JP3314485B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

[0003]

As described above, according to the prior art, not only the apparatus is increased in size but also an expensive image forming apparatus.

[0004] By the way, in the environment surrounding computers these days, with the rise of small notebook computers, the downsizing has been spurred, and the market for personal use has expanded, so that it is possible to place the computers with sufficient margin on the desktop of individuals. As described above, there has been an increasing demand for the miniaturization of external terminals such as printers and facsimile machines corresponding to the miniaturization of computers and the appearance of inexpensive products.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to provide a simple structure with respect to the relationship between a driven gear and a driving gear which are disengaged when a cartridge is attached and detached. Thus, a cartridge can be easily attached and detached, the structure of the apparatus is simplified, and a small-sized and inexpensive image forming apparatus has emerged, which particularly meets the demand in the personal use market.

[0006]

SUMMARY OF THE INVENTION An image forming apparatus according to the present invention is an image forming apparatus having a driven portion provided with driven gears (L #, H #) and having a driven portion that is rotatable. , the driven gear (L #, H #) second gear that rotates in mesh with the (F2 #, K2 #) and said second gear (F2 #, K2 #) first gear that drive transmission to the
(F1 #, K1 #) , and the second gears (F2 #, K2 #) and the first gears (F1 #, K1 #) are coaxially and rotatably supported by supporting means (102b, 101c) (102e,
101e) , the first gear (F1 #, K1 #) and the second gear
Means (F1 # a, F1 # b, F2 # a, F ) in which gears (F2 #, K2 #) are coaxial and relatively rotatable by a predetermined angle.
2 # b) and said first gear (F1 #, K1 #) and the second formic <br/> Ya (F2 #, K2 #) Ru is rotationally biased together by applying a predetermined torque to the times Dynamic biasing means (FS, KS) and first locking means (F1 # b, F2 # b) (K1 #) which stop rotating while being biased to rotate by the predetermined torque.
b, K2 # b) and the first gear (F1 #, K1 #) or the second gear against the rotation urging means (FS, KS) .
When the gears (F2 #, K2 #) are rotated, the first gear
Second locking means (F1 # a, F2 # a) that stops when (F1 #, K1 #) comes into contact with the second gear (F2 #, K2 # ).
(K1 # a, K2 # b), and the first gear (F
1 #, K1 #) through the second gears (F2 #, K2 #) to rotate the driven gears (L #, H #) , the second locking means (F1 # a, F2 # a). ) (K1 # a, K2
#B) , the first gear (F1 #, K1 #) and the second gear
(F2 #, K2 #) is characterized in that the driven gear is disposed at a position where the driven gear can be disengaged when the cartridge is detached.

[0007]

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

FIGS. 1 to 13 show a preferred embodiment of a cartridge and an image forming apparatus according to the present invention. FIG. 1 is a sectional view showing a main part of a left side of the entire image forming apparatus according to the present invention. 3 is a cross-sectional view of a first main part, FIG. 3 is a cross-sectional view of a second main part, and FIG. 3 is a cross-sectional view at different positions. In each figure, the left side from the alternate long and short dash line is not shown.

FIG. 4 and FIG. 5 are cross-sectional views of main parts on the left side of the cartridge according to the present invention, and FIG.
FIG. 5 is a cross-sectional view of a main portion of the second left side surface, and each drawing is a cross-sectional view at a different position.

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

FIGS. 8, 9 and 10 are exploded sectional views showing a rotational drive transmitting portion of the image forming apparatus of the present invention. FIG. 8 is a first exploded sectional view, and FIG. 9 is a second exploded sectional view. , FIG. 10 is a third developed sectional view, each showing a different rotational drive path.

FIG. 11 is a cross-sectional view of a main part of the right side of the cartridge of the present invention, showing the relation of rotational drive.

FIG. 12 is a cross-sectional view of a main part of the upper surface of the cartridge of the present invention.

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

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 means of this embodiment is shown in FIG.
The photosensitive drum 1, the charging roller 2, the cleaner unit 90, the developing unit 10,
It is constituted by the toner conveying sections 30 and 30a.

Referring to FIG. 1, FIG. 4, and FIG. 5, the order of the image forming process will be described.
Is formed of a semiconductive elastic material such as rubber, for example, and is driven by the photosensitive drum 1 rotating in the direction of the arrow in FIG.
When a bias of (−) 2 kv or less is applied, the photosensitive drum 1 can be charged to a charging potential of (−) 600 V to (−) 700 V.

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 a light beam emitted from an exposing device 40 to be described later and incident from an optical path 49, and the potential of the image-exposed portion becomes (-). ) 50 V to (−) 150 V.

Next, in the developing section 10, a supply roller 13 formed of a semiconductive elastic material such as foamed rubber, for example, and rotating in the direction of the arrow in FIG. The toner in the storage unit 11 that stores the toner is coated on the surface of the developing sleeve 12 and rotated, and rubbed with the developing sleeve 12 formed of a semiconductive elastic body such as a rubber material that rotates in the direction of the arrow in the drawing. Is frictionally 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 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 area in the 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 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 the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 and the vicinity thereof. Reversal development is performed on the image exposure portion of the photosensitive drum 1.

Incidentally, the toner in the storage unit 11 is as shown in FIG.
As shown in detail in the cross-sectional view of the first main part of the left side of the cartridge, a cartridge upper case 17, a cartridge lower case 18, a regulating blade 14, a pressing member 16 of the regulating blade 14, a developing sleeve 12, The space surrounded by 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.

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

The cleaned photosensitive drum 1 can be transferred to the next image forming process again. If the potential remaining on the photosensitive drum 1 after cleaning is removed by light irradiation or the like, 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. A conventional image forming apparatus is mounted as a cartridge in which a predetermined amount of toner corresponding to the operating life of the main components such as a photoreceptor is enclosed in an integrated casing, which not only increases the size of the entire apparatus but also replaces it. Although the workability of maintenance is enhanced, the image forming apparatus is expensive, but 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 necessary minimum 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 development is dropped and replenished from the toner transport unit 30a that transports the toner, which will be described in detail 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 rake sheet 91 and the cleaning blade 92.
Move to zero.

As will be described in detail later, the toner conveying sections 30, 30a include toners including endless coil springs 31, 31a (separated for the sake of explanation in the drawing, but endless and integral). A mechanism for transporting the toner by the transporting means is provided, and the toner transporting units 30 and 30a, which are disposed at substantially horizontal left and right positions with the photosensitive drum 1 being substantially at the center in the figure, are formed by a structure described in detail later. The toners of the toner transport unit 30 and the toner transport unit 30a are connected and circulated and transported.

Next, the toner circulation function will be described. With respect to the amount of toner (development toner amount) in the storage unit 11 consumed by the above-described development, the amount of untransferred toner scraped off by the cleaning blade 92 and transferred to the toner conveyance unit 30 (reproduction toner amount) Is 10% to 30% in the present embodiment. Even if the toner is circulated and conveyed, the toner is consumed by the repetition of the development, Will decrease.

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 the transport path for circulating the toner, which will be described in detail later. Is supplied and circulated and transported together with the above-mentioned regenerated toner.
1 is configured to be replenished.

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 with reference to FIGS. 2, 4, 5, and 12. FIG.

The supply roller 13 made of a semiconductive elastic material such as foamed rubber and the developing sleeve 12 made of a semiconductive elastic material such as rubber are used as metal cores. The support members 12a and 13a are provided at both ends of the elastic body, and the support members 12a and 13a are rotatably supported by the support member 5 as shown in FIG. Have been. 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 support structure, and is rotatably supported by a support member 5A.

The supply roller 13 and the developing sleeve 1
4 is supported at a fixed pitch smaller than the pitch at which the outer circumference of the supply roller 13 and the outer circumference of the developing sleeve 12 are in contact with each other, and the outer circumferences of both rollers are uniformly contacted over the entire area in the longitudinal direction. , The positional relationship shown in detail in FIG.

Then, the supply roller 13 and the developing sleeve 1
Reference numeral 2 denotes a configuration in which each of the rollers 2 is driven to rotate in the direction of the arrow shown in the drawing to rub, and when the distance between the support pitches is extremely reduced, the rotational driving torque increases, or the toner rubs between the two roller nips. In view of absorbing the dispersion of the components related to the support, in the present embodiment, the supply roller 13 and the developing sleeve 12 are supported at a fixed pitch 0.2 mm narrower than the contact pitch between the outer circumferences of the developing sleeve 12.

A supporting member 5 and a supporting member 5A which rotatably support both ends of a supply roller 13 and a developing sleeve 12, respectively.
Are firmly connected via a connecting member 6 by a fixing means such as a screw or the like to form an integral structure. As shown in FIG. 12, the supporting member 5 is a supporting pin 7 inserted through a part of the cartridge lower case 18. 12 shows a state in which only one side is supported, but the opposite side has the same support structure, and the support member 5A is a support pin 7A that 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
In a state where both ends are rotatably supported and connected by the connecting member 6, the support pin 7 and the support pin 7A are used as support shafts together with the regulating blade 14, so that the image forming process described above is not hindered. In the space of the toner storage unit 11 configured to minimize the storage amount, the photosensitive drum 1
Can be integrally rotated with respect to.

When the support pin 7 and the support pin 7A are arranged at the positions shown in FIGS. 4 and 5, the cartridge lower case 18 and the support member can be easily rotated based on the above-mentioned integrated structure. The gap between the support member 5 and the support member 5A is configured to be free in the rotation direction, and this gap is blocked 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,
Also provided are springs 8 and 8A that set the hooks at both ends to the cartridge lower case 18 and apply the tension to the support member 5 and the support member 5A to urge the developing sleeve 12 toward the photosensitive drum 1.

With respect to the support member 5 and the support structure of the support member 5A by the support pin 7 and the support pin 7A, in this embodiment, as a means for preventing a rotation problem even if a difference occurs between the left and right support positions. In one of the support portions, the support pins 7 of the cartridge lower case 18 and the support member 5 are provided.
Is formed in the same circular shape as the support pin 7, and the other support portion through which the support pin 7A of the cartridge lower case 18 and the support member 5A is inserted is the support pin 7A. An oblong opening 18b which is movable toward and away from is formed to prevent the occurrence of a rotation problem of the above configuration.

In this embodiment, the opening 18b of the oval shape is formed in the lower case 18 of the cartridge. On the contrary, the opening 18b of the lower cartridge 18 is made a circular opening and the opening on the side of the support member 5A is made oval. Even if the openings may be 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 springs 31 and 31a for circulating and conveying the toner are combined with the cartridge upper case 17 and the cartridge lower case 18.
The toner tank 20 is configured to be detachable (the attachment / detachment mechanism is not shown in detail in the drawing), and a predetermined amount of toner is enclosed therein. The toner is replenished and replaced with a new toner tank 20 when the toner is consumed.

The endless coil springs 31 and 31a for circulating and transporting the toner are denoted by reference numerals for convenience of explanation in the drawing, but are endless and integrated, and are shown in FIG.
Although the left side is omitted from the alternate long and short dash line, it is configured endlessly.

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, and a tank case 21 and a cover 22. Plural blades 23 that stir rotatable toner sealed with toner
b), and endless coil springs 31 and 31a for circulating and conveying the toner are detachably operable in a state where the coil springs 31 and 31a are enclosed by the cartridge upper case 17 and the cartridge lower case 18. (Detailed illustration omitted).

On the other hand, in order to drive the endless coil springs 31 and 31a for circulating and transporting 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 circulated and movable. The drive means 25 for the coil springs 31 and 31a is arranged in a part of the arrangement path of the springs 31 and 31a.
7, when the toner tank 20 is mounted at a predetermined position, the rotatable convex portion 25a formed in a wedge shape and the concave portion 23c formed at one end of one agitator 23 are engaged to rotate. Is done.

The drive means 25 of the endless coil springs 31 and 31a for circulating and conveying the toner can be driven by a rotating body that can be engaged with the coil springs 31 and 31a. The engagement relationship with the coil springs 31, 31a is stabilized by employing a helical gear having a twist angle approximating the lead angle of the stretched state of the 31, 31a.

One agitator 2 driven by the above configuration
A gear portion 23 a is formed on the part 3 and the other agitator 23, and the gear portion 23 a is rotatably connected by an idle gear 24.

The toner agitated by the rotation of the agitator 23 circulates and transports the toner through an opening 21a formed at the bottom of the tank case 21 and an opening 17a of the cartridge upper case 17 provided opposite the opening 21a. Endless coil springs 31, 31a
Is dropped by its own weight into the toner circulation / conveying path in which the toner tank 20 is disposed.
1a and opening 17a are opened and closed. (Not shown) The toner dropped by its own weight in the toner circulating conveyance path in which the coil springs 31 and 31a are disposed is circulated and conveyed in the direction of the arrow in FIG.
At 0a, the toner drops from the upper part of the supply roller 13 under its own weight and is stored in the toner storage unit 11 described above with reference to FIG. 4, but as described above, the toner storage unit 11 is configured to be extremely 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 is circulated and conveyed by the coil springs 31 and 31a without falling by its own weight. The structure is such that the fall of the toner from the toner tank 20 by its own weight is also interrupted.

The above is the main part of the image forming means of this embodiment. The photosensitive drum 1, the charging roller 2, the cleaner 90, the developing unit 10, and the toner conveying units 30, 30a are arranged in the above-described relationship. A cartridge lower case 18 which mainly serves as a main part and a cartridge upper case 17 which also plays a role of a cover thereof can be detachably attached to the main body as a cartridge having a unit structure. To perform repair or replacement.

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

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

Then, 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. Is formed, and the third surface 100e is configured to have a coupling portion 100f in which both are fitted in a process of bending the first surface 100e, the second surface 100d, and the third surface 100e.
Are easily achieved with high accuracy, and the connecting portion 10
It is also highly rigid due to the utility of 0f.

It is to be noted that although the connection portion 100f is effective even if both are fitted together, in this embodiment, in order to further increase the stability, the connection portion 100f is subjected to a caulking fastening treatment. It is.

Next, the transfer section 80 for transferring the reversely developed toner image to the image exposure section of the photosensitive drum 1 will be described.

The main part of the transfer 80 in this embodiment is pressed toward the photosensitive drum 1 by a total pressure of several hundred g from below by a pressing mechanism (not shown), and is inverted to a latent image of the image exposure part of the photosensitive drum 1. D of the opposite polarity to the developed toner image
A means for applying a bias of about C1KV,
The transfer roller 8 includes a rotatable transfer roller 81 made of a conductive or semiconductive elastic material such as rubber, and a main component of a sheet material transporting unit 70 described later in detail.
1 and is positioned at a predetermined position by engagement of a positioning portion 71a with a positioning portion formed on a main chassis 100, which is a reference of an internal configuration of the apparatus. It is fixed to the main chassis 100 by fixing means such as screws.

The toner image conveyed to the nip formed by the pressing action of the photosensitive drum 1 and the transfer roller 81 is connected to the sheet material fed from a sheet material conveying unit 70 described later in detail. It is transferred and merged.

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 a fixing roller which is disposed on the downstream side in the sheet material conveying direction and has a built-in heating element such as a halogen heater as a heating means in a hollow part of the aluminum pipe material and is rotatable. As a pressing means for pressing the toner image transferred to the sheet material onto the sheet material, a pressing mechanism composed of a lever 66 which is pressed and displaceable by a pressing member such as a spring or the like, can move several kg to the fixing roller 63 by a pressing mechanism. A pressure roller 67, which is pressed at a total pressure and is formed on at least a 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. An operation lever 6 which 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, a cam 69 which is displaced in the direction of the arrow in FIG. 1 in conjunction with the rotation of the operation lever 68 to control the displacement of the lever 66, and a discharge roller pair 6 which discharges the conveyed sheet material to the outside of the apparatus.
1 and a fixing base 64 that supports the fixing members and supports the fixing unit 60 in a unit configuration. The fixing base 64 is attached to a positioning unit formed on the main chassis 100 which is a reference of the internal configuration 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 fixing means such as screws.

The toner image transferred from the transfer section 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.

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 is provided at the rear of the apparatus and accommodates a large number of sheet materials P such as paper, is formed by feeding the sheet material P at its lower end with a high frictional material such as rubber. Part 7
A well-known pressing mechanism 74 that selectively presses the paper feed roller 73 that can rotate freely is provided, and is detachably supported on the apparatus main body.

The sheet feeding section 70 on the apparatus main body side is arranged to face the sheet feeding roller 73 with the sheet material P interposed therebetween, and only the uppermost sheet material among the many sheet materials P is fed to the sheet feeding roller 73. A sheet feed control mechanism 75 for separating the sheet so that the sheet is fed by the rotation of the sheet 73 and for preventing the second and subsequent sheets from being fed; A sheet material guide 76 disposed to form a sheet material conveyance path, sheet material detection means 77 including a photosensor and the like disposed in the sheet material conveyance path and detecting the presence or absence of a sheet material; An operation lever 6 operable from the front surface of the fixing unit 60, which is not shown but is constituted by a sheet material conveying base 71 that supports the transfer roller 81 described above, together with the main components of the unit 70. And 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. The unit 70 and the transfer unit 80 are supported in a unit configuration by a sheet material transport base 71. As described above, the sheet material transport base 71 is covered by a positioning unit formed on the main chassis 100, which is a reference of 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.
00 is fixed.

When the sheet supply 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 in response to a detection signal of the sheet material detecting means 77, the sheet feeding roller 73
The sheet is stopped in a state where the sheet material is sandwiched, and a standby state (standby state) for the above-described transfer is performed.

The timing of stopping the sheet feeding roller 73 may be stopped by a detection signal of the sheet material detecting means 77. However, after a predetermined time elapses from the detection signal by a delay means such as a timer, it is stopped and waits. May be.

That is, the toner image reversely developed on the image exposure portion of the photosensitive drum 1 at the nip portion formed by pressing the developing sleeve 12 and the photosensitive drum 1 against each other 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 unit 80 having the nip formed by pressing and the time required for the sheet material to reach the transfer unit 80 by feeding the sheet material from the standby state. In this embodiment, the latter is adopted.

In the present embodiment, a sheet material detecting means 77 including a photo sensor for detecting the presence or absence of a sheet material is disposed in the sheet material conveying path of the sheet feeding section 70, and the other is omitted from the drawing. However, a second sheet material detecting means similar to the nip portion formed by the pressing action of the fixing roller 63 and the pressing roller 67 of the fixing unit 60 is provided on the downstream side in the sheet material conveying direction, and the sheet material conveyance state is determined. Detected, the detection signal from the sheet material detecting means 77 and the detection signal from the second sheet material detecting means are processed in a predetermined relationship to monitor the jam state in the apparatus.

Incidentally, the image forming apparatus of this embodiment is compactly configured,
In the case of a jam on the side, the sheet material is pulled out to the rear of the apparatus, and in the case of the jam on the fixing unit 60 side, the pressing force of the pressing roller 67 against the fixing roller 63 by operating the operation lever 68 operable from the front of the apparatus. Further, the pressing of the transfer roller 81 against the photosensitive drum 1 is released, and the sheet material is pulled out to the front of the apparatus so that the sheet material 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 includes a motor 41 rotating at 10,000 rpm, a control circuit board (not shown) for controlling the rotation of the motor 41, and a motor 41.
A deflection scanning means 43 which is mounted on the output shaft of the scanner and rotates and deflects and scans 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 to be formed,
An exposure unit case 42 is formed by housing the above-mentioned main constituent members to form a unit. The exposure unit case 42 is engaged with a positioning portion 42a with respect to a positioning portion formed on a main chassis 100, which is a reference of an internal configuration of the apparatus. It is positioned at a predetermined position depending on the case, and is fixed to the main chassis 100 by fixing means such as a screw.

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

Next, a description will be given of the control section 50 which controls the above-described respective mechanical sections. The main part of the control unit 50 is arranged at the lowermost end of the apparatus, and at least a power supply circuit unit and an operation control circuit unit of each mechanism unit are arranged. Although not shown, an interface connector for receiving an external signal and a power supply unit are provided. Connection means related to input and output such as input connectors are connected,
The control unit 50 is compactly and centrally arranged.

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

The main part of the drive transmission unit of the present embodiment is concentrated on the right side surface of the main chassis 100, that is, the third surface 100e, and the first train wheel receiver 101 and the second train wheel receiver 1 are arranged.
02 are provided opposite to each other, and a drive motor 103 having a drive gear 103a on an output shaft and several kinds of drive gear trains to be described later are rotatably supported on the two wheel train receivers to form a unit structure. Main chassis 100 as a reference for configuration
The positioning portion is positioned at a predetermined position by the engagement of the positioning portion with the positioning portion formed on the third surface 100e, and is fixed by fixing means such as screwing.

In the present embodiment, the first wheel train 101 and the second wheel train 102 are formed in a sheet metal structure, and will be described later in detail. Is the feature.

Referring to FIGS. 6 and 7, the entire driving system of the present embodiment will be described. 6 and 7 are cross-sectional views of a main part of a right side showing a suitable embodiment of a drive system used in the image forming apparatus of the present invention. Each of the drawings is a cross-sectional view at a different position, and FIG. FIG. 7 includes the first train wheel receiver 101 and the second train wheel receiver 102, and FIG. 7 omits these two train wheel receivers to make it easier to see each gear train for simplicity. In both FIGS. 6 and 7, the center of rotation of each gear is indicated by a + sign 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
A description will be given for each individual drive system after the common A # gear driven by a.

<First Driving System> The first driving system for rotating the photosensitive drum 1 is A
The gears are driven in the order of # gear → J # gear → K # gear → L # gear. The L # gear (driven gear) is a gear fixed to one end of the photosensitive drum 1 by a fixing means such as an adhesive. 1 and connected to or disconnected from the first drive system when the above-described cartridge is attached or detached.

The mounting and dismounting of the cartridge in this embodiment is performed by moving the cartridge in the vertical direction in the figure.

<Second Drive System> The second drive system for rotating and driving the developing sleeve 12, which is a main component of the developing unit 10, is an A # gear → B # gear → C # gear → F # gear →
The gears are driven in the order of the 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 to or disconnected from the second drive system.

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

<Fourth Driving System> The driving device 25 for driving the endless coil springs 31 and 31a for circulating and conveying the toner and the fourth driving system for rotating the agitator 23 of the toner tank 20 are A # gears. The gears are driven in the order of B # gear → C # gear → F # gear → H # gear → V # gear (V # gear is shown in FIG. 6). Helical gear fixed by the fixing means of
The gear (driven gear) is the cartridge lower case 18 described above.
A helical gear rotatably supported by a gear H # (a driven gear )
Ya) is connected to or detached to the fourth drive system

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

<Sixth Driving System> The sixth driving system for rotating the fixing roller 63 is A # gear → P # gear → Q
The gears are driven in the order of # gear → R # gear. The R # gear is a gear provided at one end of the fixing roller 63 described above, and is always connected to the sixth drive system.

<Seventh Drive System> The above-described discharge roller pair 61
The seventh drive system that rotationally drives the A # gear → P # gear →
The gears are driven in the order of S # gear → T # gear → U # gear, and 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 of the present embodiment, each main part is driven in a distributed manner while avoiding a monotonous concentration of the rotational driving force.

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

<First driving system> A # gear → J # gear → K # gear → L # gear (driven gear
The first drive system for rotatingly driving the photosensitive drum 1 driven in the order of ( d) has a structure shown in detail in FIGS. 8 and 11.
FIG. 8 is an expanded 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 the inner surface 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 a J # gear rotatably supported via a push Ja pressed and held in the projection portion 101b of the receiver 101 to drive the L # gear (driven gear ).
Ya) .

Here, as described above, the L # gear (driven
Gear) is connected to or disconnected from this drive system by the attachment / detachment of the cartridge. In this embodiment, the K # gear is used as a means for facilitating the meshing relationship between the K # gear and the L # gear (driven gear) at the time of attachment / detachment. To the K1 # gear (No.
1 gear) and K2 # gear (2nd gear)
One K1 # gear (first gear) is rotatably supported by a burring portion 101c (supporting means) formed on the first wheel train 101 with a mirror-finished inner surface, similarly to the A # gear.
The other K2 # gear (second gear) is provided with one end facing the train wheel first receiver 101 and has a projection portion 102 of a train wheel second receiver 102 formed with its outer peripheral portion formed in a mirror-finished state.
b is supported by (supporting means), K2 # gear other end (second gear) is rotatably supported by inserting into the interior of K1 # gear (first gear), the K1 # gear (first gear ) And K2 # gear
The (second gear) is configured to be rotatable integrally, and the K1 # gear (first gear) and the K2 # gear (second gear) in the figure.
As shown in FIG.
A concave portion K1 # a in the 1 # gear (first gear) (second locking means)
And the protrusions K1 # b (first locking means) are formed at point-symmetric positions, respectively, and the recesses K2 are provided in the recesses K1 # a (second locking means) .
The other K2 # gear (second gear) in which #a and the convex portion K2 # b (second locking means) are respectively formed at point-symmetric positions is inserted to be rotatable relative to each other by a predetermined angle. A compression spring KS is arranged in both the concave portions K1 # a (second locking means) and K2 # a, and both of the convex portions K1 # b (the second 1 locking means) and K2 # b (the
(2 locking means) abuts and maintains the stopped state (section A in section A)
And K2 # gear (second gear) and L # gear (driven
Gear) meshes with each other.

When the K1 # gear (first gear) is rotationally driven in the direction of the arrow in the figure, as shown in section 2 as viewed in A,
Within a short period of time, the K2 # gear (second gear), which is engaged with the L # gear (driven gear) and has a rotational load, is stopped and the compression spring KS is compressed to cause the K1 # gear (first gear ).
) Only rotates, and the second convex portions K1 # c and K2 # gear (second gear) formed at point-symmetric positions of the K1 # gear (first gear).
A second protrusion K2 # c formed on the point symmetry positions of Ya) abuts, K2 # gear (second gear) to rotate in the direction of the arrow in FIG L # gear (driven gear) 11 in It is configured to be driven in the direction of the arrow.

In the above configuration, the L # gear (driven gear) is driven in the direction of the arrow in FIG.
When the above-described cartridge is taken out upward in FIG. 11, L #
Since the gear (the driven gear) and the K2 # gear (the second gear) are arranged at positions where they can be disengaged from each other, their meshing is disengaged without difficulty and the rotational driving load of the K2 # gear (the second gear) is reduced. The compression spring KS (rotation biasing means) is extended, and the K2 # gear (second gear) is rotated in the direction of the arrow A in section A in FIG. And, on the other hand,
Next, when the cartridge is mounted from above in FIG. 11 in the state of the cross section 1 as viewed from A, the L # gear (driven gear) and the K2 #
The L # gear (the driven gear) is changed to the K2 # gear (the second gear) by the above-mentioned rotational driving load generated by the pressure contact between the photosensitive drum 1 and the developing sleeve 12 in the process of the gear (the second gear) reaching the meshing state . Gear ( K2 # ) (second gear) shown in FIG. 11 by a predetermined angle against the extension direction of the compression spring KS (rotation biasing means) . It is a structure that is mounted by turning clockwise.
Even if the 2 # gear (second gear) is turned counterclockwise by a predetermined angle, the second convex portion K1 # c and the second convex portion K1 # c do not reach the state of section 2 in FIG. The relationship between the protrusions K2 # c is configured.

The drive motor 103 of this embodiment is
An inexpensive PM type stepping motor is used, and smooth continuous rotation driving is enabled by controlling input pulses 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 rotatingly driving the developing sleeve 12, which is a main component of the first drive system, has a structure shown in detail in FIGS. 9, 10 and 11, and FIG. 9 and FIG. It is illustrated.

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 second drive system, and the description is omitted. The description of the driving after # gear will be given.

The A # gear is connected to a C # gear via a pair of B # gears rotatably supported via a push Ba press-fitted and held in a burring portion 102c provided in the second train wheel receiver 102. Further, the F # gear is driven (FIG. 10), and the rotational drive reaches the G # gear. Note that the C # gear in FIG. 9 and the C # gear in FIG. 10 are the same.

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 an oval-shaped engaging portion and an engaged portion shown by B in the figure. And can rotate together.

[0097] The C # gear of the next gear train is a 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.

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 and a tumbler function to be described in detail later, and the other end of the tumbler arm C1 is formed in the wheel train first receiver 101 by mirroring the inner surface thereof. The main shaft C2 rotatably supported by the burring portion 101d and the tumbler arm C1 and a flange portion of the main shaft C2 are guided in the thrust direction. The main shaft C2 is driven by the free C2 # gear and the oval engagement portion and the engaged portion shown by C in FIG.
And a C1 # gear that is rotatable integrally with the C1 # gear, and rotates the G # gear from the C2 # gear via the F # gear.

The F # gear is composed of F1 # gear (first gear) and F2
# Gear (second gear) and one F2 # gear ( second gear) like the K # gear of the first drive system described above.
Ya) of the wheel train the inner surface to the first receiving 101 and to the burring portion 101e (support means formed) thus rotatably supported on the mirror surface, the other F1 # gear (first gear) is wheel train first one end The gear train 2 is supported by a projection portion 102e (supporting means) of a second train wheel 102 provided so as to face the receiver 101 and having an outer peripheral portion formed in a mirror-finished state .
The other end of the gear) is rotatably supported by inserting into the interior of F2 # gear (second gear), the F1 # gear (first gear) and F2 # gear (second gear) together form It is rotatable. (For the double structure of the F # gear,
Here, as described above, G #
Since gear configuration for connection or detachment by removable cartridges F1 # gear of the second drive system (first gear), in this example F1 # gear (first formic In this detachable
As means for facilitating the meshing relationship between the gear (G ) and the G # gear, a mechanism for performing the same operation as the K # gear of the first drive system on the C # gear is configured.

That is, the C2 # gear and the main shaft C2 in FIG.
Heavy structure, F1 # gear (first gear) and F2 # gear
As shown in the BB section of the double structure portion of the (second gear) , a concave portion C2 # a and a convex portion C2 # b are formed in one C2 # gear at point-symmetrical positions, respectively. Recess C
The other main shaft C2 in which the protrusions 2a and the protrusions C2b are respectively formed at point symmetrical positions is inserted and rotatable relative to each other by a predetermined angle, and is shown in both recesses C2 # a and C2a. A simplified compression spring CS is provided, and the two projections C2 # b and C2b are urged to rotate in one direction to abut against each other to maintain a stopped state (BB section 1). The gear and the F1 # gear (first gear) are structured to 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 BB section 2, it is engaged with the F1 # gear (the first gear) within a short time and rotates. With the C2 # gear having a load stopped, the compression spring CS is compressed, and only the main shaft C2 rotates, and the main shaft C
The second convex portion C2c formed at the point symmetrical position of the C2 # gear and the second convex portion C2 # c formed at the point symmetrical position of the C2 # gear abut,
C2 # and drawing is rotated in the arrow direction of gear F1 # gear (second
(1 gear) .

In the above configuration, when the main shaft C2 is driven in the direction indicated by the arrow in FIG. 11, the rotation is stopped, and the cartridge is taken out upward in FIG. 11, the G # gear and the F1 # gear are removed. Since the (first gear) is disposed at a position where the system can be disengaged from each other, the meshing of the (first gear) can be easily separated and the F1 # gear can be disengaged.
The rotational driving load of the C2 # gear is released together with the (first gear) , and the compression spring CS expands to move the C2 # gear to B in FIG.
By rotating the BB section 2 in the direction of the arrow, the BB section 1
On the other hand, when the cartridge is mounted from above in FIG. 11 in the state of the BB section 1, the G # gear and the F1 # gear (the first gear) are engaged in the above-described process. The G # gear is driven via the F1 # gear (first gear) by the rotational driving load generated by 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. C2 #
The gear is mounted in a direction opposite to the normal rotation direction, that is, by rotating the 2 # gear of FIG. 11 counterclockwise by a predetermined angle against the extension force of the compression spring CS. The second convex portion C2c and the second convex portion C2 # so that even if the C2 # gear is rotated counterclockwise by a predetermined angle, the gear does not reach the state of the BB section 2 in FIG. The relationship of c is configured.

<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 rotating and driving the supply roller 13, which is a main component of the first drive system, has a structure shown in detail in FIGS. 9, 10 and 11, and FIG. 9 and FIG. It is illustrated.

Referring to FIG. 9 and FIG.
The driving from the 3rd gear to the C # gear is the same as that described in the second driving system, and therefore 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 with the inner surface of the second train wheel receiving member 102 in a mirror-finished state, is shown in FIG. The other end has a bearing portion C1a for rotatably supporting the D # gear at the other end, and is inserted into an opening 102f formed in the second train wheel train 102 to be rotatable by both play clearances. Regulated.

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

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

In FIG. 11, in the planetary drive mechanism of this 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 of 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 movement moves toward the E # gear while performing the planetary motion of rotating and revolving, and this planetary urging action is performed even when the load of the E # gear is present.
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.

Based on this planetary drive mechanism, D # gear and E #
In this embodiment, as a means for stabilizing the meshing state of the gears, 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 the two are in contact with each other so as to be rotatable, and the first circumferential portion D # a is rotatable.
And the second circumferential portion E # a is in a contact state between the pitches D #
The relationship is established such that moderate backlash occurs when the gear and the E # gear mesh.

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

In the above configuration, the C # gear (C1 # gear) is shown in FIG.
1 When the rotation is stopped after being driven in the direction of the middle arrow, the D # gear and the tumbler arm C1, which are biased by the planetary drive mechanism by the planetary movement, are released from the biasing force and are in a free state. When the above-described cartridge is taken out upward in FIG. 11, the D # gear moves in the direction away from the E # gear, and it is extremely easy to take out the cartridge.

On the other hand, if the cartridge is mounted from above in FIG. 11 in the state after the cartridge is removed, the D # gear and the E # gear are in a state of meshing or having a play gap. C # gear (C1 # gear)
11 is driven in the direction of the arrow in FIG. 11, the D # gear moves in the direction approaching the E # gear while carrying out the planetary motion, even with or without the load of the E # gear. Gears mesh.

When 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
Is released from the urging force and is in a free state, so that the D # gear moves to a predetermined position while meshing with the E # gear.

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

As the rotational load increases, D #
The planetary urging force on the gears is particularly large in the direction of the pressure angle of the gear at the point of engagement of the C1 # gear and the D # gear, and the D # gear approaches the E # gear. However, the above-mentioned first circumferential portion D # a
The urging movement is regulated by the abutting state of the second peripheral portion E # 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> A # gear → B # gear → C # gear → F # gear → H # gear
(Driven gear) → V # gear (shown in FIG. 6) A drive means 25 for driving endless coil springs 31 and 31a for circulating and conveying toner driven in order and a driving means for rotating the agitator 23 of the toner tank 20. The four drive system has the structure shown in detail in FIGS. 9, 10 and 11, and FIGS. 9 and 10 are exploded sectional views of the first drive system.

Referring to FIG. 9 and FIG.
The driving from the 3rd gear to the F1 # gear (first gear) is the same as that described in the second drive system, and therefore the description is omitted.
The description of the driving from # gear (first gear) will be given.

As described above in the section of the second drive system, the F # gear (first gear) is connected to the F1 # gear ( first gear) similarly to the C # gear .
Gear) The F2 # gear (second gear) has a double structure, and the F2 # gear (second gear) is an H # gear (driven).
Gear) to drive the V # gear.

Here, as described above, the H # gear (driven
Gear) is connected to or disconnected from the F2 # gear (second gear) of the fourth drive system by attachment / detachment of the cartridge .
As a means for facilitating the meshing relationship between the gear # ) and the H # gear (driven gear) , a mechanism for performing the same operation as the above-described C # gear of the second drive system on the F # gear is configured.

That is, the C2 # gear and the main shaft C2 in FIG.
Heavy structure, F1 # gear (first gear) and F2 # gear
As shown in the BB section of the double structure portion of the (second gear) , a concave portion F1 # a (place ) is formed in one F1 # gear (first gear).
A means capable of rotating by a predetermined angle ) and a convex portion F1 # b (a predetermined angle).
The degree min pivotable means) is formed in each point symmetric position, the recess F1 # a (concave at a predetermined angle component rotatable means) in F2 # a (predetermined angle component rotatable means) And convex part F2 #
b The other F2 # gears (second gears) , each of which is formed at a point symmetrical position (means capable of rotating by a predetermined angle ), are inserted and rotatable relative to each other by a predetermined angle. A compression spring FS (rotation biasing means), which is simplified in the drawing, is disposed in both of the recesses F1 # a and F2 # a (second locking means), and both are biased in one direction to rotate both. Convex part F1 #
b and F2 # b (first locking means) are in contact with each other to maintain the stopped state (BB section 1), and the F2 # gear (second gear)
And an H # gear (driven gear) mesh with each other.

Then, from F1 # gear (first gear) to F2
When # gear (second gear) is driven to rotate in the direction of the arrow in the figure,
As shown in BB section 2, H #
F2 # gear (second gear) meshing with the gear and having a rotational load
While the gear ( F ) remains stopped, the compression spring FS (rotating urging means) is compressed, and only the F1 # gear (first gear) rotates, and
#Second convex portion F formed at a point symmetric position of gear (first gear)
The second convex portion F2 # c formed at a point symmetrical position between the 1 # c and the F2 # gear (the second gear) abuts on each other, and the F2 # gear (the second gear ).
) Is rotated in the direction of the arrow in the figure to drive the H # gear.

In the above configuration, the F1 # gear (first gear) is driven in the direction of the arrow in FIG.
When the above-mentioned cartridge is taken out upward in FIG.
# Gear (second gear) and H # gear (driven gear)
Since it is arranged at a position where it can be engaged and disengaged, the meshing is disengaged without difficulty, the rotational drive load of the F2 # gear (second gear) is released, and the compression spring FS (rotation biasing means) expands. The F2 # gear (second gear) is rotated in the direction of the arrow BB section 2 in FIG.
On the other hand, when the cartridge is mounted from above in FIG. 11 in the state of section B-B 1, the F2 # gear (second gear)
In the process in which the V # gear and the H # gear (driven gear) are engaged with each other, the V # gear is driven by the rotation driving load related to the driving means 25 for driving the endless coil springs 31 and 31a for circulating and conveying the toner. The H # gear (driven gear) is in a direction opposite to the normal rotation direction of the F2 # gear (second gear) , that is, the compression spring FS (rotating bias).
11 ) (the second gear ) of FIG.
10) is mounted by rotating the F2 # gear (second gear) counterclockwise by a predetermined angle by rotating the F2 # gear ( counterclockwise ) by a predetermined angle. BB
The relationship between the second convex portion F1 # c and the second convex portion F2 # c is configured so as not to reach the state of the cross section 2.

By the way, since the fourth drive system has the above-described double gear structure in series with the C # gear and the F # gear, the H # gear (driven gear) is used when the cartridge is mounted.
And F2 # gear (second gear) G # gear and F1 # gear ( second gear)
When the above operation is performed by meshing before the first gear, the operation is performed in the configuration of the F # gear, which affects the meshing of the G # gear and the F1 # gear (first gear) meshed later. The balance between the biasing torques of the respective gears biased by the compression spring CS and the compression spring FS (rotating biasing means) is taken into consideration so that independent operation is possible.

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

In the present embodiment, in the relationship between the drive section on the main body side and the driven section on the cartridge side, the drive force or the driven force is prevented from being concentrated at one pole, and both need not have a highly rigid structure. The configuration is decentralized so that it can be made compact and inexpensive. First, the specific contents will be described.

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

<First Driving System> The direction of action of the force for driving the L # gear (driven gear) from the K2 # gear (second gear) is in the direction of arrow L obliquely upward and leftward in the figure.

<Second Driving System> The acting direction 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 K2 # gear (the The direction in which the force for driving the L # gear (the driven gear) from the second gear) is different from the arrow L in the direction of the angle αG, and the specific angle in this embodiment is approximately 95 deg.

<Third Drive 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 the K2 # gear (the The direction of action of the force for driving the L # gear (driven gear) from the second gear) differs from the arrow L in the direction of the angle αE, and the specific angle in this embodiment is approximately 55 deg.

[0131] <Fourth driving system> F # direction of action of the force for driving the H # gear (driven gear) from the gear is an arrow H direction towards the right obliquely upward in the drawing, the K2 # gear (second 2 gears) to L # gear (driven)
The direction in which the force for driving the gear is applied is different from the direction of the arrow L by αH, and the specific angle in this embodiment is approximately 85d.
eg.

As described above, in the present embodiment, the K2 # gear
The endless coil spring 31 that circulates and transports the toner with the developing sleeve 12 and the supply roller 13 that form the main part of the developing unit 10 with respect to the direction L of the force acting on the photosensitive drum 1 from the (second gear). , 31a and the agitator 23 of the toner tank 20
The directions of action of the forces for driving the rotation are different directions, and furthermore, the action positions of the forces are dispersed, and the driven portion on the cartridge side or the drive portion on the main body side has high rigidity. The structure does not need to be configured.

The above is the relationship of each driving system which is configured to avoid the concentration of the driving force on the main body side or the driven force on the cartridge side in the present embodiment. When combined, the direction becomes the direction of arrow T which is directed obliquely upward in the figure, and the direction of action of the force for driving the photosensitive drum 1 from the K2 # gear (second gear) differs from the direction of arrow L by αT in the direction of the angle. Since the action direction arrow L and the action direction arrow T do not act in series, when the cartridge is fixed, the fixing force can be reduced.

The direction of the pressure angle of the gear at the meshing point between the drive gear on the main body side and the driven gear on the cartridge side may vary by about ± 15 deg due to the attachment / detachment of the cartridge or the variation in the configuration of each component. In the configuration of the present embodiment, it is necessary to consider at least the driving force acting in the direction of the arrow T that is substantially combined with the driving force of the K2 # gear (second gear) for driving the photosensitive drum 1. The above-mentioned effect is exerted by acting in a different direction over the region parallel to the lines L1 and L2 shown in FIG.

On the other hand, attention will now be paid to the structural 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 developing unit 10.

As described above with reference to FIGS. 4, 5 and 12, the supply member 13 and the support member 5A, which rotatably support both ends of the supply roller 13 and the development sleeve 12, which are main parts of the development section 10, are connected. For example, as shown in FIG. 12, the supporting member 5 is firmly connected to the cartridge lower case 1 through a member 6 by a fixing means such as a screw.
The support member 5A is rotatably supported by a support pin 7 inserted into a part of the cartridge lower case 8, and FIG. 12 shows a state in which only one side is supported. Support pin 7 inserted through part of 18
A is rotatably supported by A and is configured to be integrally rotatable with respect to the photosensitive drum 1 around the support pin 7 and the support pin 7A as a support shaft together with the above-described regulating blade 14, as shown in FIG. By the action of the driving force acting on the second drive system in the direction of arrow G and the action of the driving force acting on the third drive system in the direction of arrow E, the main part of the developing section is supported around the support pin 7 in the drawing. The developing unit 10 is urged to rotate in the direction of arrow 110, that is, the direction in which the developing unit 10 is separated from the photosensitive drum 1.

Therefore, in the above-described configuration of the present embodiment, the nip width is stabilized without causing an excessive driving force due to the occurrence of a biting phenomenon in the rubbing nip portion between the photosensitive drum 1 and the developing sleeve 12. As described above, the drive operation positions of the photosensitive drum 1 and the developing section 10 are dispersed, and the driven section on the cartridge side or the drive section on the main body side does not need to be configured to have high rigidity. Since there is no concentrated load state on the driven part on the cartridge side or the driving part on the main body side, vibration and chatter are suppressed, and driving with little rotational jitter is possible.

In this embodiment, as described above, in order to form a stable nip by pressing the developing sleeve 12 and the photosensitive drum 1 in the above state, both ends are set in the cartridge lower case 18 and the supporting member 5 is set. And the springs 8 and 8A for applying the tension to the support member 5A to urge the developing sleeve 12 in the direction of the photosensitive drum 1, so that the main part of the developing section is supported by the support pin 7 as a support center as described above. Thus, even when the photosensitive drum 1 is rotated and urged in the direction of arrow 110 in the drawing, that is, in the direction away from the photosensitive drum 1, a stable nip between the developing sleeve 12 and the photosensitive drum 1 is formed.

The above-described embodiment will be summarized below with respect to the drive structure of the cartridge to be noted.

The relationship between the driven side and the driven side in the present embodiment when the cartridge is attached / detached is that the first drive system for driving the photosensitive drum 1 and the developing sleeve 12 which is a main component of the developing unit 10 are used. A second drive system that rotates and endless coil springs 31 and 3 that circulate and convey toner;
As described above, the driven gears (L #, H #) are provided in the respective driven parts in the fourth driving system for driving the agitator 23 of the toner tank 20 and the driving means 25 for driving the toner tank 1a. As means for facilitating the meshing relationship between the driven gear and the driving gear disposed on the main body side by attaching and detaching, the driving gear is changed to a first gear (F1 #, K1 #).
And a second gear (F2 #, K2 #) , and the first gear (F1 #, K1 #) and a second gear (F2 #, K2 #) .
#) Is coaxial and rotatable by the structure as described above
Supported by the support means for supporting the first gear (F1
# 1, K1 #) and the second gear (F2 #, K2 #) are coaxial cores and are relatively rotatable by a predetermined angle (F1 # a, F1).
#B, F2 # a, F2 # b) , the rotation of which in the first gear (F1 #, K1 #) for transmitting power to the gear meshing with the driven gear (L #, H #) on one side. In the driven gear (L #, H #) on the other side, the concave portion and the convex portion are formed at the point symmetrical positions in the direction, and the concave portion and the convex portion are similarly formed at the point symmetrical position in the rotational direction in the concave portion. Second gear meshing
(F2 #, K2 #) are inserted and fitted so as to be relatively rotatable by a predetermined angle, and the first gear (F1 #, K1 #)
And the second gears (F2 #, K2 #) are provided with a first torque to urge each other to rotate and receive a rotational force with a second torque in a direction opposite to that of the first torque. As the urging means (FS, KS) , a compression spring is disposed in the common recess, and the first locking means (F1 #) which stops rotating while being rotationally urged by the first torque. b,
F2 # b) (K1 # b, K2 # b) , each of which is provided with a convex portion so as to maintain the initial state in which both of the convex portions are urged to rotate in one direction and come into contact with each other and stop. , The first
From the gear (F1 #, K1 #) to the second gear (F2 #, K2
#) Rotates the driven gear within a short time.
(L #, H #) and a second gear having a rotational load
(F2 #, K2 #) first gear (F1 #, K1 #) is compressed compression spring while stopped only rotates, the first gear in a state of being the rotated by the second torque (F1 # , K1 #)
And the second gear (F2 #, K2 #) abuts and stops
Locking means (F1 # a, F2 # a) (K1 # a, K2 #
b) a second convex portion and a second gear (F2 #, K2 ) formed at point-symmetric positions of the first gear (F1 #, K1 #) arranged as
The second convex portions formed at the point symmetric positions of #) are in contact with each other,
By rotating the second gear (F2 #, K2 #) , the driven gear
(L #, H #) , and the first gear
(F1 #, K1 #) is rotated to drive the second gear (F2
#, K2 #) via the driven gear (L #, and the rotary drive stops after driving the H #), when taken out of the cartridge, a second gear (F2 disposed together disengageably positions
#, K2 #) and the driven gears (L #, H #) are easily disengaged from each other, the rotational drive load of the second gear (F2 #, K2 #) is released, and the compression spring is extended to expand the second gear (F2 #, K2 #) . 2 gear
(F2 #, K2 #) is rotated to reach the initial state,
On the other hand, if the cartridge is mounted in the initial state, the second gear (F2 #, K2 #) and the driven gear (L #,
H #) in the meshing state, the driven gears (L #, H #) are driven in a direction opposite to the normal rotation direction of the second gear, that is, against the extension force of the compression spring by the driven rotation load. The second gear (F2 #, K2 #) is mounted by rotating the gear by a predetermined angle in the set direction, the cartridge can be easily attached and detached without difficulty, and the cartridge is driven when attaching / detaching the cartridge. As for the relationship between the gear on the drive side and the gear on the drive side, this embodiment does not constitute a complicated structure as disclosed in Japanese Patent Laid-Open Publication No. 1-222270, and has a simple structure as described above. Can be configured.

In the present embodiment, the above-mentioned driving mechanism includes a first driving system for driving the photosensitive drum 1, a second driving system for rotating and driving the developing sleeve 12 which is a main component of the developing unit 10, A preferred example is shown in which the driving means 25 for driving the endless coil springs 31 and 31a for circulating and conveying and the fourth driving system for rotating and driving the agitator 23 of the toner tank 20 are used. Instead of the condition, in a department where the driving load on the driven side is light, it may be deleted and the system may simply be configured as a system disconnection between gears.

In this embodiment, the detailed description has been given of the gear structure on the driving side. However, the present invention is not limited to the above detailed structure, and the second gear (F2 #, K2 #)
And a first gear (F1 #, K1 #) is supported by a support means for rotatably supporting and coaxially, the first gear
(F1 #, K1 #) and the second gear (F2 #, K2 #) is relatively predetermined angle component pivotable means coaxially (F1 #
a, F1 # b, F2 # a, F2 # b) and the first gear (F
1 #, K1 #) and the second gear (F2 #, K2 #) are applied with a first torque to urge each other to rotate and receive rotational power with a second torque opposite to the first torque. Rotating biasing means (FS, KS) to be rotated and first locking means (F1 # b, F2 # b) (K1 #) to stop rotating while being rotationally biased by the first torque. b, K2 # b) ,
In the state where the first gear (F1 #, K1) is rotated by the second torque,
1 #) and the second gear (F2 #, K2 #) are brought into contact with each other and stopped by the second locking means (F1 # a, F2 # a) (K1 # a, K
If 2 # b) is configured, the above functions and effects are exhibited.

[0143]

As described above, the image forming apparatus according to the present invention is a detachable image forming apparatus equipped with a driven gear and having a driven portion which is driven to rotate, and meshes with the driven gear. A second gear that is driven to rotate, a first gear that transmits drive to the second gear, support means that supports the second gear and the first gear coaxially and rotatably, and that the first gear and the second gear are coaxial. A means capable of relatively rotating by a predetermined angle with the core, a rotation urging means for applying a predetermined torque to the first gear and the second gear to thereby urge the first gear and the second gear to rotate relative to each other; First locking means that stops rotating in a state of being urged, and first and second gears are brought into contact with the first gear or the second gear being rotated against the rotating urging means. And a second locking means for stopping the driven gear by rotating the driven gear from the first gear via the second gear. The first gear and the second gear are arranged at positions where the driven gear can be disengaged when the cartridge is disengaged. After driving the driven gear via the second gear by rotating the first gear, the rotation is stopped and the cartridge is taken out. When the cartridge is taken out, the second gear and the driven gear disposed at positions where the system can be disengaged from each other become The meshing is forcibly disengaged, the rotational drive load of the second gear is released, and the rotation urging means rotates the second gear to reach the initial state stopped by the first locking means,
On the other hand, if the cartridge is mounted in this initial state, the driven gear is rotated in the opposite direction to the normal rotation direction of the second gear by the driven driving load in the process in which the second gear and the driven gear are engaged with each other. The second gear is mounted by rotating the second gear by a predetermined angle in the direction opposite to the urging force of the rotation urging means, and the mounting and dismounting of the cartridge is reasonably easy and easy. As for the relationship between the driven gear and the driven gear in the present invention, the present invention can be configured with a simple structure as described above without forming a complicated structure. Yes,
This is useful for a miniaturized configuration and an inexpensive configuration, and the practical effect of the present invention is extremely large.

[Brief description of the drawings]

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

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

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

FIG. 4 shows a first embodiment of the cartridge according to the present invention.
Sectional drawing of the important section on the left side of FIG.

FIG. 5 shows a second embodiment of the cartridge according to the present invention.
Sectional drawing of the important section on the left side of FIG.

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

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

FIG. 8 shows a first embodiment of the image forming apparatus according to the present invention.
FIG.

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

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

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

FIG. 12 is a cross-sectional view of a main part of the upper part showing one embodiment of the cartridge of the present invention.

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

[Explanation of symbols]

Reference Signs List 1 photosensitive drum 2 charging roller 5, 5A support member 7, 7A support pin 8, 8A spring 10 developing unit 12 developing sleeve 13 supply roller 17 cartridge upper case 18 cartridge lower case 20 toner tank 30, 30a toner transport unit 31, 31a coil Spring 40 Exposure unit 42 Exposure unit base 42a, 64a, 71a Positioning unit 50 Control unit 60 Fixing unit 64 Fixing base 70 Paper supply unit 71 Sheet material transport base 72 Paper supply tray 73 Paper supply roller 80 Transfer unit 81 Transfer roller 90 Cleaner part 92 cleaning blade 100 main chassis 100a (as positioning portions) protruding portion 100c first surface 100d second surface 100e third 101 wheel surface 100f coupling part row first receiving 102b, 102e, 101c, 101e support means 1 tumbler arm CS, FS, KS compression spring D # a first circumferential portion E # a second circumferential portion 103 drives the motor L #, H # driven gear F1 #, K1 # first gear F2 #, K2 # a 2 gears F1 # a, F1 # b, F2 # a, F2 # b pivotable
Means FS, KS rotation urging means F1 # b, F2 # b first locking means K1 # b, K2 # b first locking means F1 # a, F2 # a second locking means K1 # a, K2 # b Second locking means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-230173 (JP, A) JP-A-4-300438 (JP, A) JP-A-2-177943 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G03G 15/08 G03G 15/00 G03G 21/00 F16H 1/00

Claims (2)

(57) [Claims] 1. An image forming apparatus comprising a driven portion equipped with driven gears (L #, H #) and having a driven portion that is rotatably driven, wherein the driven gears (L #, H #) are provided. second gear (F2 #, K2 #) that rotates in mesh with the a, the second gear (F2 #, K2 #) first formic <br/> ya for drive transmission to (F1 #, K1 #) and, Second gear (F2 #, K2 #) and first gear (F1 #, K2 #)
1 #) coaxially and rotatably supported by supporting means (10
2b, 101c) (102e, 101e) , the first gear (F1 #, K1 #), and the second gear (F2 #,
K2 #) is relatively predetermined angle component pivotable means coaxially (F1 # a, and F1 # b, F2 # a, F2 # b), said first gear (F1 #, K1 #) and The second gear (F2 #,
K2 #) to a predetermined impart torque is rotationally biased together <br/> Ru rotation urging means (FS, and KS), the predetermined times in a state of being rotationally biased together by a torque The first locking means (F1 # b, F2 # b) that stops moving (K
1 # b, K2 # b) and the first gear against the rotation urging means (FS, KS).
(F1 #, K1 #) or the second gear (F2 #, K2
# 1) and the first gear (F1 #, K1 #)
And the second gear (F2 #, K2 #) abuts and stops
Locking means (F1 # a, F2 # a) (K1 # a, K2 #
b) and the second gear (F2 ) from the first gear (F1 #, K1 #) .
#, K2 #) , when the driven gears (L #, H #) are rotationally driven, the second locking means (F1 # a, F2 #)
a) A structure in which rotational drive is transmitted by (K1 # a, K2 # b) and the first gear (F1 #, K2
1 #) and the second gear (F2 #, K2 #) are arranged at positions where the driven gear can be disengaged when the cartridge is disengaged. 2. The apparatus according to claim 1, wherein said driven gears (L #, H #) are provided in a driven portion of said photosensitive member or a developing portion for developing toner on a latent image of said photosensitive member. 2. The image forming apparatus according to 1.