JP3386540B2 - 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 electrostatic recording type image forming apparatus applied to a printer, a copying machine or the like.
The present invention relates to an image forming apparatus using a drum-shaped photoconductor that is attachable to and detachable from an apparatus body.

[0002]

2. Description of the Related Art Conventionally, various devices have been tried for a mechanism or method for separating and replacing only a photosensitive drum from an image forming unit such as a charging unit or a developing unit. It is also widely practiced to wrap a light-shielding paper to protect a new photoconductor drum before attachment from light fatigue.

Further, as a technique of this kind, there is a conventional technique of Japanese Patent Laid-Open No.
54-113344, Japanese Patent Laid-Open No. 63-118759, Japanese Utility Model Laid-Open No. 63
-74641 and JP-A-60-114893.

Japanese Unexamined Patent Publication No. 54-113344 discloses a technique in which the surface of a photoconductor is covered with a protective sheet, the photoconductor is attached to the main body of the apparatus, and then the protective sheet is removed.

In Japanese Laid-Open Patent Publication No. 63-118759, when the photosensitive drum is mounted on the main body of the apparatus together with the support in a state where the protective sheet is rewound, the protective sheet is positioned at the sheet feeding section, and the sheet feeding section is A technique of removing the protective sheet by driving is described.

Japanese Utility Model Laid-Open No. 63-74641 discloses a construction in which a protective sheet is pulled to peel it from the surface of the photosensitive member.

In Japanese Patent Laid-Open No. 60-114893, a part of the circumferential surface of the protective sheet is opened and the protective sheet is removed in the direction of the center of the photosensitive drum so that the photosensitive drum can be attached and detached. Meanwhile, a technique for facilitating the removal of the light-shielding paper is described.

[0008]

The photoconductors described in JP-A-63-118759 and JP-A-63-74641 are all replaceable integrally with other image forming units. However, since the photosensitive drum has a relatively long life, it is possible to reduce the running cost by exchanging it separately from other image forming units.

Particularly, in the image forming apparatus described in Japanese Patent Laid-Open No. 63-118759, when the light-shielding paper is put into the main body of the apparatus, the presence or absence of the light-shielding paper cannot be detected unless the photosensitive drum is driven for a predetermined time. Therefore, if the shading paper touches the charging wire of the charger during this period, there is a risk that the shading paper will ignite. Further, when the photoconductor drum and the developing roller are in contact with each other and are driven with a linear velocity difference, the light-shielding paper may be wrinkled or the light-shielding paper may be broken.

According to the image forming apparatus disclosed in Japanese Utility Model Laid-Open No. 63-74641, since the other image forming unit presses the overlapping portion of the light-shielding paper, the photosensitive drum alone is replaced. This is not suitable for a configuration in which there is no means for pressing the light shielding paper as in the case.

Further, according to Japanese Patent Laid-Open No. 60-114893, when a part of the image forming unit above the photosensitive drum is opened in order to improve the exchangeability, the bearing of the photosensitive drum shaft originally has a void. The feature is that it rolls in the inside (the support part becomes rotatable). However, since the bearing is originally fixed to the bearing with a gap by a predetermined restricting member, the photosensitive drum is likely to vibrate, and the image is liable to have jitter or the like.

Further, by exchanging the photosensitive drum independently, there is a possibility that the photosensitive drum may be forgotten to be set or the light shielding paper may be forgotten to be removed.

The present invention has been made in view of the above problems, and an object of the present invention is to reliably remove the light-shielding paper and set the photosensitive drum.

[0014]

In order to achieve the above object, the present invention provides a photosensitive drum and a photosensitive drum.
The image forming apparatus of an electrostatic recording method having a detachable photosensitive drum unit with respect to become the apparatus body from the frame supporting, through holes that are covered by the wound backing paper for the protection of the photosensitive drum surface Of the frame
Partly formed and rotatably arranged near this through hole
A filler and a support for rotatably supporting the filler,
And outputs a signal according to the rotational position of the filler
The detection means is provided in the main body of the device, and the detection means
1st time when it is in contact with the light-shielding paper that covers the hole
The moving position and the through hole is opened to the edge of the through hole.
No second rotation position when in contact with the through hole
Said filler in at least three stages with a third pivot position in the case
It is characterized in that a detection signal is output in correspondence with the rotation position of the user.

Further, the detecting means is a photo sensor.

Further, the detecting means is moved to the first rotation position.
It is characterized in that a control means for prohibiting the printing operation is provided when it is detected that the filler is positioned .

Further, the detecting means is located at the first rotation position.
When the serial filler has detected that the position, characterized by comprising a control means for releasing the connection of the sense <br/> light drum and the driving source.

[0018]

[0019]

With respect to the image forming apparatus configured as described above,
If the light-shielding paper remains, the filler moves to the first rotation position.
The photoconductor drum when the shading paper is removed.
If the unit is installed, the filler
The photoconductor drum unit is not installed.
If not, the filler is in the third pivoted position
By detecting the rotation position from the
Do not forget to remove or remove the photosensitive drum unit
It can be prevented .

Further, by using a photo sensor as the detecting means, it is possible to detect the remaining of the light-shielding paper by utilizing the original characteristic of the light-shielding paper that blocks light.

When detecting the remaining of the light-shielding paper,
By prohibiting the printing operation and informing the user to remove the shading paper, the shading paper can be removed in advance.

Further, when the detecting means detects the remaining of the light-shielding paper, the transmission of the driving force to the photosensitive drum is released, so that the rotational load applied to the photosensitive drum can be reduced .

[0023]

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an external view showing a combined state of main units according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the inside of FIG. In FIG. 1, 1 is a photosensitive drum unit, 2
Is a developing unit, and 3 is a toner tank cleaning unit. Further, in FIG. 2, 4 is a photosensitive drum,
5 is a developing roller, 6 is an intermediate roller, 7 is a replenishing agitator, 8 is a thinning blade, 9 is a toner replenishing port, 10 is a developing hopper, 11 is a toner tank, 12 is a toner agitator, 13
Is a toner supply port, 14 is a toner supply port 13 shutter, 15 is a waste toner tank, 16 is a cleaning blade, 17 is a waste toner recovery roller, 18 is a waste toner recovery port, 19 is a waste toner recovery port 18 shutter, and 20 is a waste toner recovery port. Is a static eliminator, and 21 is a charging roller.

As shown in FIG. 2, the photosensitive drum unit 1 includes a photosensitive drum 4. Also the developing unit 2
Is a developing roller 5, an intermediate roller 6, a replenishing agitator 7,
A thin layer blade 8, a toner supply port 9, and a developing hopper 10 are provided. Further, the toner tank / cleaning unit 3 includes a toner tank 11, a toner agitator 12, a toner supply port 13, a shutter 14, a waste toner tank 15, a cleaning blade 16, a waste toner collecting roller 17, a waste toner collecting port 1
It is provided with 8, a shutter 19, a static eliminator 20, and a charging roller 21.

As shown in FIG. 1, when the photosensitive drum unit 1 and the toner tank / cleaning unit 3 are mounted on the developing unit 2, the intermediate roller 6 and the cleaning blade 16 are attached to the photosensitive drum 4 as shown in FIG. The waste toner collecting roller 17 and the charging roller 21 come into contact with each other. At the same time, the toner tank 11 is arranged in the developing hopper 10, and the toner supply port 9 and the toner supply port 13 face each other.

The new toner in the toner tank 11 is carried to the toner supply port 13 by the rotation of the toner agitator 12 and supplied into the developing unit 2 from the toner supply port 9. In the developing unit 2, the new toner is carried to the developing roller 5 by the rotation of the replenishing agitator 7, and the new toner adsorbed to the developing roller 5 is thinned by the thinning blade 8 and further exposed through the intermediate roller 6. It adheres to the electrostatic latent image formed on the body drum 4. The toner remaining on the photosensitive drum 4 in the image forming process is stored in the waste toner tank 15 from the waste toner collecting port 18 by the cleaning blade 16 and the waste toner collecting roller 17. Since the image forming process is known, the description thereof is omitted.

FIG. 3 is an exploded perspective view showing the structure of the photosensitive drum unit and the mounting mechanism to the developing unit.
Is a U-shaped frame for supporting the photosensitive drum 4, 23 is a handle for attaching and detaching the frame 22 to the developing unit 2, 24 is a mounting hole provided in the center of the side surface of the frame 22, and 25 is a mounting hole 24.
A projection that is erected on the side of the frame 22 and at the end of the side of the frame 22,
Reference numeral 26 is a support shaft of the photosensitive drum 4, 27 is a lock lever for fixing the frame 22 to the developing unit 2, 28 is a spring, and 29 is a drive gear installed on one side surface of the photosensitive drum 4. Further, 30 is a frame on which the developing roller 5 and the like are mounted, 31 is a side plate of the frame 30, 32 is a bearing portion of a support shaft 26 formed in a concave shape with respect to an upper portion of the side plate 31, and 33 is a side plate.
31 shows a protrusion standing on the surface and below the bearing 32.

The support shaft 26 is a thick shaft 26a fitted in the mounting hole 24.
A thin shaft 26b that supports the photosensitive drum 4, an engaging shaft 26c that engages with the bearing 32, and a fixing plate 26d that fixes the frame 22 to the frame 22. Also, the thin shaft 26b, the thick shaft 26a,
The engagement shaft 26c is coaxial in this order, and the fixed plate 26d is provided between the thick shaft 26a and the engagement shaft 26c.

The lock lever 27 includes a plate-shaped turning body 27a,
A fitting hole 27b provided in the central portion of the rotating body 27a for loosely fitting the engaging shaft 26c of the support shaft 26, an operation lever 27c provided at one end of the rotating body 27a, and an upright position at one end of the rotating body 27a. Protrusion 27
d and a hook portion 27e formed on the other end of the rotating body 27a.

Then, the photosensitive drum 4 is arranged between both side surfaces of the frame 22, and the support shafts 26, 26 are fitted into the mounting holes 24, 24 to support the photosensitive drum 4, and the support shaft 26 is free to move. The photoconductor drum unit 1 is configured by installing the spring 28 between the protrusion 27d of the fitted lock lever 27 and the protrusion 25 of the frame 22.

In the photosensitive drum unit 1 thus constructed, the engaging shaft 26c is placed on the bearing portion 32 of the developing unit 2, and the hook portion 27e of the lock lever 27 and the protrusion 33 are engaged with each other. , Is attached to the developing unit 2. At this time, the frame 22 is rotated by the tension of the spring 28, and the photosensitive drum 4 comes into contact with the intermediate roller 6 under a predetermined pressure.

A through hole 23a is formed in the center of the surface of the handle 23 of the frame 22, and the through hole 23a is involved in the on / off operation of the sensor described later.

FIG. 4 is an internal side view showing the configuration of the photoconductor drum unit at the time of shipment of a new product.
Is a drawing member, and 36 is an adhesive tape. When shipping the photoconductor drum unit 1 as a new product, as shown in FIG.
Is wrapped around the photosensitive drum 4,
The pull-out member 35 attached to one end of 34 is fixed to the handle 23 by the adhesive tape 36. The other end of the light-shielding paper 34 is adhered to the inner surface of the light-shielding paper 34 while the light-shielding paper 34 is wound around the photosensitive drum 4. The adhesive force at this time is such that it can be easily peeled off when tension is applied to the light shielding paper 34.

FIG. 5 is an internal structural view showing a state in which the main unit is attached to the main body of the image forming apparatus, 37 is a cover of the main body of the image forming apparatus, 38 is a paper feeding cassette, 39 is a paper feeding roller, 40
Is a sensor for detecting the presence or absence of the light-shielding paper 34, 41 is a discharge roller,
Reference numeral 42 denotes a paper discharge tray.

To replace the photosensitive drum 4, first open the cover 37, remove the toner tank cleaning unit 3 from the developing unit 2, remove the photosensitive drum unit 1,
The new photosensitive drum unit 1 is attached to the developing unit 2. Next, after removing the adhesive tape 36 from the pull-out member 35 shown in FIG. 4 and removing the light-shielding paper 34 by pulling on the pull-out member 35, the toner tank cleaning unit 3 is attached and the cover 37 of the main body is closed. Complete.

FIG. 6 is a perspective view showing the structure of the sensor.
Reference numeral 40a denotes a filler, 40b denotes a support member that rotatably supports the filler 40a, and 40c and 40d denote reflection type photosensors attached to the support member 40b. Two photosensors 40c and 40d are attached to the support body 40b with the reflected light blocking portion 40e formed at the other end of the filler 40a interposed therebetween. The filler 40a has the reflected light blocking portion 40e attached to the photosensor 40d. It is normally urged in the X direction in the figure so as to move. When the photosensitive drum unit 1 is installed in the main body of the apparatus, the filler 40a
The sensor 40 is installed in the main body of the apparatus such that one end of the sensor 40 is located in the through hole 23a.

FIG. 7 is an explanatory view showing the operation of the sensor 40 when the photosensitive drum unit 1 is mounted on the main body of the apparatus.
When the photoconductor drum unit 1 is not attached to the main body of the apparatus, as shown in FIG.
Is covered by the reflected light blocking portion 40e of the filler 40a, and the reflected light entering the photosensor 40d is blocked.

When a new photoconductor drum unit 1 is mounted from this state, as shown in FIG. 7B, the shading paper 34 comes into contact with one end of the filler 40a, and as the photoconductor drum unit 1 is mounted, the filler 40a is filled. Is pushed down, the photo sensor 40d is opened, and the other photo sensor 40c is covered by the reflected light blocking unit 40e.

Further, by removing the light shielding paper 34, the through hole
The opening 23a is opened, and one end of the filler 40a moves in the X direction in the drawing to come into contact with the edge of the through hole 23a. At that time, the reflected light blocking unit 40e is positioned between the photosensors 40c and 40d.

By the operation of the sensor 40 as described above, if the photosensitive drum unit 1 is attached to the apparatus main body,
Since the photo sensor 40d detects the reflected light, it can be determined whether or not the photoconductor drum unit 1 is set. Further, when the light-shielding paper 34 remains, there is no output from the photosensor 40c, and when the light-shielding paper 34 is removed, the photosensor 40c detects the reflected light and outputs the detection signal. It is possible to determine whether or not the light shielding paper 34 remains.

FIG. 8 is a perspective view showing a drive system of the photosensitive drum unit. 43 is a frame, 44 is a drive motor, 45 is a transmission gear attached to the drive motor 44, and 46 is a first gear meshing with the drive gear 29. , 47 is a second gear that meshes with the transmission gear 45, 48 is an electromagnetic clutch that connects or disconnects the second gear 47 and the first gear 46, and 49 is the first gear 46, the second gear 47,
A support shaft for coaxially supporting the electromagnetic clutch 48 is shown. A drive motor 44 and a support shaft 49 are installed in the frame 43, and a transmission gear 45 and a second gear 47 mesh with each other inside the frame 43. The frame 43 is the first gear 46 in the main body of the device.
And the drive gear 29 are installed at a position where they can mesh with each other.

FIG. 9 is a block diagram showing a control circuit for performing drive control before starting the printing operation, and FIG. 10 is a flow chart showing a drive control process before starting the printing operation. Figure 9
In the figure, 50 is an open / close switch for detecting the open / closed state of the cover 37, 51 is a display unit, and 52 is a CPU (central processing unit).

Based on the outputs from the photosensors 40c and 40d and the open / close switch 50, the CPU 52 determines the presence or absence of the photosensitive drum 4 or the light-shielding paper 34, the open / closed state of the cover 37, and operates the electromagnetic clutch 48. Decide

Next, the operation before starting the printing operation will be described with reference to FIG.
Will be described with reference to. When the power is turned on (S1),
The CPU 52 detects the state of the open / close switch 50 of the cover 37,
If it is off (NO in (S2)), the display section 51 displays "Cover OPE
Notify the user by displaying "N" (S3). Further, the CPU 52 causes the charging roller 21 and the developing roller 5 (see FIG. 2).
Prohibits the start of operations such as to disable printing (S12), disconnects the first gear 46 and electromagnetic clutch 48 (S13), and covers
Wait until 37 is closed. When the cover 37 is closed, the state of the open / close switch 50 is detected again (return to S2). If it is on (YES in (S2)), then the state of the photo sensor 40d is detected (S4).

If the state of the photo sensor 40d is off ((S
4) YES), the display unit 51 displays "No photoconductor drum" (S5) to inform the user. Then, the CPU 52 further disables the printing operation (S12), disconnects the first gear 46 and the electromagnetic clutch 48 (S13), and waits until the photosensitive drum 4 is mounted. When the photosensitive drum 4 is mounted, the state of the open / close switch 50 is detected again (return to S2). If it is on (NO in (S4)), the CPU 52 determines that the photosensitive drum 4 is mounted (S6), and then detects the state of the photo sensor 40c (S7).

If the state of the photo sensor 40c is off ((S
7) YES), and display section 51 displays "Shadow paper remains" (S
8) Notify the user. Then, the CPU 52 further disables the printing operation (S12) and turns off the electromagnetic clutch 48.
(S13) The first gear 46 and the electromagnetic clutch 48 are disengaged, and the light-shielding paper 34 is put on standby. When the shading paper 34 is removed, the state of the open / close switch 50 is detected again (return to S2). If it is ON (NO in (S7)), the CPU 52 enables the printing operation (S10), connects the first gear 46 and the electromagnetic clutch 48 (S10), and rotates the drive motor 44 to start the printing operation ( S11).

By the way, when the user replaces the photosensitive drum unit 1, as an abnormal situation that an unskilled user can cause, the following can be considered.

1. Forgetting to set the photoconductor drum unit 1 and closing the cover 37.

2. Forgetting to remove the light-shielding paper 34 on the photoconductor drum 4 and closing the cover 37.

3. Do not set the toner tank cleaning unit 3 and close the cover 37.

According to the present embodiment, since the presence or absence of the photosensitive drum unit 1 and the remaining of the light shielding paper 34 can be detected by the sensor 40, the above-mentioned items 1 and 2 can be solved, and the printing operation is erroneously performed. It is possible to prevent the risk of being lost.

[0054]

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

[0055] According to the first aspect, wherein, even wearing the photosensitive drum unit left to remain the backing paper in the apparatus main body, since the remaining backing paper by the detecting means is detected, the backing paper It is possible to prevent forgetting to remove
Ri, Rukoto damage the internal device where a malfunction is prevented. In addition, the detection means simultaneously detects the photosensitive drum unit.
The number of parts is increased by having the function to detect the presence or absence of
Do not forget to install the photoconductor drum unit without adding
It can be resolved. Also, the filler is in the second rotation position.
When it is moved to the photosensitive drum unit,
To know that the knit is properly worn
It

According to the second aspect of the present invention, by using the photo sensor as the detection means, it is possible to detect the remaining of the light-shielding paper by utilizing the original characteristic of the light-shielding paper that blocks light. You don't have to increase your score.

According to the third aspect of the present invention, when the remaining light-shielding paper is detected, the print operation is prohibited and the user is informed to remove the light-shielding paper. There is no danger of going there and safety can be secured.

According to the fourth aspect of the invention, when the detecting means detects the remaining of the light-shielding paper, the transmission of the driving force to the photosensitive drum is released, so that the rotation of the photosensitive drum is prevented.
Since the rolling load can be reduced, the pulling force required when removing the light-shielding paper can be reduced, and the influence on the surface of the photosensitive drum can be reduced.

[0059]

[Brief description of drawings]

FIG. 1 is an external view showing a combined state of main units according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing the inside of FIG.

FIG. 3 is an exploded perspective view showing a configuration of a photosensitive drum unit and a mounting mechanism to a developing unit.

FIG. 4 is an internal side view showing the configuration of a photoconductor drum unit at the time of new shipment.

FIG. 5 is an internal configuration diagram showing a state in which a main unit is attached to the image forming apparatus main body.

FIG. 6 is a perspective view showing the structure of a sensor.

FIG. 7 is an explanatory diagram showing the operation of the sensor when the photosensitive drum unit is attached to the apparatus main body.

FIG. 8 is a perspective view showing a drive system of a photosensitive drum unit.

FIG. 9 is a block diagram showing a control circuit for performing drive control before starting a printing operation.

FIG. 10 is a flowchart showing a drive control process before starting a printing operation.

[Explanation of symbols]

1 ... Photosensitive drum unit, 2 ... Developing unit, 3
... toner tank / cleaning unit, 4 ... photosensitive drum, 5 ... developing roller, 6 ... intermediate roller, 7 ... supplementing agitator, 8 ... thinning blade, 9 ... toner replenishing port, 10 ... developing hopper, 11 ... toner tank , 12 ...
Toner agitator, 13 ... Toner supply port, 14, 19 ... Shutter, 15 ... Waste toner tank, 16 ... Cleaning blade, 17 ... Waste toner collecting roller, 18 ... Waste toner collecting port, 20 ... Eliminating device, 21 ... Charging roller, 22, 30, 43
… Frame, 23… Handle, 24… Mounting hole, 25, 27d, 3
3 ... Protrusion, 26, 49 ... Support shaft, 26a ... Thick shaft, 26b ... Thin shaft, 26c ... Engaging shaft, 26d ... Fixing plate, 27 ... Lock lever, 27a ... Rotating body, 27b ... Fitting hole, 27c ... Operation Lever, 27e ... Hook part, 28 ... Spring, 29 ... Drive gear, 31 ... Side plate, 32 ... Bearing part, 34 ... Shading paper, 35
Drawer, 36 ... Adhesive tape, 37 ... Cover, 38 ... Paper feed cassette, 39 ... Paper feed roller, 40 ... Sensor, 40a ...
Filler, 40b ... Support, 40c, 40d ... Reflective photo sensor, 40e ... Reflected light blocking part, 41 ... Paper ejection roller, 4
2 ... Paper output tray, 44 ... Drive motor, 45 ... Transmission gear,
46 ... 1st gear, 47 ... 2nd gear, 48 ... Electromagnetic clutch, 50 ... Open / close switch, 51 ... Display, 52 ... CPU
(Central processing unit).

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-323842 (JP, A) JP-A-5-201565 (JP, A) JP-A-2-291345 (JP, A) JP-A-59- 195263 (JP, A) JP-A-3-261986 (JP, A) Actually opened 60-60765 (JP, U) Actually opened 4-24771 (JP, U) Actually opened 62-12170 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 21/00 370-540 G03G 21/14 G03G 21/00 350 G03G 15/00 550

Claims (4)

(57) [Claims] 1. A photosensitive drum and the photosensitive drum
The image forming apparatus of an electrostatic recording method having a detachable photosensitive drum unit with respect to become the apparatus body from the frame supporting, through holes that are covered by the wound backing paper for the protection of the photosensitive drum surface Of the frame
Partly formed and rotatably arranged near this through hole
A filler and a support for rotatably supporting the filler,
And outputs a signal according to the rotational position of the filler
The detection means is provided in the main body of the device, and the detection means
1st time when it is in contact with the light-shielding paper that covers the hole
The moving position and the through hole is opened to the edge of the through hole.
No second rotation position when in contact with the through hole
Said filler in at least three stages with a third pivot position in the case
An image forming apparatus which outputs a detection signal corresponding to a rotational position of the image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the detecting means is a photo sensor. Wherein said detecting means, said full the first pivot position
2. The image forming apparatus according to claim 1, further comprising control means for prohibiting a printing operation when it is detected that the wheel is located . 4. The detecting means is arranged to move the flap to a first rotation position.
2. The image forming apparatus according to claim 1, further comprising control means for disconnecting the connection between the photosensitive drum and the drive source when it is detected that the wheel is positioned .