects of the present embodiment can be similarly exerted even with a so-called rotating body such as a pulley of a belt.

Further, it is more desirable that the mounting structure of the rotating component is a structure as in a modified example described below.

<Modification> FIG. 14 is a diagram showing a modification of the drive unit of the image forming apparatus described above. In the figure, parts corresponding to the above-described embodiments are denoted by the same reference numerals.

The feature of this modification is that the first train wheel 101
In addition, the supporting portions of the second wheel train 102 that support the rotating components at both ends are all constituted by projection portions having rounded tip portions.

According to FIG. 14, all of the supporting portions for supporting both ends of the A # gear and the K # gear are projection portions 101a ', 102a', 101 having rounded tips.
c 'and 102b'.

According to such a mounting structure, the assembling work becomes extremely easy. That is, for example, the train wheel first receiver 1
01 to the plurality of projection units 102a ′, 1
02b 'is set to the upper side, A # gear and K # gear are set in each projection part, and further, the second wheel train receiver 102 is set from thereabove, and these are set to appropriate means such as screws 106. It can be assembled simply by fixing with. Note that components that are not supported at both ends need to be incorporated in advance or later.

[0208]

According to the present invention, the size and cost of the apparatus can be reduced, and a stable operation can be obtained.

[0209]

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of an image forming apparatus according to the present invention, and is a cross-sectional view of a main part on the left side showing the entire configuration of the image forming apparatus.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 6;

FIG. 4 is a sectional view of a main part of a left side surface of the image forming unit (a sectional view taken along line IV-IV in FIG. 2).

FIG. 5 is a partially cut left side view of the image forming unit.

6 is a sectional view taken along the line VI-VI in FIG. 3;

FIG. 7 is a sectional view taken along line VII-VII in FIG. 3;

FIG. 8 is an exploded cross-sectional view illustrating a rotation drive transmission unit of the image forming apparatus, and also illustrates an example of a mounting structure of a rotating component.

FIG. 9 is an exploded cross-sectional view showing a rotation drive transmission unit of the image forming apparatus, and also shows an example of a mounting structure of a rotating part.

FIG. 10 is a developed cross-sectional view illustrating a rotation drive transmission unit of the image forming apparatus, and also illustrates an example of a mounting structure of a rotating component.

FIG. 11 is a sectional view of a main part on the right side showing the image forming unit U1.

FIG. 12 is a sectional view of a main part of the upper surface showing the image forming unit U1.

FIG. 13 is an explanatory diagram relating to rotational driving of the image forming unit U1.

FIG. 14 is an explanatory diagram of a modification.

FIG. 15 is an explanatory diagram of a conventional technique.

FIG. 16 is an explanatory diagram of a conventional technique.

FIG. 17 is an explanatory view of a conventional technique.

FIG. 18 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 101 first train wheel receiving 101d, 101e burring section 102 second train wheel receiving 102c, 102d burring section 102e projection section

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuhito Hirashima 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Akihiko Ikegami 3-5-5 Yamato, Suwa City, Nagano Prefecture Seikoー Epson Corporation

Claims (2)

[Claims] 1. A rotatable member is rotatably supported on a burring portion and / or a projection portion formed on a sheet metal member, and an axial height of the burring portion and / or the projection portion is twice or more and 10 times or more a sheet thickness. An image forming apparatus having a mounting structure for a rotating part having the following dimensions. 2. The image forming apparatus according to claim 1, wherein a plurality of the burring units and / or the projection units are formed, and a plurality of rotating parts are supported on the sheet metal member.