JP2503319Y2 - Image forming unit detection device - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an image forming apparatus such as a printer or a copying machine, and more particularly to an image forming unit detecting apparatus for detecting the time to replace an image forming unit.

[Prior Art and its Problems] Conventionally, a photosensitive drum, a charger, a cleaner, a developing device, and the like are used as one image forming unit, and after performing a predetermined number of times of image formation, this image forming unit is replaced with a new unit. An image forming apparatus configured to do so is known,
In this type, the number of image formations or the number of prints is measured by a counter or the like, and when the image formation of a predetermined number of times is finished, the fact that the life of the image forming unit has expired is displayed on the display section.

FIG. 9 is a schematic cross-sectional view of a part of the conventional image forming unit as described above, 1 is a part of the image forming unit, 2 is a casing of the image forming unit, and 3 has a drum gear 3a. Photoconductor drum, 4 is a charger, 5 is a cleaner blade, 6 is an idle gear meshing with the drum gear 3a, 7 is an actuator gear fixed to a shaft 7b having a male screw portion 7a and meshing with the idle gear 6, Reference numeral 8 denotes a guide slot 8a in the upper portion, a not-shown convex portion in a part of the lower portion, and a female screw portion 8b screwed to the male screw portion 7a.
A reset actuator 9 having a guide 9 fixed to the casing 2 and slidably engaged with the guide slot 8a, and a guide 10 fixedly mounted in the main body of the image forming apparatus. 8 is a micro switch which has a pin plunger 10a which comes into contact with the convex portion 8 and which resets the counting circuit of the number of prints of the image forming unit.

When the image forming unit 2 is attached to the image forming apparatus at the time of shipment from the factory, that is, in a new state, the protrusion (not shown) of the reset actuator 8 causes the pin plunger 10a.
Press to switch the on / off state of the microswitch 10 / reset the counting circuit for the number of printed images.

When the photosensitive drum 3 rotates and the first printing of the first sheet is performed, this rotation is transmitted to the actuator gear 7 via the idle gear 6, and the male screw portion 7a is integrated with the actuator gear 7. Rotate. The reset actuator 8 is screwed to the male screw portion 7a by the female screw portion 8b, but it does not rotate because the guide slot 8a is slidably connected to the guide 9,
Linearly slides along the axial direction of the shaft 7b. By this sliding operation, the convex portion that is in contact with the pin plunger 10a is released, the on / off state of the microswitch 10 is switched, and the counting circuit starts counting. Since the male screw portion 7a is released from the pressing force on the pin plunger 10a by the convex portion, an unillustrated shaft portion having an outer diameter slightly smaller than the root diameter of the male screw portion 7a is connected to the male screw portion 7a. Since the shaft portion turns around in the female screw portion 8b of the reset actuator 8, the axial movement due to the screwing does not occur thereafter.

The reset actuator of the counting circuit of the conventional image forming unit as described above is used in a very good condition without any inconvenience when used by the user after being shipped from the factory.

However, according to the above-mentioned conventional technique, there are the following problems when assembling and adjusting at the factory.

That is, when assembling, the reset actuator 8
The shaft 7b is inserted through and screwed into the assembling, but the assembling work is complicated, and the photosensitive drum 3 may be unavoidably rotated during the production process due to adjustment or the like. Since the eater 8 moves along the axial direction, it is necessary to return the reset actuator 8 to the original position (the position where the convex portion can press the micro switch 10) again at the time of shipping. It is not preferable to rotate the photosensitive drum 3 in the reverse direction because it is assembled in a proper positional relationship with the surrounding arrangement members such as the cleaning blade 5, and therefore, the photosensitive drum 3 is rotated in the reverse direction to return the reset actuator 8 to the original position. I can't.
Therefore, in reality, with the reset actuator 8 incorporated in the image forming unit 1, the once moved actuator 8 can hardly be returned to the original state, and it has to be disassembled and reassembled again.

Therefore, the above-mentioned conventional technique has a problem that it takes an extremely large number of steps and time to perform the adjustment at the time of assembling, which increases the assembling cost.

[Purpose of device]

In view of the above-mentioned conventional drawbacks, the present invention makes it easy to assemble the actuator, and even if the photosensitive drum is rotated during adjustment, the moved actuator can be quickly set to a new state without disassembling the image forming unit. It is an object of the present invention to provide an image forming unit detection device that is made possible.

[Key points of device]

In order to achieve the above object, the present invention is provided in an image forming unit that includes an image forming element and is detachably attached to an image forming apparatus main body, and the unit is in a first position on a rotation shaft when not in use. In the image forming unit detection device equipped with a moving member that is mounted on the device body and is used when an image forming operation is performed and the moving member moves from the first position to the second position in the rotation axis direction, the moving member is It is characterized in that it has a flexible grip portion that can be mounted on a rotating shaft.

〔Example〕

 Hereinafter, the present invention will be described with reference to illustrated embodiments.

FIG. 1 is a schematic sectional view showing an essential part of an embodiment of the present invention, showing a state before the reset actuator is activated.

FIG. 2 is a schematic sectional view showing the operating state of FIG.

FIG. 3 is a schematic cross-sectional view taken along the line III-III in FIG.

4 (a) and 4 (b) are enlarged views of the main part of FIG.

FIG. 4 (c) is a cross-sectional view taken along the line VV in FIG. 4 (b).

FIG. 5 is a perspective view of FIG. 4 (b), and FIG. 6 is a perspective view showing another embodiment in FIG.

FIG. 7 is a schematic sectional view showing an outline of an image forming unit to which the embodiment of the present invention is applied, and FIG. 8 is a schematic sectional view showing an image forming apparatus incorporating the image forming unit shown in FIG. is there.

In FIG. 1, 11 is a photosensitive drum, 12 is a charger, and 13
Has a stopper 13a, 13b, a notch 13c, a cleaner blade 13d, a cleaner for collecting the waste toner, 14 is an actuator described later, 15 is the photosensitive drum 11, the charger 12, the cleaner 13, etc. are integrally assembled A part of the image forming unit is shown, and a whole sectional view is shown in FIG. 16
Has a detection arm 16a and a switch arm 16b, is pivotally attached to the main body of the image forming apparatus 17 by a shaft 16c, and is provided with a habit of rotating counterclockwise by a switch spring 16d. 9 shows a part of the image forming apparatus shown in FIG. Reference numeral 18 denotes a micro switch which has a pin plunger 18a with which the switch arm 16b can come into contact, is fixedly attached to the image forming apparatus 17, and resets the image forming processing number counting circuit by pushing the pin plunger 18a.

FIG. 2 is an explanatory view showing the operation of FIG. 1 and will be described later.

In FIG. 3, 11a is a drum gear that operates integrally with the photosensitive drum 11, 19 is a male screw portion 19a, a sliding portion 19b having a diameter equal to or slightly smaller than the root diameter of the male screw portion 19a, and the sliding portion. An actuator gear 19c that is fixed and meshes with the drum gear 11a, and a coil spring-shaped transfer coil that transfers waste toner
Actuator shaft with 19d.

In FIGS. 4 to 5, reference numeral 14 is a female screw portion 14a formed by forming only a part of a circumference capable of being screwed with the male screw portion 19a, flexible snap arms 14b, 14c, and a detent arm. 14d, an actuator having a protrusion 14e.

FIG. 6 shows another embodiment of the present invention, which will be described later.

In FIG. 7, reference numeral 20 denotes a toner box 20a containing toner, and an initial developer 20 formed by mixing toner and carrier.
A developer tank 20c for accommodating b, a developing device having a developing sleeve 20e for adjusting the toner layer thickness on the doctor blade 20d and adhering the toner carried on the peripheral surface to the photosensitive drum 11, as described in FIG. Is the photoconductor drum 11, charger 12,
The image forming unit is a single unit in which the cleaner 13, the developing device 20 and the like are replaceable, and the arrows indicate the rotation directions of the respective members.

In FIG. 8, 17 is an image forming apparatus, 21 is a sheet, 22 is a sheet conveying path through which one sheet 21 is conveyed and an arrow indicating the direction, and 23 is toner formed on the peripheral surface of the photosensitive drum 11. A transfer device for transferring the image onto the paper 21, 24 is a printing means such as a print head for forming an electrostatic latent image on the peripheral surface of the photoconductor drum 11, 25 is a fixing device for fixing the image on the paper 21, and 26 is Reference numeral 27 denotes a face-up tray on which the image is placed face up, and 27 is a face-up tray on which the image is placed face down.

In the image forming apparatus 17 shown in FIG. 8, the paper 21 is conveyed as shown by the arrow 22, and the toner image is transferred from the photoconductor drum 11 in the image forming unit 15 by the transfer device 23 to the fixing device.
The toner image is fixed by 25, and thereafter, the paper is discharged and stacked on the face-up tray 26 or the face-down tray 27 according to the selection made in advance.

The above-mentioned image forming apparatus 17 is of a type in which the image forming unit 15 is exchanged, and the image forming unit is exchanged for a new image forming unit because its life is exhausted after a predetermined number of uses.

The standard for replacement of the image forming unit 15 is based on the number of times of image formation that deteriorates the overall performance including deterioration of the photosensitive performance of the photosensitive drum 11, for example.
The predetermined operation amount of the members forming 15 is counted, and when the predetermined operation amount is reached, it is judged that the life has expired.

The circuit for performing this counting is reset when a new image forming unit 15 is attached to the image forming apparatus 17, and is counted every time image formation is performed thereafter.

This reset is performed by once pushing the pin plunger 18a of the microswitch 18 and then releasing it again.

As shown in FIG. 8, when a new image forming unit 15 is attached to the image forming apparatus 17, the protrusion 14e comes into contact with the detection arm 16a as shown in FIG. 1 and switches against the switch spring 16d. The switching lever 16 is rotated clockwise to release the pin plunger 18a and switch the connection of the micro switch 18. When the image forming operation is started and the photoconductor drum 11 rotates in FIG. 3 and the actuator shaft 19 is rotated by the engagement of the drum gear 11a and the actuator gear 19c, the male screw portion 19a of the actuator shaft 19 is screwed. The female screw portion 14a that is moving advances in the direction of the arrow shown in the figure and moves to the position 14 'shown by the chain double-dashed line. When the actuator shaft 19 rotates, the actuator 14 also tries to rotate together, but as shown in FIG. 1 and FIG.
Is prevented by the stopper 13b, and the stopper 13a also inhibits the corner portion of the actuator 14, so that it does not rotate. When the actuator 14 moves, the protrusion 14e shown in FIG. 1 moves out of the position that restrains the detection arm 16a, so the switch switching lever 16 is rotated counterclockwise by the urging of the switch spring 16d, and the second As shown in the figure, the plunger 18a is pushed to switch the micro switch 18.

As shown in FIG. 3, the actuator 14 has the female screw portion 14a at the sliding portion 19b and the male screw portion 19 at the position 14 '.
In this condition, the actuator shaft 1
Even if 9 rotates, it does not operate in the direction of the arrow and is stopped.

As shown in detail in FIGS. 4 (a), (b), (c) to FIG. 5, the actuator 14 and the actuator shaft 19 have only a partial portion of the entire circumference of the actuator 14. A female screw portion 14a is provided.
Engages with the male screw portion 19a of the actuator shaft 19. As shown in FIG. 4 (b), this screwing is held by the flexible snap arms 14b, 14c so that the male screw portion 19a does not come off, but when the actuator 14 is attached to or detached from the actuator shaft 19, As shown in FIG. 4 (a), the actuator 14 is pushed or pulled in the radial direction of the actuator shaft 19. In particular, the actuator 14 is
Even when the female screw portion 14a is moved from a to the sliding portion 19b and is not screwed with the male screw portion 19a, the snap arms 14b, 14
Although c grips the sliding portion 19b, the outer diameter dimension of the sliding portion 19b is smaller than the outer diameter dimension of the male screw portion 19a, and therefore the force for removing the sliding portion 19b may be small.

As shown in FIG. 8, when the image forming unit 15 is incorporated into the image forming apparatus 17 to form an image, the actuator 14 will have the male screw portion 19a of the actuator shaft 19 at the time when the first first image is formed. And move to the sliding part 19b,
Then, the counting circuit records and displays that the first image formation has been performed. This recorded data is obtained by removing the image forming unit 15 for maintenance such as processing of jammed paper,
Even if it is assembled, the detection arm 16a of the switch switching lever 16 is disengaged from the protrusion 14e of the actuator 14 and the pin plunger 18a is not pressed, so the counting circuit is not reset. And count.

When assembling and processing this image forming unit in the factory and performing the final inspection, the actuator 14 is of course the actuator shaft 19
It is assembled in a state where it is screwed into the male screw portion 19a, and an image may be actually formed in order to check whether or not an image is formed without any trouble. As a result, the actuator shaft 19 rotates to move the actuator 14 to the sliding portion 19b, so that the counter circuit cannot be reset if shipped as it is.

Therefore, in the assembly process, when the actuator 14 is disengaged from the male screw portion 19a and is in the position 14 'in FIG. 3,
Actuator shaft 19 by twisting protrusion 14e as shown by arrow 14 ″
The snap arms 14b, 14c may be bent by pulling them away from the actuator 14 to remove the actuator 14, and the snap arms 14b, 14c may be fitted to the male screw portion 19a again so as to bend.

As described above, according to the present invention, the actuator 14 can be detached and attached very easily by holding the actuator 14 on the actuator shaft 19 with the flexible snap arms 14b and 14c, but the protrusion 14e protrudes to the outside of the cleaner 13. Because
It is possible that it may come off from the actuator shaft 19 at unexpected times, and if you try to return it to the original position, it will fit into the male screw part 19a and reset the counting circuit, or other unexpected inconvenience may occur, so No 6
As shown in the figure, it is advisable to remove the protruding portion of the switch switching lever 16 except for the portion that inhibits the detection arm 16a when all the steps such as assembly and inspection are completed.

FIG. 6 shows an embodiment thus constructed.

In the figure, the actuator 28 has a flexible switch arm 28b, 28c, a rotation stopping arm 28d, a protrusion 28e that can suppress the detection arm 16a, a slipping 28f, a knob 28g, a step portion 28h,
Although not shown in FIG. 6, it has a female screw portion 28a that can be screwed into the male screw portion 19a.

Like the above-mentioned actuator 14, the actuator 28 is detached from the sliding portion 19b by holding the knob 28g after the assembly inspection and then fitted into the male screw portion 19a, and then the pliers and other tools are used to remove the screw 28f from the portion. The portion of the knob 28g is cut off from the protrusion 28e by, for example, breaking it. By doing so, there is no portion protruding outside the cleaner 13 and part of the step portion 28h is covered inside the casing of the cleaner 13 shown in FIG. It is possible to prevent from accidents such as slipping out of 19. In addition, for dustproof and other purposes, the cutout is made after the final inspection by using a cover that cuts the operating part of the detection arm 16a and made it an opening.
13c may be closed.

[Effect of device]

According to the present invention, as described above, it is easy to attach the actuator at the time of assembling the image forming unit, and the actuator is temporarily moved for the assembly inspection of the image forming unit to move from the male screw portion of the actuator shaft to the female screw of the actuator. After the parts are removed, screwing the male screw part and the female screw part in the final shipping state again, that is, in a predetermined position where the actuator can operate the switch, can be performed by reversing the male screw part or disassembling and screwing again. Since it can be performed with one touch, so to speak, without the need for reassembling, the restoration after the inspection can be made extremely simple and in a short time. Therefore, the inspection time including the above restoration is shortened, and the processing cost can be significantly reduced. Further, since the protruding portion protruding to the outside of the cleaner can be eliminated as necessary, troubles caused by the protruding portion can be prevented and safe operation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an essential part of an embodiment of the present invention, FIG. 2 is an operation diagram showing another state of FIG. 1, and FIG. 3 is an arrow III-III portion of FIG. Schematic cross-sectional views, FIGS. 4 (a) and 4 (b) are enlarged views of the actuator of FIG. 1, FIG. 4 (c) is a developed cross-sectional view of a portion C-C in FIG. 4 (b), 5 is a perspective view of FIG. 4 (b), FIG. 6 is a perspective view showing another embodiment of the present invention, and FIG. 7 is a schematic sectional view showing an image forming unit to which the embodiment of the present invention is applied. FIG. 8 is a schematic sectional view showing an image forming apparatus incorporating the image forming unit shown in FIG. 7, and FIG. 9 is a schematic sectional view showing a conventional example. 11 ... Photosensitive drum, 11a ... Drum gear, 12 ... Charger, 13
... Cleaner, 13a, 13b ... Stopper, 13c ... Notch, 14 ... Actuator, 14a ... Female screw part, 14b, 14c ... Snap arm,
14d ... rotation stopping arm, 14e ... projection, 15 ... image forming unit, 16 ... switch switching lever, 16a ... detection arm, 16b ...
Switch arm, 16c ... Shaft, 16d ... Switch spring, 17 ... Image forming device, 18 ... Micro switch, 18a ... Pin plunger, 19 ... Actuator shaft, 19a ... Male screw part, 19b ... Sliding part, 19c ... Actuator gear, 19d ... Transfer coil, 20 ... Developer, 20a ... Toner box, 20b ... Initial developer, 20c ...
Developer tank, 20d ... Doctor blade, 20e ... Developing sleeve, 20e ... Developing sleeve, 21 ... Paper, 22 ... Arrow, 23 ... Transfer device, 24 ... Printing means, 25 ... Fixing device, 26 ... Face-up tray, 27 ... Face down tray.

Claims (1)

(57) [Scope of utility model registration request] 1. An image forming unit that includes an image forming element and is detachably attached to an image forming apparatus main body, the unit being at a first position on a rotation shaft when not in use, and being attached to the apparatus main body. In an image forming unit detection device including a moving member that is used when an image forming operation is performed and moves from the first position to a second position in the rotation axis direction, the moving member is attachable to the rotation shaft. An image forming unit detection device having a flexible grip portion.