JPH07114271A - Image forming device - Google Patents

Abstract

PURPOSE:To facilitate the engagement/disengagement of the gear to be driven of a cartridge and the driving gear of a main body with simple structure and to realize a printer or a facsimile which is miniaturized and inexpensive. CONSTITUTION:The gear to be driven L# of the cartridge is driven by a gear K# provided in the main body; and the gear K# is constituted by combining a gear K1# and a gear K2# and coaxially and rotatably supported, and it is in an initial state where it is stopped after being energized to be turned in one direction by a spring KS by combining them through a means capable of relatively turning. When the gear to be driven L# is driven from the gear K1# through the gear K2#, the gear K1# is idly rotated and the gear K2# can be driven at a specified position, then the gear to be driven LIP is driven. When the gear to be driven L# is engaged with the gear K2#, they are engaged while the gear K2# is idly rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an image forming apparatus for forming an image on a sheet material such as a printer or a facsimile, and more particularly to a structure of an apparatus having a removable cartridge.

[0002]

2. Description of the Related Art As a typical example of a conventional image forming apparatus, a structure as shown in Japanese Unexamined Patent Publication No. 1-222270 is generally known. When the cartridge is attached or detached, the rotation drive unit on the device body side is linked to the attachment / detachment operation of the cartridge to facilitate the engagement between the rotation drive unit on the device body side and the driven drive unit on the cartridge side. However, the structure is complicated and large or expensive.

[0003]

As described above, according to the prior art, not only the apparatus becomes large, but also the image forming apparatus is expensive.

By the way, the environment surrounding the recent computers is accelerating the downsizing from the rise of small notebook type computers, and the market for personal use is expanded, so that the personal computers can be arranged with a margin on the table. As described above, there has been an increasing demand for miniaturization of external terminals such as printers and facsimiles corresponding to the miniaturization of computers and appearance of inexpensive products.

Therefore, the present invention solves the above problems, and an object thereof is to provide a simple structure with respect to the relationship between the driven gear and the driving gear that are disengaged when the cartridge is attached or detached. Thus, the cartridge can be easily attached and detached, the structure of the apparatus can be simplified, and a compact and inexpensive image forming apparatus can be developed. In particular, it meets the demand in the personal use market.

[0006]

The image forming apparatus of the present invention is an image forming apparatus in which a cartridge having a driven portion equipped with a driven gear and driven to rotate is detachable, and which engages with the driven gear. A second gear which is rotationally driven, a first gear which is drivingly transmitted to the second gear, a support means which rotatably supports the second gear and the first gear coaxially, and a coaxial core of the first gear and the second gear. Means for relatively rotating a predetermined angle with respect to each other, a rotation urging means for applying a predetermined torque to the first gear and the second gear to urge each other to rotate with respect to each other, and a mutual rotation with a predetermined torque. A first locking means that stops rotating in a biased state, and a first gear and a second gear abut against each other with the first gear or the second gear rotated against the rotation biasing means. And a second locking means that stops, and rotates the driven gear from the first gear through the second gear. When moving, the structure is such that the rotational drive is transmitted by the second locking means, and the first gear and the second gear are arranged at positions where the driven gear can be engaged and disengaged when the cartridge is disengaged. To do.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS.

1 to 13 show a suitable embodiment of the cartridge and the image forming apparatus of the present invention, and FIG. 1 is a sectional view of the left side principal part showing the whole of the image forming apparatus of the present invention. 3 is a sectional view of a front main part, FIG. 2 is a sectional view of a first front main part, and FIG. 3 is a sectional view of a second front main part, each of which shows a sectional view at a different position. , The left side from the alternate long and short dash line in the figure is omitted.

4 and 5 are cross-sectional views of the left side main part of the cartridge according to the present invention, and FIG. 4 is a cross-sectional view of the first left side main part,
FIG. 5 is a cross-sectional view of the main part of the second left side surface, and each drawing shows cross-sectional views at different positions.

FIGS. 6 and 7 are sectional views of the essential parts of the right side surface of the image forming apparatus of the present invention. FIG. 6 is a sectional view of the essential parts of the first right side surface.
FIG. 7 is a cross-sectional view of a first right side main part, and each drawing shows cross-sectional views at different positions.

FIG. 8, FIG. 9 and FIG. 10 are developed sectional views showing the rotary drive transmission portion of the image forming apparatus of the present invention. FIG. 8 is a first developed sectional view and FIG. 9 is a second developed sectional view. FIG. 10 is a third developed sectional view showing different rotary drive paths.

FIG. 11 is a sectional view of the principal part of the right side surface of the cartridge of the present invention, showing the rotational driven relationship.

FIG. 12 is a cross-sectional view of the main part of the upper surface of the cartridge of the present invention, in which the left side from the alternate long and short dash line is not shown.

FIG. 13 is an explanatory diagram relating to the rotational drive of the cartridge of the present invention.

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

The main part of the image forming means of this embodiment is shown in FIG.
The photosensitive drum 1, the charging roller 2, the cleaner portion 90, the developing portion 10, which are arranged in the substantially central portion as shown in the sectional view of the left side of FIG.
It is configured by the toner transport units 30 and 30a.

Referring to FIGS. 1, 4 and 5, the image forming process will be described in order. The charging roller 2 in this embodiment will be described.
Is formed of a semiconductive elastic body such as rubber, and is DC while being driven by the photosensitive drum 1 rotating in the direction of the arrow in the figure.
When a bias of about (−) 2 kv or less is applied, the photosensitive drum 1 can be charged to a charging potential of (−) 600V to (−) 700V.

The charging roller 2 is pressed and supported toward the photosensitive drum 1 by a pressing mechanism (not shown).
It is pressed against the photosensitive drum 1 with a total pressure of kg.

Next, the photosensitive drum 1 is image-exposed to form a latent image by the light beam emitted from the exposure device 40 which will be described later in detail and incident from the optical path 49, and the potential of the image exposure portion is (-). ) 50V to (-) 150V.

Next, in the developing section 10, the supply roller 13 formed of a semi-conductive elastic body such as foamed rubber and rotating in the direction of the arrow in the drawing is a toner which can be charged to the same polarity as the above-mentioned charging potential. The toner in the storage unit 11 for storing the toner is coated on the surface thereof and rotated, and is rubbed against the developing sleeve 12 formed of a semiconductive elastic body such as a rubber material which rotates in the direction of the arrow in the figure to rub the toner. Is triboelectrically charged to the negative polarity, and the surface of the developing sleeve 12 is coated with toner.

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

The developing sleeve 12 has a DC (-) 20
A bias of about 0 V to (-) 300 V is applied, and the thinned toner layer is conveyed to the photosensitive drum 1 and is formed in and near the nip portion formed by the developing sleeve 12 and the photosensitive drum 1 being in pressure contact with each other. Reversal development is performed on the image exposure unit of the photosensitive drum 1.

By the way, the toner in the storage unit 11 is as shown in FIG.
As shown in detail in the first left side sectional view of the cartridge, the cartridge upper case 17, the cartridge lower case 18, the regulating blade 14, the pressing member 16 of the regulating blade 14, the developing sleeve 12 and The space surrounded by the supply roller 13 is stored in a narrow predetermined space defined by a seal 15 having elasticity and formed of, for example, a foam rubber material.

Next, the toner image reverse-developed on the image exposure portion of the photosensitive drum 1 is transferred by the transfer portion 80, which will be described in detail later. The residual toner after transfer is, for example, a thin plate material such as mylar sheet material. The formed scooping sheet 91 slides through and is scraped off by the cleaning blade 92 that is in pressure contact with the photosensitive drum 1, and is stored in a predetermined space 93 formed by the scooping sheet 91 and the cleaning blade 92.

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

Here, the handling of toner will be described. In the conventional image forming apparatus, a predetermined amount of toner corresponding to the operating life of the main components such as the photoconductor is mounted as a cartridge enclosed in a casing of an integrated structure, which not only enlarges the entire apparatus but also replaces it. Although the image forming apparatus is expensive although the workability of maintenance is enhanced, the present embodiment has a configuration completely different from the conventional concept.

First, the amount of toner in the storage unit 11 is limited to a necessary minimum storage amount that does not hinder the image forming process, and the space space of the storage unit 11 is reduced. Then, the toner that decreases with the development is dropped and replenished from the toner transport unit 30a that transports the toner described later in the space of the storage unit 11.

On the other hand, the toner scraped off by the cleaning blade 92 is stored in a predetermined space 93 formed by the scooping sheet 91 and the cleaning blade 92, and the toner conveying portion 3 is increased as the storage amount increases.
Transition to 0.

Toners including endless coil springs 31 and 31a (which are endless and integrated, although they are described later in detail) are included in the toner conveying portions 30 and 30a. The toner transporting units 30 and 30a are provided with a mechanism for transporting toner by a transporting unit, and are disposed substantially horizontally and horizontally with the photosensitive drum 1 in the middle in the drawing. The toners of the toner conveying unit 30 and the toner conveying unit 30a which are connected to each other are circulated and conveyed.

Next, the toner circulation function will be described. With respect to the toner amount (developing toner amount) in the storage unit 11 consumed by the above-described development, the transfer residual toner amount scraped by the cleaning blade 92 and transferred to the toner conveying unit 30 (reproduced toner amount). In the present embodiment, the relationship is 10% to 30%. Even if the toner is circulated and conveyed as described above, the toner is consumed by the repeated development, and the toner is stored in the storage unit 11. Toner will decrease.

Therefore, in the present embodiment, in order to make up for this reduced toner, a toner replenishing means for dropping by its own weight is arranged in the transport path for circulating the toner, which will be described in detail later, and the reduced amount Toner is replenished and circulated and conveyed together with the above-mentioned recycled toner, and the toner is conveyed from the toner conveying section 30a to the storage section
It is configured to be dropped and replenished to 1.

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

The supply roller 13 formed of a semi-conductive elastic body such as foamed rubber and the developing sleeve 12 formed of a semi-conductive elastic body such as a rubber material are each made of a metal as a core metal. 2 is provided with supporting portions 12a and 13a extending to both ends of the elastic body. The supporting portions 12a and 13a are rotatably supported by the supporting member 5 as shown in FIG. Has been done. Although the supply roller 13 and the developing sleeve 12 are shown supporting the right side in the figure, the other side has the same supporting structure and is rotatably supported by the supporting member 5A.

Incidentally, the supply roller 13 and the developing sleeve 1
Regarding the support pitch of No. 2, the supply roller 13 and the developing sleeve 12 are supported at a fixed pitch narrower than the contact pitch between the outer circumferences of the supply roller 13 and the developing sleeve 12, and the outer circumferences of both rollers are evenly contacted over the entire area in the longitudinal direction. The positional relationship is shown in detail in FIG.

Then, the supply roller 13 and the developing sleeve 1
Reference numeral 2 denotes a configuration in which each roller is rotatively driven in the direction of the arrow to rub against each other. If the support pitch is extremely narrowed, the rotational driving torque increases, and the toner rubbed between both roller nips is increased. Since the deterioration becomes severe, in consideration of the absorption of the dispersion of the constituent members related to this support, in this embodiment, the supply roller 13 and the developing sleeve 12 are supported at a fixed pitch that is 0.2 mm narrower than the pitch at which the outer circumferences of the supply roller 13 and the developing sleeve 12 are in contact with each other.

A supporting member 5 and a supporting member 5A that rotatably support both ends of the supply roller 13 and the developing sleeve 12, respectively.
Are integrally connected by a fixing member such as a screw via a connecting member 6 to form an integral structure. As shown in FIG. 12, the supporting member 5 is a supporting pin 7 which is inserted into a part of the lower cartridge case 18. 12 is rotatably supported, and FIG. 12 shows a state in which only one side is supported, but the other side has a similar support structure, and the support member 5A is a support pin 7A which is inserted into a part of the cartridge lower case 18. It is rotatably supported by.

Then, the supply roller 13 and the developing sleeve 1
Both ends of 2 are rotatably supported and connected by the connecting member 6 together with the above-mentioned regulating blade 14 with the support pin 7 and the support pin 7A as a pivot so as not to interfere with the above-mentioned image forming process. The photosensitive drum 1 is placed in the space of the toner storage unit 11 configured to have the minimum storage amount.
It is possible to rotate integrally with respect to.

It should be noted that, when the support pins 7 and 7A are arranged at the positions shown in FIGS. 4 and 5, the lower cartridge case 18 and the support members are arranged so that the support pins 7 and 7A can be easily rotated by the above-mentioned integral structure. 5 and the supporting member 5A have a gap so as to be free in the rotational direction, and this gap is shielded by a sealing member having elasticity (not shown) to prevent toner leakage.

On the other hand, in the above state, the developing sleeve 12 and the photosensitive drum 1 are brought into pressure contact with each other to form a stable nip portion.
Also provided are springs 8 and 8A that set the hook portions at both ends to the cartridge lower case 18 and apply the tension to the supporting member 5 and the supporting member 5A to urge the developing sleeve 12 toward the photosensitive drum 1.

By the way, regarding the support structure of the support member 5 and the support member 5A by the support pin 7 and the support pin 7A described above, in the present embodiment, as a means for preventing the rotational failure even if the left and right support positions are misaligned. , The cartridge lower case 18 and the support pin 7 of the support member 5 at one support portion
The insertion part through which the support pin 7A is inserted is formed in a circular shape similar to the support pin 7, and the other support part is the insertion part through which the cartridge lower case 18 and the support pin 7A of the support member 5A are inserted. An oval opening 18b that can be moved toward and away from is formed to prevent the occurrence of the rotation failure of the above configuration.

The oval-shaped opening 18b is formed in the lower cartridge case 18 in the present embodiment. Conversely, the lower cartridge case 18 is changed into a circular opening, and the opening on the side of the supporting member 5A is formed into an oval shape. They may be formed, or even if both openings are formed in an oval shape, the rotation failure of the above configuration is prevented.

Now, the toner replenishing means and the toner conveying means for circulating and conveying 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 springs 31 and 31a for circulating and conveying the toner are provided on the cartridge upper case 17 and the cartridge lower case 18.
The toner tank 20 is configured so that it can be freely attached and detached (the attachment / detachment mechanism is not shown in the drawings), and a predetermined amount of toner is enclosed in the toner tank 20. The toner is replenished, and when this toner is consumed, it is replaced with a new toner tank 20.

The endless coil springs 31 and 31a which circulate and convey the toner are endlessly integrated, though the reference numerals are different for convenience of explanation in the drawing.
Although the left side is omitted from the one-dot chain line, it is configured endlessly.

The main portion of the toner tank 20 is a cylindrical tank case 21 having a bottom portion in the lower part of the figure, a cover 22 fixed to the upper portion to seal the toner, and the tank case 21 and the cover 22. A plurality of blades 23 that are sealed together with the toner to stir the rotatable toner
and a plurality of agitators 23 each having b, and endless coil springs 31 and 31a that circulate and convey toner are enclosed and detached by the upper cartridge case 17 and the lower cartridge case 18 (removable mechanism). Is a detailed description omitted in the drawing).

On the other hand, in order to drive the endless coil springs 31 and 31a which circulate and convey the toner in the direction of the arrow in FIG. 12, an endless coil enclosed by a cartridge upper case 17 and a cartridge lower case 18 so as to be circulatively movable. The drive means 25 of the coil springs 31 and 31a is arranged in a part of the arrangement path of the springs 31 and 31a, and the protruding portion 25a having a wedge-shaped protruding end is formed in a part of the driving means 25a.
7 and the toner tank 20 is mounted at a predetermined position, the wedge-shaped rotatable convex portion 25a and the concave portion 23c formed at one end of the one agitator 23 engage with each other to rotate and drive. To be done.

As the driving means 25 for the endless coil springs 31 and 31a that circulates and conveys the toner, any rotating body that can engage with the coil springs 31 and 31a can be driven, but in the present embodiment, the coil springs are used. A helical gear having a twist angle close to the lead angle of the stretched state of 31, 31a is employed to stabilize the engagement relationship with the coil springs 31, 31a.

One agitator 2 driven by the above configuration
A gear portion 23a is formed on a part of the third agitator 23 and the other agitator 23, and the gear portion 23a is rotationally connected by an idle gear 24.

The toner agitated by the rotation of the agitator 23 is circulated and conveyed through the opening 21a formed at the bottom of the tank case 21 and the opening 17a of the cartridge upper case 17 provided opposite to the opening 21a. Endless coil springs 31 and 31a
Is configured to drop by itself in the toner circulating and conveying path, and the opening 2 is interlocked with the attachment / detachment of the toner tank 20.
The opening 1a and the opening 17a are opened and closed. (Not shown) The toner dropped by its own weight in the toner circulation conveyance path in which the coil springs 31 and 31a are arranged is circulated and conveyed in the direction of the arrow in FIG.
When it shifts to 0a, it falls by its own weight from the upper portion of the supply roller 13 and is stored in the toner storage portion 11 described above with reference to FIG. 4. However, as described above, the toner storage portion 11 is extremely narrow, Due to the relationship between the consumption amount and the supply amount of toner, which varies depending on the image form, the toner storage unit 11 may become full. In this state, the toner is circulated and conveyed by the coil springs 31 and 31a without falling by its own weight. The toner drop from the toner tank 20 is also suspended.

The above is the main part of the image forming means of this embodiment, in which the photosensitive drum 1, the charging roller 2, the cleaner section 90, the developing section 10, and the toner conveying sections 30 and 30a are arranged in the above-mentioned relationship. A cartridge lower case 18 mainly responsible for the main part and a cartridge upper case 17 also responsible for the cover thereof are detachable from the main body as a cartridge having these as a unit structure, and are integrated during maintenance of the above structure part. It is configured to be removed and repaired or replaced.

Regarding the relationship between the cartridge and the main body, as shown in detail in part of FIG. 11, on the other hand, a concave portion is formed in the lower cartridge case 18 as a positioned portion to be positioned on the basis thereof. , The main chassis 10 that serves as a reference for the internal configuration of the device in this recess.
The convex portion 100a as a positioning portion formed in 0 is engaged to perform predetermined positioning in the height direction and the in-plane direction,
On the other hand, similarly, a part of the main chassis 100 is positioned in a predetermined direction in the height direction, and is fixed to the main chassis 100 by fixing means (not shown).

The main construction of the main chassis 100 is a sheet metal structure in this embodiment as shown in FIGS. 1, 3 and 12. First, in FIG. 1, the mother surface of the sheet metal construction is shown. With reference to the first surface 100c that positions and holds the unitized exposure device 40, which will be described in detail later, the first surface 100c is bent into an L-letter shape, and the unitized fixing unit 60 described in detail below is used. Unitized paper feed unit 70
And a second surface 100d for positioning and holding the transfer portion 80 are formed, and then the first surface 10d shown in FIGS.
The right and left ends orthogonal to the second surface 100d of
The third surface 100e is formed by bending the same in the same direction as 0d and positions and holds the cartridge (the left side is omitted from the alternate long and short dash line in FIGS. 3 and 12 but the same structure as the right side is formed and the third surface 100e is formed). It is a sheet metal integrated structure.

Then, the first surface 100c and the second surface 10
0d and the third surface 100e are positioned relative to each other and an opening is formed in a part of the third surface 100e in order to increase rigidity, and a convex portion engageable with the opening in a part of the second surface 100d. Is formed, and the third surface 100e is configured to have a coupling portion 100f that fits in the process of bending the third surface 100e. The first surface 100c, the second surface 100d, and the third surface 100e.
The mutual relation between the and
It is also highly rigid due to the effect of 0f.

Regarding the connecting portion 100f, it is effective to simply fit the two together, but in this embodiment, in order to further increase the stability, the connecting portion 100f is subjected to caulking fastening treatment. There is.

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.

The main part of the transfer 80 of this embodiment is pressed toward the photosensitive drum 1 from below by a pressing mechanism (not shown) with a total pressure of several 100 g, and is inverted into a latent image in the image exposure part of the photosensitive drum 1. D having the opposite polarity to the developed toner image
A means for applying a bias of around C1KV is provided,
For example, a rotatable transfer roller 81 formed of a conductive or semi-conductive elastic body such as rubber and a main constituent member of the sheet material conveying unit 70, which will be described in detail later, together with the transfer roller 8
The sheet material conveying base 71 supporting the sheet No. 1 is positioned at a predetermined position by engaging the positioned portion 71a with the positioning portion formed on the main chassis 100, which serves as a reference for the internal configuration of the apparatus. And is fixed to the main chassis 100 by a fixing means such as a screw.

The toner image conveyed to the nip portion formed by the pressing action of the photosensitive drum 1 and the transfer roller 81 forms a sheet material fed from the sheet material conveying portion 70, which will be described later, in the nip portion. It is merged and transferred.

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

The main part of the fixing unit 60 of the present embodiment is arranged on the downstream side in the sheet material conveying direction and has a heating element such as a halogen heater as a heat generating means incorporated in the hollow portion of the aluminum pipe material so as to be rotatable. 63 and a pressing mechanism composed of a lever 66 which is pressed by a pressing member such as a spring and is displaceable as pressing means for pressing the toner image transferred onto the sheet material onto the sheet material by several Kg toward the fixing roller 63. A pressure roller 67, which is pressed by the total pressure, is formed on at least the surface of a semiconductive elastic body such as silicon rubber, and is rotatable at the same peripheral speed as the fixing roller 63, is provided. In order to release the pressing force of the mechanism, an operation lever 6 that can be rotated from a position shown by a solid line in FIG. 1 and a position shown by a chain double-dashed line in FIG.
1, a cam 69 that is interlocked with the rotation of the operation lever 68 to move in the direction of the arrow in FIG. 1 to control the displacement of the lever 66, and a pair of discharge rollers 6 that discharges the conveyed sheet material to the outside of the apparatus.
1 and a fixing base 64 that supports the above-mentioned structural members and bears the fixing portion 60 in a unit structure. The fixing base 64 is a member for a positioning portion formed on the main chassis 100 that serves as a reference for the internal structure of the apparatus. It is positioned at a predetermined position by the engagement of the positioning portion 64a, and is fixed to the main chassis 100 by a fixing means such as a screw.

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

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

A sheet feed tray 72, which accommodates a large number of sheet materials P such as paper and is arranged at the rear of the apparatus, feeds the sheet material P at the lower end thereof with a high friction resistance material such as rubber. Part 7
A well-known pressing mechanism 74 that selectively presses the rotatable sheet feeding roller 73 of 0 is provided and is detachably supported on the apparatus main body.

The sheet feeding section 70 on the main body side of the apparatus is disposed so as to face the sheet feeding roller 73 with the sheet material P interposed therebetween, and only the uppermost one sheet material from the plurality of sheet materials P is fed by the sheet feeding roller. A sheet material feeding control mechanism 75 for preventing the sheet material from being separated by the rotation of 73 and the sheet material after the second sheet from being fed, and the sheet material feeding base 71 are opposed to the sheet material feeding base 71. A sheet material guide 76 arranged to form a sheet material conveying path, a sheet material detecting means 77 arranged in the sheet material conveying path and including a photosensor for detecting the presence or absence of the sheet material, and the sheet material conveying The operation lever 6 is composed of a sheet material conveying base 71 that supports the transfer roller 81 described above together with the main constituent mechanism of the section 70, and is further operable from the front surface of the fixing section 60, which is not shown. Is connected to a pressing force releasing mechanism interlocked with the operation of, for example, an operating means such as a link mechanism, and a mechanism for releasing the pressing of the transfer roller 81 against the photosensitive drum 1 in association with the operation of the operating lever 68 is also provided. The unit 70 and the transfer unit 80 are carried by the sheet material conveying base 71 as a unit structure, and as described above, the sheet material conveying base 71 covers the positioning portion formed on the main chassis 100, which serves as a reference for the internal structure of the apparatus. The main chassis 1 is positioned at a predetermined position by the engagement of the positioning portion 71a and is fixed by a fixing means such as a screw.
It is fixed at 00.

When the paper feed roller 73 is driven to rotate in the above-described structure, one sheet of material follows the sheet material conveying path and is fed to the transfer section 80 described above.

Here, the feeding control of the sheet material will be described. The sheet feeding roller 73 is rotationally driven by a desired command to feed one sheet of material into the sheet material conveying path, and the sheet feeding roller 73 is responsive to the detection signal of the sheet material detecting unit 77.
The sheet material is sandwiched and stopped to stand by for the above-mentioned transfer.

The stop timing of the paper feed roller 73 may be stopped by a detection signal of the sheet material detection means 77, but after a predetermined time elapses from this detection signal by a delay means such as a timer, the paper feed roller 73 is stopped and stands by. May be.

That is, the toner image reverse-developed on the image exposing portion of the photosensitive drum 1 at the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 is transferred to the photosensitive drum 1 by the rotation of the photosensitive drum 1. It is possible to control the time required for the roller 81 to reach the transfer portion 80, which forms the nip portion formed by pressure contact, and the time for the sheet material to be fed from the standby state to reach the transfer portion 80, in a desired relationship. The latter is adopted in this embodiment.

By the way, in the present embodiment, the sheet material detecting means 77 including a photo sensor for detecting the presence or absence of the sheet material is arranged in the sheet material conveying path of the sheet feeding section 70, and the other one is not shown. However, a second sheet material detecting means similar to the downstream side in the sheet material conveyance direction from the nip portion formed by the pressing action of the fixing roller 63 and the pressure roller 67 of the fixing unit 60 is provided, and the sheet material conveyance state is determined. The jam condition in the apparatus is monitored by detecting and processing the detection signals from the sheet material detecting means 77 and the second sheet material detecting means in a predetermined relationship.

The image forming apparatus according to the present embodiment has a compact structure, and the paper feeding unit 70 is used for jam processing.
If the jammed side is the side, the sheet material is pulled out to the rear of the apparatus, and if the jammed state is on the fixing unit 60 side, the pressing force of the pressure roller 67 against the fixing roller 63 is operated by operating the operation lever 68 that can be operated from the front side of the apparatus. Also, the pressing of the transfer roller 81 against the photosensitive drum 1 is released, and the sheet material is pulled out toward the front of the apparatus so that it can be processed.

Next, the exposure device 40 for exposing the photosensitive drum 1 to a latent image will be described. The main part of the exposure device 40 is a motor 41 that rotates at 10,000 rpm, a control circuit board (not shown) that controls the rotation of the motor 41, and the motor 41.
A deflection scanning means 43 which is mounted on the output shaft of the optical disc 1 and rotates to deflect and scan a light beam emitted from a light emitting element such as a semiconductor laser (not shown); and an optical path 49 for irradiating the light beam toward the photosensitive drum 1. A reflection mirror 44 and the like to be formed,
The exposure unit case 42 is configured by accommodating the above-mentioned main constituent members into a unit, and the exposure unit case 42 is related to the positioned portion 42a with respect to the positioning portion formed on the main chassis 100 which serves as a reference for the internal configuration of the apparatus. Depending on the combination, they are positioned at a predetermined position, and are fixed to the main chassis 100 by fixing means such as screws.

Regarding the deflection scanning means 43, Japanese Patent Application No. 5-121995 filed previously by the present applicant.
As described in detail in the above, the optical scanning is small and inexpensive, and in this embodiment, the optical path length from the deflection scanning means 43 to the photosensitive drum 1 is set to about 200 mm, but about 140 mm. It is also possible to correspond to the short optical path length.

Next, the control section 50 which controls the above-mentioned respective mechanical sections will be described. The main part of the control unit 50 is arranged at the lowermost end of the device, and at least the power supply circuit unit and the operation control circuit unit of each mechanism unit are arranged, and although not shown, an interface connector and a power supply for receiving a signal from the outside. Connected to input / output connection means such as input connector,
The control unit 50 is compactly and centrally deployed.

From here, the drive relationship of the above-mentioned respective structural parts will be described with reference to FIGS. 2 and 3, 6 and 7, FIG. 8, FIG. 9, FIG. 10, FIG. 11, FIG. 12 and FIG. To do.

The main portion of the drive transmission portion of this embodiment is centrally arranged on the right side surface of the main chassis 100, that is, the third surface 100e, and the first train wheel train receiver 101 and the second train wheel train receiver 1 are arranged.
02 are provided in opposition to each other, and a drive motor 103 having a drive gear 103a on an output shaft and a plurality of drive gear trains described in detail later are rotatably supported by these two train wheel receivers to form a unit structure. Main chassis 100 that is the basis of the configuration
It is positioned at a predetermined position by the engagement of the positioned portion with the positioning portion formed on the third surface 100e, and is fixed by a fixing means such as screw tightening.

In this embodiment, the train wheel first receiver 101 and the train wheel second receiver 102 have a sheet metal construction, and as will be described later in detail, there is provided means for inexpensively constructing the characteristics. Is a feature.

The entire drive system of this embodiment will be described with reference to FIGS. 6 and 7. 6 and 7 are cross-sectional views of a right side main part showing a suitable embodiment of a drive system used in the image forming apparatus of the present invention. The wheel train first receiver 101 and the wheel train second receiver 102 are shown in the drawing. For the sake of clarity, FIG. 7 omits these two train wheel receivers to make it easier to see each gear train. 6 and 7, the rotation center position of each gear is marked with + in the figure. (The same applies to FIGS. 11 and 13) First, referring to FIG. 7, regarding the drive system of the present embodiment, the drive gear 103 provided on the output shaft of the drive motor 103 is provided.
A description will be given for each individual drive system starting from the common A # gear driven by a.

<First Drive System> The first drive system for rotationally driving the photosensitive drum 1 is A # gear → J # gear → K #.
The L # gear is driven in the order of gears → L # gear, and the L # gear is a gear fixed to one end of the photosensitive drum 1 by a fixing means such as an adhesive. , Connect to or disconnect from this first drive system.

The attachment / detachment of the cartridge of this embodiment is performed by moving the cartridge in the vertical direction in the figure.

<Second Drive System> The second drive system for rotationally driving the developing sleeve 12 which is the main constituent member of the developing unit 10 is A # gear → B # gear → C # gear → F # gear →
The G # gear is driven in this order, and the G # gear is a gear fixed to the projecting end of the supporting portion 12a extending to the one end side of the developing sleeve 12 by a fixing means such as press-fitting. , Is connected to or disconnected from this second drive system.

<Third Drive System> The third drive system for rotationally driving the supply roller 13 which is the main constituent member of the developing unit 10 is A # gear → B # gear → C # gear → D # gear → E.
The # # gear is driven in this order, and the E # gear is the supply roller 1 described above.
3 is a gear fixed to a projecting end of a support portion 13a extending to one end side of 3 by fixing means such as press-fitting, and is connected to or disconnected from the third drive system by attachment / detachment of the cartridge described above.

<Fourth Drive System> The drive means 25 for driving the endless coil springs 31 and 31a for circulating and conveying the toner and the agitator 2 of the toner tank 20 are described.
The fourth drive system that rotationally drives 3 is driven in the order of A # gear → B # gear → C # gear → F # gear → H # gear → V # gear (V # gear is shown in FIG. 6), and V The # gear is a helical gear fixed to one end side of the driving means 25 by a fixing means such as press fitting, and the H # gear for driving the # gear is a helical gear rotatably supported by the cartridge lower case 18. Then, the H # gear is connected to or disconnected from the fourth drive system by the attachment / detachment of the cartridge described above.

<Fifth Drive System> The fifth drive system for rotationally driving the paper feed roller 73 is A # gear → B # gear → M.
The gears are driven in the order of # gear → N # gear, and the N # gear is a gear mounted on the clutch disposed on one end side of the above-described paper feed roller 73, and is always connected to the fifth drive system.

<Sixth Drive System> The sixth drive system for rotationally driving the fixing roller 63 is A # gear → P # gear → Q.
The ## gear and the #R gear are driven in this order. The R # gear is a gear mounted on one end side of the fixing roller 63 described above, and is always connected to the sixth drive system.

<Seventh driving system> The pair of paper discharge rollers 61 described above.
The 7th drive system that drives to rotate is A # gear → P # gear →
The S # gear, the T # gear, and the U # gear are driven in this order. The U # gear is a gear mounted on one end side 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 of the present embodiment, each main part is dispersedly driven while avoiding the one-dimensional concentration of the rotational drive force.

Next, a detailed description will be given of the main part of each drive system.

<First drive system> A # gear → J # gear → K
The first drive system for rotationally driving the photosensitive drum 1 driven in the order of # gear → L # gear has a structure shown in detail in FIGS. 8 and 11, and FIG. 8 is an exploded sectional view showing this first drive system. There is.

The drive gear 103a provided on the output shaft of the drive motor 103 mounted on the first train wheel receiver 101 is formed on each of the first train wheel receiver 101 and the second train wheel receiver 102 with its inner surface being a mirror surface. Burring parts 101a and 10
Drive the A # gear rotatably supported by 2a,
Further, the first train wheel provided to face the second train wheel receiver 102.
The K # gear is driven via the J # gear that is rotatably supported by the push Ja that is press-fitted and held in the projection unit 101b of the receiver 101 to reach the L # gear.

As described above, since the L # gear is connected to or detached from this drive system by attaching or detaching the cartridge, in the present embodiment, the engaging relationship between the K # gear and the L # gear is facilitated at the time of attaching or detaching. As a means, K
The # gear has a double structure of a K1 # gear and a K2 # gear, and one K1 # gear has the same train wheel first receiving member 101 as the A # gear.
Burring portion 101c formed on the inner surface with a mirror surface
Therefore, the other K2 # gear is rotatably supported, and one end of the K2 # gear is supported by the projection portion 102b of the second train wheel receiver 102, which is provided with one end facing the first train wheel receiver 101 and the outer peripheral portion of which is mirror-finished. The other end of the K2 # gear is rotatably supported by being inserted into the K1 # gear. The K1 # gear and the K2 # gear are integrally rotatable, and K1 # in the drawing is used. As shown in the sectional view of the double structure of the gear and the K2 # gear as viewed from A, one K1 # gear is formed with a concave portion K1 # a and a convex portion K1 # b at point-symmetrical positions.
The other K2 # gear, in which the concave portion K2 # a and the convex portion K2 # b are formed in point symmetry in #a, is inserted to be relatively rotatable with respect to each other by a predetermined angle. The compression springs KS are arranged in the concave portions K1 # a and K2 # a of each of the convex portions K1 # b and K2 #.
b is abutted and the stopped state is maintained (A cross section 1),
The structure is such that the K2 # gear and the L # gear mesh with each other.

Then, when the K1 # gear is rotationally driven in the direction of the arrow in the figure, as shown in the cross-section 2 when viewed from A, the K2 # gear which meshes with the L # gear and has a rotational load is stopped within a short time. The compression spring KS is compressed, and only the K1 # gear rotates, so that the second convex portion K1 # c formed at the point symmetrical position of the K1 # gear and the second convex portion K2 formed at the point symmetrical position of the K2 # gear. The #c is brought into contact with the K2 # gear to rotate in the arrow direction in the figure to drive the L # gear in the arrow direction in FIG.

In the above structure, when the L # gear is driven in the direction of the arrow in FIG. 11 and then rotationally stopped and the cartridge is taken out upward in FIG. 11, the L # gear and the K2 # gear are disengaged from each other. Since it is arranged at a position where it is possible, the meshing is released without difficulty and the rotational drive load of the K2 # gear is released, and the compression spring KS is extended to move the K2 # gear to the position shown in FIG.
Rotate in the direction of the arrow of the middle A-view cross section 2 to move to the above A-view cross section 1
On the other hand, when the cartridge is mounted from the upper side in FIG. 11 in the state of A cross section 1 as viewed from A in FIG. 11, the photosensitive drum 1 and the developing sleeve 12 described above are in the process of the L # gear and the K2 # gear meshing with each other. The L # gear causes the K2 # gear to rotate in the opposite direction of the normal rotation direction, that is, the K2 # gear of FIG. The structure is such that it is mounted by rotating it counterclockwise by a predetermined angle, and even if the K2 # gear is rotated counterclockwise by a predetermined angle, the state up to the cross-sectional view 2 in FIG. The second convex portion K1 #
The relationship between c and the second convex portion K2 # c is configured.

The drive motor 103 of this embodiment is
An inexpensive PM type stepping motor is used, and smooth continuous rotation drive is possible by controlling the input pulse and current.

<Second drive system> A # gear → B # gear → C
Developing unit 1 driven in the order of # gear → F # gear → G # gear
The second drive system for rotationally driving the developing sleeve 12, which is the main component of No. 0, has a structure shown in detail in FIGS. 9, 10 and 11, and FIG. 9 and FIG. Illustrated.

The relationship between the first train wheel train receiver 101, the drive motor 103, the first train wheel train train receiver 101, the second train wheel train train receiver 102, and the A # gear is the same as that of the second drive system. # The drive from the gear forward will be described.

The A # gear is a pair of B # gears that are rotatably supported by push Bas that are press-fitted and held by a burring portion 102c provided on the second train wheel bridge receiving member 102. Further, the F # gear is driven (FIG. 10) and the rotational drive thereof reaches the G # gear. The C # gear of FIG. 9 and the C # gear of FIG. 10 are the same here.

The pair of B # gears is composed of a B1 # gear and a B2 # gear, and the B1 # gear and the B2 # gear are connected by press fitting of an oval type engaging portion and an engaged portion indicated by B in the drawing. It can rotate as a unit.

The C # gear of the next-stage wheel train has a third gear which will be described later.
It also has a rotary drive transmission branch function to the drive system.
Driven by gears.

The main part of the C # gear is the second train wheel support 102.
Burring portion 102d formed by mirroring the inner surface
A tumbler arm C1 having a bearing function rotatably supported by a tumbler function and a tumbler function described later in detail, and a tumbler arm C1 which is inserted through the tumbler arm C1 and the other end of which is formed into a train wheel first receiver 101 with its inner surface being a mirror surface. The main shaft C2 rotatably supported by the burring portion 101d and the flange portions of the tumbler arm C1 and the main shaft C2 are guided in the thrust direction, and are rotated on the basis of the main shaft C2 and the double structure described later in detail. The main shaft C2 is driven by the free C2 # gear and the oval-shaped engaging portion and the engaged portion which are driven by the B2 # gear and press-fitted into the engaged portion.
It is constituted by a C1 # gear which is coupled with and is rotatable integrally. The G # gear is rotationally driven from the C2 # gear through the F # gear.

The F # gear has a double structure of the F1 # gear and the F2 # gear. Like the K # gear of the first drive system described above, one of the F2 # gears has the inner surface on the first train wheel train receiver 101. It is rotatably supported by a burring portion 101e formed in a mirror surface state, and the other F1 # gear has one end having a train wheel first receiving member 1e.
No. 01, and the projection portion 102e of the second train wheel bridge receiver 102, which is formed to have a mirror-like outer peripheral portion.
And the other end of the F1 # gear is inserted into the F2 # gear and rotatably supported. 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.) Here, as described above, the G # gear is connected to or detached from the F1 # gear of the second drive system by attaching or detaching the cartridge. Therefore, in this embodiment, F1 is attached and detached in this embodiment.
As a means for facilitating the meshing relationship between the # gear and the G # gear, a mechanism for performing the same action on the C # gear as the K # gear of the first drive system is configured.

That is, in FIG. 10, C2 # gear and main shaft C2 2
As shown in the BB cross-section of the double structure part of the heavy structure and the F1 # gear and the F2 # gear, the recess C is formed in one of the C2 # gears.
2 # a and the convex portion C2 # b are formed at the point symmetric positions, and the other main shaft C2 having the concave portion C2a and the convex portion C2b formed at the point symmetric positions is inserted into the concave portion C2 # a and inserted into each other at predetermined positions Of the compression spring CS, which is relatively rotatable by the angle C2 # a and C2a.
Are arranged and are urged to rotate in one direction with respect to each other, so that the convex portions C of both sides are
The 2 # b and C2b are in contact with each other to maintain the stopped state (BB cross section 1), and the C2 # gear and the F1 # gear mesh with each other.

When the main shaft C2 is rotationally driven from the C1 # gear in the direction of the arrow in the figure, as shown in the BB cross section 2, the C2 # meshes with the F1 # gear and has a rotational load within a short period of time. While the gear is stopped, the compression spring CS is compressed and only the main shaft C2 rotates, and the second convex portion C2c formed at the point symmetrical position of the main shaft C2 and the second convex portion C2 formed at the point symmetrical position of the C2 # gear. The #c is brought into contact with the C2 # gear to rotate in the direction of the arrow in the figure to drive the F1 # gear.

In the above structure, when the main shaft C2 is driven in the direction of the arrow in FIG. 11 and then rotationally stopped and the cartridge is taken out upward in FIG. 11, the G # gear and the F1 # gear can be disengaged from each other. Since it is placed in a proper position, its meshing is released without difficulty and C2 # together with F1 # gear.
The rotational drive load of the gear is released, the compression spring CS expands, and the C2 # gear is rotated in the arrow direction of BB cross section 2 in FIG. 10 to reach the state of BB cross section 1 described above. When the cartridge is mounted from the upper side in FIG. 11 in the state of BB cross section 1, the photosensitive drum 1 and the developing sleeve 1 described above are in the process of the G # gear and the F1 # gear meshing with each other.
2 pressure contact relationship or developing sleeve 12 and regulating blade 1
4. Due to the rotational driving load generated by the pressure contact of the supply roller 13, the G # gear moves the C2 # gear through the F1 # gear in the direction opposite to the normal rotation direction, that is, the compression spring C.
11 is a structure in which the 2 # gear of FIG. 11 is rotated counterclockwise by a predetermined angle against the extension force of S, and C is mounted.
Even if the 2 # gear is rotated counterclockwise by a predetermined angle, the state of the second convex portion C2c and the second convex portion C2 # c does not reach the state of BB cross section 2 in FIG. The relationship is structured.

<Third drive system> A # gear → B # gear → C
Developing unit 1 driven in the order of # gear → D # gear → E # gear
The third drive system for rotationally driving the supply roller 13, which is the main constituent member of No. 0, has a structure shown in detail in FIGS. 9, 10 and 11, and FIGS. Illustrated.

With reference to FIGS. 9 and 10, the drive motor 10
Since the drive from 3 to C # gear is the same as the contents described in the second drive system, the description will be omitted, and the drive from the C # gear onward will be described.

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

A tumbler arm C1 having one end rotatably supported by a burring portion 102c formed by mirroring the inner surface of the second train wheel receiver 102 and having a bearing function and a tumbler function for the main shaft C2 is shown in FIG. As described above, the other end has a bearing portion C1a for rotatably supporting the D # gear, and the bearing portion C1a is inserted into the opening 102f formed in the second train wheel receiver 102 so as to be rotatable by both play gaps. It is regulated.

The bearing portion C of the tumbler arm C1
The D # gear rotatably supported by 1a is the above C
It is driven by the 1 # gear to drive the E # gear.

Here, C1 # gear and tumbler arm C1
The planetary drive mechanism including the D # gear and the D # gear will be described.

Referring to FIG. 11, in the planetary drive mechanism of the present embodiment, the C # gear (C1 # gear) is rotationally driven in the direction of the arrow in the figure to set the gear pressure at the meshing point of the C1 # gear and the D # gear. The tumbler arm C1 is rotationally biased in the rotational direction by the friction between the main shaft C2 and the tumbler arm C1 which are rotationally driven in the angular direction and the arrow direction in the figure, and the D # gear is With the planetary motion of rotating and revolving, the planetary structure moves toward the E # gear while approaching the E # gear.
In addition, the tumbler arm C1 can be operated without any means, and the tumbler arm C1 and the opening 102f formed in the second train wheel second receiver 102 and the bearing C
It has a structure in which the planet is urged to move by a play gap with respect to 1a and movement is restricted.

Based on this planetary drive mechanism, D # gear and E # gear
As a means for stabilizing the meshed state of the gears, in this embodiment, a first circumferential portion D # a coaxial with the gear portion is formed in a part of one D # gear, and a part of the other E # gear is similarly formed. Also, a second circumferential portion E # a coaxial with the gear portion is formed, and both are in contact with each other to be rotatable.
And the distance between the pitches of the second circumferential portion E # a in contact with each other is D #
It is related so that an appropriate backlash may occur when the gear and the E # gear mesh with each other.

Here, as described above, the E # gear is configured to be connected to or disconnected from the D # gear of this drive system by the attachment / detachment of the cartridge, and the attachment / detachment of the cartridge will be described.

The C # gear (C1 # gear) having the above structure is shown in FIG.
1 When the rotational drive is stopped after driving in the direction of the middle arrow, the D # gear and the tumbler arm C1 that have been urged to move the planet by the planet drive mechanism are released from the urging force and are in the free state. When the above-mentioned cartridge is taken out upward in FIG. 11, the D # gear moves in a direction away from the E # gear, and it is extremely easy to take out the cartridge.

On the other hand, this time, when the cartridge is mounted from above in FIG. 11 in the state after taking out the cartridge, the D # gear and the E # gear are in a state of meshing or having a play. C # gear (C1 # gear)
11 is driven in the direction of the arrow in FIG. 11, the D # gear moves in a direction approaching the E # gear while performing the planetary motion with or without the load of the E # gear, and both are moved. Gears mesh with each other.

If the cartridge is mounted from above in FIG. 11 while the D # gear is moving in the direction approaching the E # gear, the D # gear and the tumbler arm C1 will be described.
Is released from its urging force and is in a free state, the D # gear moves to a predetermined position while meshing with the E # gear.

Now, description will be given of a case where the D # gear meshes with the E # gear and a predetermined rotational load is generated in the E # gear, so that the E # gear is rotationally driven.

The larger the rotational load, the D #
As for the planetary movement biasing force against the gear, especially the planetary movement biasing force in the direction of the pressure angle of the gear at the meshing point of the C1 # gear and the D # gear becomes large, and the D # gear approaches the E # gear. However, the above-mentioned first circumferential portion D # a
The urging movement is restricted by the contact state of the second circumferential portion E # a, and the engagement between the D # gear and the E # gear is rotationally driven with an appropriate backlash.

<Fourth drive system> A # gear → B # gear → C
# Gear → F # Gear → H # Gear → V # Gear (shown in FIG. 6)
9 and 10 and 11, the fourth driving system for rotationally driving the agitator 23 of the toner tank 20 and the driving means 25 for driving the endless coil springs 31 and 31a which circulates and conveys the toner in this order will be described in detail. 9 and 10 are exploded sectional views of the first drive system.

With reference to FIGS. 9 and 10, the drive motor 10
Since the drive from 3 to F1 # gear is the same as that described in the second drive system, the description is omitted, and the drive from the F1 # gear onward is described.

As described above in the section of the second drive system, the F # gear has a double structure of the F1 # gear and the F2 # gear like the C # gear, and the F2 # gear constitutes the H # gear. It is configured to drive the V # gear.

Here, as described above, since the H # gear is connected to or disconnected from the F2 # gear of the fourth drive system by the attachment / detachment of the cartridge, in the present embodiment, the F2 # gear and the H # gear are attached or detached. As a means for facilitating the meshing relationship, a mechanism for performing the same action on the F # gear as the C # gear of the second drive system is configured.

That is, in FIG. 10, C2 # gear and main shaft C2 2
As shown in the BB cross-section of the double structure part of the heavy structure and the F1 # gear and the F2 # gear, the recess F is formed in one of the F1 # gears.
1 # a and the convex portion F1 # b are formed at the point symmetrical positions, and the other F2 # gear having the concave portion F2 # a and the convex portion F2 # b formed at the point symmetrical positions is inserted into the concave portion F1 # a. Are fitted so that they can rotate relative to each other by a predetermined angle, and
A compression spring FS, which is simplified in the drawing, is arranged in both concave portions F1 # a and F2 # a, and both convex portions F1 # b and F2 # b are brought into contact with each other so as to be in a stopped state. Is maintained (BB cross section 1), and the F2 # gear and the H # gear mesh with each other.

When the F1 # gear to the F2 # gear are rotationally driven in the direction of the arrow in the figure, as shown in the BB cross section 2, the F2 gear meshes with the V # gear within a short time and has a rotational load. While the # gear is stopped, the compression spring FS is compressed to rotate only the F1 # gear, and the second convex portion F1 # c formed at the point symmetrical position of the F1 # gear is formed at the point symmetrical position of the F2 # gear. The second convex portion F2 # c is brought into contact with the F2 # gear to rotate in the direction of the arrow in the drawing to drive the V # gear.

In the above structure, the F1 # gear is driven in the direction of the arrow in FIG. 11 and then rotationally stopped, and the above cartridge is taken out upward in FIG.
Since the gears are arranged at positions where they can be disengaged from each other, their meshing is disengaged without difficulty, the rotational drive load of the F2 # gear is released, and the compression spring FS extends to move the F2 # gear to the B- in FIG. Rotate in the direction of the arrow of B section 2 to
The state of B cross section 1 is reached. On the other hand, when the cartridge is mounted from above in FIG. 11 in the state of BB cross section 1,
In the process in which the F2 # gear and the H # gear are brought into the meshing state, the rotational driven load related to the driving means 25 for driving the endless coil springs 31 and 31a for circulating and transporting the toner described above, through the V # gear. H # gear is F
A structure opposite to the normal rotation direction of the 2 # gear, that is, a structure in which the F2 # gear of FIG. 11 is rotated counterclockwise by a predetermined angle against the extension force of the compression spring FS to be mounted. Therefore, even if the F2 # gear is rotated counterclockwise by a predetermined angle, the second convex portion F1 # c and the second convex portion F1 # c are formed so as not to reach the state of BB cross section 2 in FIG. The relationship of the part F2 # c is configured.

By the way, since the fourth drive system has the above-mentioned double structure of gears in series with the C # gear and the F # gear, when the cartridge is mounted, the H # gear and the F2 # gear are the G # gear. And the F1 # gear are engaged before the above operation is performed, the operation is performed in the configuration of the F # gear, and the independent operation that does not affect the meshing of the G # gear and the F1 # gear that are subsequently engaged. Therefore, the balance of the biasing torques of the respective gears biased by the compression spring CS and the compression spring FS is considered.

Next, the above-mentioned drive gear train is supported to form a unit structure, and the third surface 100e of the main chassis 100 is formed.
The relationship between the drive transmission part fixed to the cartridge and the driven part on the cartridge side will be described with reference to FIG.

In the present embodiment, in the relationship between the drive unit on the main body side and the driven unit on the cartridge side, the concentration of the driving force or the driven force is avoided, and neither of them needs to have a high rigidity structure. It has a decentralized structure so that it can be made compact and inexpensive, and its specific contents will be described first.

The working relationship of the forces of the drive unit on the main body side and the driven unit on the cartridge side is indicated by the direction of the pressure angle of the gear at the meshing point of the drive gear on the main body side and the driven gear on the cartridge side. It is as follows for each system.

<First Drive 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 pointing diagonally upward to the left in the figure.

<Second Drive System> The acting direction of the force for driving the G # gear from the F # gear is the direction of arrow G pointing diagonally upward to the right in the figure, and the L # gear is driven from the K2 # gear. The direction of the force acting arrow L is different from that in the direction of the angle αG, and the specific angle in this embodiment is approximately 95 deg.

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

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

As described above, in the present embodiment, the developing sleeve 12 which is the main part of the developing unit 10 is acted against the acting direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear.
And drive means 2 for driving the supply roller 13 and endless coil springs 31 and 31a that circulate and convey the toner.
5 and the force of driving the agitator 23 of the toner tank 20 to rotate are acting in different directions,
Further, the action positions of this force are dispersed, so that the driven portion on the cartridge side or the driving portion on the main body side does not have to have high rigidity.

The above is the relationship for each drive system constructed so as to avoid the concentration of the drive force on the main body side or the driven force on the cartridge side in this embodiment, while the drive force for each drive system When combined, the direction becomes an arrow T which is directed obliquely upward in the figure, and the direction of an angle αT is different from the action direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear.
Since the action direction arrow L and the action direction arrow T do not act in series, the fixing force can be reduced when fixing the cartridge.

The pressure angle direction of the gear at the meshing point of the drive gear on the main body side and the driven gear on the cartridge side varies by about ± 15 deg due to the attachment / detachment of the cartridge or the variation in the constitutional requirements. It should be taken into consideration that, in the configuration of the present embodiment, at least the driving force acting in the direction of the arrow T, which is substantially synthesized, is positive with respect to the action direction arrow L of the force for driving the photosensitive drum 1 from the K2 # gear. It is a structure in which the above effect is exerted when acting in different directions over a region parallel to the lines L1 and L2 shown in FIG.

On the other hand, now, let us focus on the structural relationship between the driving force acting on the developing sleeve 12 and the supply roller 13, which are the main parts of the developing unit 10, and the developing unit 10.

As described above with reference to FIGS. 4, 5 and 12, the supporting member 5 and the supporting member 5A, which rotatably support both ends of the supply roller 13 and the developing sleeve 12, which are the main parts of the developing unit 10, are connected. The support member 5 is integrally connected to the cartridge lower case 1 as shown in FIG. 12 by being firmly connected by a fixing means such as a screw via the member 6.
8 is rotatably supported by a support pin 7 which is inserted through a part of the support 8, and FIG. 12 shows a state in which only one side is supported, but the other side has the same support structure, and the support member 5A is a cartridge lower case. Support pin 7 that is inserted through a part of 18
It is rotatably supported by A, and is configured to be rotatable integrally with the photosensitive drum 1 with the support pin 7 and the support pin 7A as a spindle together with the above-mentioned restriction blade 14. Due to the action of the driving force acting in the direction of arrow G of the second drive system and the driving force acting in the direction of arrow E of the third drive system described above, the main part of the developing unit is centered around the support pin 7 in the drawing. It is urged to rotate and move in the direction of arrow 110, that is, in the direction in which the developing unit 10 separates from the photosensitive drum 1.

Therefore, in the above-mentioned structure of this embodiment, the nip width is stabilized without causing an excessive driving force due to the phenomenon of biting into both the photosensitive drum 1 and the developing sleeve 12 at the sliding nip portion. As described above, the driving action positions of the photosensitive drum 1 and the developing unit 10 are dispersed, and the driven portion on the cartridge side or the driving portion on the main body side does not have to be highly rigid. Since there is no load condition concentrated on the driven part on the cartridge side or the drive part on the main body side, vibration and chatter are suppressed, and driving with less rotation jitter is possible.

In this embodiment, as described above, both ends are set in the cartridge lower case 18 so that the developing sleeve 12 and the photosensitive drum 1 are in pressure contact with each other to form a stable nip portion, as described above. Further, since springs 8 and 8A for applying the tension to the supporting member 5A to urge the developing sleeve 12 toward the photosensitive drum 1 are also provided, the main portion of the developing unit has the supporting pin 7 as the supporting center as described above. In the structure shown in FIG. 1, a stable nip between the developing sleeve 12 and the photosensitive drum 1 is formed even when the developing sleeve 12 and the photosensitive drum 1 are rotated and biased in the direction of the arrow 110, that is, in the direction away from the photosensitive drum 1.

With respect to the present embodiment described above, the drive structure of the cartridge which should be noted here will be summarized as follows.

The system disengagement between the driven side and the driving side in this embodiment at the time of mounting / removing the cartridge is performed by the first driving system for driving the photosensitive drum 1 and the developing sleeve 12 which is a main constituent member of the developing section 10. A second drive system that rotates, and endless coil springs 31 and 3 that circulate and convey toner.
As described above in the fourth driving system that rotationally drives the agitator 23 of the toner tank 20 and the driving means 25 that drives 1a, each driven portion is provided with a driven gear, and by mounting or removing the cartridge, this driven gear As means for facilitating the meshing relationship between the drive gears arranged on the main body side, the drive gear has a double structure of a first gear and a second gear, and the first gear and the second gear are structured as described above. A gear meshed with the driven gear on one side of the first gear and the second gear, which is instructed by an instructing unit that coaxially and rotatably instructs the first gear and the second gear so that the first gear and the second gear can rotate relative to each other by a predetermined angle on the coaxial core. A concave portion and a convex portion are formed in the rotational direction of the first gear that is transmitted to the vehicle at point-symmetrical positions, and the concave portion and the convex portion are similarly formed in the rotational direction at the point-symmetrical position on the other side. Driven by A second gear that meshes with the gear is inserted and configured to be relatively rotatable with respect to each other by a predetermined angle, and a first torque is applied to the first gear and the second gear to urge them to rotate with respect to each other. A compression spring is arranged in a recess common to both as a rotation urging means that is rotated when a turning force is applied by a second torque in the opposite direction larger than one torque, and the compression spring is rotated by the first torque. The first that stops rotating in the energized state
As the locking means, a convex portion is arranged on each of the convex portions so as to maintain the initial state in which both convex portions are brought into contact with each other and stopped by being biased in one direction, and the first gear to the second gear are connected. When rotationally driven, the compression spring is compressed and only the first gear rotates while the second gear, which has a rotational load and meshes with the driven gear, is stopped within a short period of time, so that the second gear is rotated by the second torque. The second convex portion formed at the point symmetrical position of the first gear and the second convex portion formed at the point symmetrical position of the first gear arranged as the second locking means for stopping the first gear and the second gear in contact with each other in the stopped state. Done second
The convex portions are in contact with each other and the second gear is rotated to drive the driven gear, and the first gear is rotationally driven to drive the driven gear via the second gear and then the rotational drive is stopped. Then, when the cartridge is taken out, the meshing between the second gear and the driven gear, which are arranged at positions where they can be disengaged from each other, is easily disengaged, the rotational driving load of the second gear is released, and the compression spring expands. Then, the second gear is rotated to reach the initial state. On the other hand, when the cartridge is mounted in the initial state this time, the driven gear is driven by the rotational driven load while the second gear and the driven gear are in the meshing state. The gear has a structure in which the second gear is mounted by rotating the second gear by a predetermined angle in a direction opposite to the normal rotation direction of the second gear, that is, in a direction against the extension force of the compression spring. Very easy to put on and take off It is free, with respect to the gear and the drive side of the gear of the relationship in the driven side when the cartridge is detachable,
This embodiment does not have a complicated structure as disclosed in Japanese Patent Application Laid-Open No. 1-222270 and can be inexpensively configured with the simple structure as described above.

In this embodiment, the drive mechanism described above is used to drive the photosensitive drum 1, a first drive system, a second drive system for rotationally driving the developing sleeve 12, which is a main component of the developing section 10, and toner. A preferable example adopted in the fourth driving system for driving the driving means 25 for driving the endless coil springs 31 and 31a for circulating and conveying and the agitator 23 of the toner tank 20 is shown, but it is essential to adopt for all of them. This is not a condition, and it may be deleted in a department where the driving load on the driven side is light and may be configured by simply disengaging the gears.

Further, in the present embodiment, the detailed structure of the drive-side gear structure has been described, but the present invention is not limited to the above detailed structure, and the second gear and the first gear are coaxial and rotatable. Instructed by the instructing means,
The first gear and the second gear are coaxially rotatable relative to each other by a predetermined angle, and a first torque is applied to the first gear and the second gear to urge them to rotate relative to each other. A rotation urging means that is rotated when receiving a turning force with a second torque that is greater than one torque in the opposite direction, and a first locking means that stops rotation while being urged to rotate with each other by the first torque. If the second locking means is configured so that the first gear and the second gear come into contact with each other and are stopped while being rotated by the second torque, the above-described actions and effects are exhibited.

[0143]

As described above, the image forming apparatus of the present invention is an image forming apparatus in which a cartridge having a driven portion which is equipped with a driven gear and is driven to rotate is detachable, and which meshes with the driven gear. Second gear that is rotationally driven by the first gear, a first gear that transmits drive to the second gear, a support unit that rotatably supports the second gear and the first gear coaxially, and the first gear and the second gear are coaxial. Means that can be relatively rotated by a predetermined angle on the wick, rotation urging means that applies a predetermined torque to the first gear and the second gear and urges them to rotate relative to each other, and mutually rotate with a predetermined torque. The first locking means that stops rotating in the state of being dynamically biased, and the first gear and the second gear come into contact with each other while the first gear or the second gear is rotated against the rotation biasing means. And a second locking means that stops by rotating the driven gear from the first gear through the second gear. When the cartridge is disengaged, the first gear and the second gear are arranged at positions where the driven gear can be disengaged when the cartridge is disengaged. When the first gear is rotationally driven and the driven gear is driven via the second gear, the rotational drive is stopped and the cartridge is taken out, the second gear and the driven gear arranged at positions where they can be disengaged from each other The meshing is released smoothly, the rotational drive load of the second gear is released, the second gear is rotated by the rotation biasing means, and the initial state is reached in which the first locking means stops the rotation.
On the other hand, this time, when the cartridge is mounted in this initial state, the driven gear is driven in a direction opposite to the normal rotation direction of the second gear due to the rotational driven load during the process in which the second gear and the driven gear reach the meshed state. Direction, that is, the second gear is mounted by rotating the second gear by a predetermined angle in a direction against the biasing force of the rotation biasing means. The cartridge can be easily attached and detached without difficulty, and when the cartridge is attached or detached. With respect to the relationship between the driven-side gear and the driving-side gear, the present invention can be configured with the simple structure as described above without constructing a complicated structure, so that simplification of the device is extremely easy. Yes,
It is beneficial for a compact structure and an inexpensive structure, and the practical effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a sectional view of a left side main part showing an embodiment of an image forming apparatus of the present invention.

FIG. 2 shows a first embodiment of the image forming apparatus of the present invention.
FIG.

FIG. 3 shows a second embodiment of the image forming apparatus of the present invention.
FIG.

FIG. 4 shows a first embodiment of the cartridge of the present invention.
FIG.

FIG. 5 shows a second embodiment of the cartridge of the present invention.
FIG.

FIG. 6 shows a first embodiment of the image forming apparatus of the present invention.
FIG.

FIG. 7 shows a second embodiment of the image forming apparatus of the present invention.
FIG.

FIG. 8 shows a first example of an image forming apparatus of the present invention.
FIG.

FIG. 9 shows a second embodiment of the image forming apparatus of the present invention.
FIG.

FIG. 10 is a third developed sectional view showing an embodiment of the image forming apparatus of the invention.

FIG. 11 is a sectional view of a right side main part showing an embodiment of the cartridge of the present invention.

FIG. 12 is a cross-sectional view of an essential part of the upper surface showing an embodiment of the cartridge of the present invention.

FIG. 13 is an explanatory diagram related to rotational driving showing an embodiment of the cartridge of the present invention.

[Explanation of symbols]

 1 Photosensitive Drum 2 Charging Roller 5,5A Supporting Member 7,7A Supporting Pin 8,8A Spring 10 Developing Section 12 Developing Sleeve 13 Supply Roller 17 Cartridge Upper Case 18 Cartridge Lower Case 20 Toner Tank 30,30a Toner Conveying Section 31,31a Coil Spring 40 Exposure device 42 Exposure device base 42a, 64a, 71a Positioned part 50 Control part 60 Fixing part 64 Fixing base 70 Paper feeding part 71 Sheet material conveying base 72 Paper feeding tray 73 Paper feeding roller 80 Transfer part 81 Transfer roller 90 Cleaner Part 92 Cleaning blade 100 Main chassis 100a Convex part 100c (as a positioning part) 100c 1st surface 100d 2nd surface 100e 3rd surface 100f Coupling part 101 1st wheel train receiving 101d, 101e Burring part 102 Wheel train 2nd Only 102c, 102d burring portion 102e projection portion C1 tumbler arm CS, FS, KS compression spring D # a first circumferential portion E # a second circumferential portion 103 driving motor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 1/00 108 Q

Claims (2)

[Claims] 1. An image forming apparatus in which a cartridge having a driven part, which is equipped with a driven gear and is rotationally driven, is detachable, and which is rotationally driven by meshing with the driven gear.
A gear, a first gear drivingly transmitted to the second gear, and a second gear
Support means for rotatably supporting the gear and the first gear coaxially; means for relatively rotating the first gear and the second gear by a predetermined angle on the coaxial core; and the first gear and the first gear. A rotation urging means for applying a predetermined torque to the two gears to urge the two gears to rotate with each other; a first locking means for stopping the rotation in a state in which the two gears are rotationally urged with each other by the predetermined torque; A second stop in which the first gear and the second gear come into contact with each other in a state in which the first gear or the second gear is rotated against the dynamic urging means.
Locking means, and a structure in which rotational drive is transmitted by the second locking means when the driven gear is rotationally driven from the first gear via the second gear. The gear and the second gear are arranged at positions where the driven gear can be engaged and disengaged when the cartridge is detached. 2. The image forming apparatus according to claim 1, wherein the driven gear is provided in a driven portion of a developing unit that develops toner on the photosensitive member or a latent image of the photosensitive member.