JP2002006692A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly grasp the number of revolution times of a rotary type developing device unit in order to recognize the time for exchange of members which are deteriorated by accompanying the revolutions of this unit by providing the device with a means for measuring the number of revolution times. SOLUTION: A projecting part 461 is disposed at one point at the end of a disk-shaped plate of a front side plate 460a of the revolver developing unit 4 and a light transmission type sensor 465 is disposed in proximity to the end of the front side plate. Every time the revolver developing unit 4 rotates, the shut-off signals emitted by shutting off of the optical path of the light transmission type sensor by the projecting part described above are counted and the number of revolution times of the revolver developing unit is obtained. The results of the measurement are displayed in a display section 467 for the number of revolution times of a printer body. A service engineer or the like is able to predict the deterioration state or consumption state of the parts from the number of revolution times displayed on the display section for the number of revolution times and is able to properly carry out maintenance.

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 such as a copying machine, a facsimile, and a printer.
The present invention relates to an image forming apparatus having a rotary developing device unit rotatably provided close to a photoconductor as a latent image carrier and having a plurality of developing devices around a rotation center.

[0002]

2. Description of the Related Art Conventionally, this type of image forming apparatus rotates a rotary developing unit to sequentially position each developing unit at a developing position facing a photoconductor, thereby forming a latent image on the photoconductor. Develop with each color toner. There are various members around the rotary developing unit that come into contact with each other and receive an external force due to the rotation of the rotary developing unit.

For example, as a first example, among the developing devices provided in the rotary developing unit, a developer carrying member and a developer supply member of the developing device which come to a developing position by rotation of the rotary developing unit are provided. For example, there are a developer carrier driving gear and a developer supply member driving gear for driving the components. These drive gears come into contact with and mesh with the input gears provided on the developer carrying member and the developer supply member of the developing device each time the developing device that comes to the developing position is switched. Receive.

Further, as a second example, there is a bias terminal for supplying a developing bias to a developer carrier. FIG.
(A) and (b) show a developing sleeve 4 as a developer carrying member.
FIG. 4 is an explanatory diagram showing an example of a mechanism of applying a developing bias to the image data 01. As shown in FIG. 9A, the bias terminal 42
Reference numeral 0 indicates that the end 420a projecting in a hemispherical shape is provided so as to face the shaft end of the developing sleeve, and is pressed against the shaft end of the developing sleeve by a spring 421 attached to the apparatus main body. The developing sleeve shaft 411 is connected to the rotary developing unit 4.
When the developer moves to the developing position just opposite to the photosensitive drum 1, the developing sleeve shaft end and the bias terminal 420 come into contact with each other as shown in FIG. That is, each time the developing device having the developing sleeve 401 comes near the developing position, the bias terminal 420 receives an external force due to contact with the shaft end of the developing sleeve 401.

[0005] As a third example, there is an output terminal provided for supplying power to members which require power for the power supply of a sensor in the rotary type developing unit 4 and the transmission and reception of signals, and the like. FIG. 10A is an explanatory diagram showing a mechanism of power supply to the rotary developing unit 4. In this figure, a contact terminal 4 serving as an output terminal for supplying electric power to the developing device is provided at one longitudinal end of the rotary developing unit 4.
The output terminal is fixed to the slip ring 430. FIG. 10B is a partially enlarged view showing a connection state between the rotation shaft of the rotary developing unit and the slip ring 430. As shown in this figure, a rotor 440 as an input terminal provided on the surface of the rotary shaft of the rotary developing unit 4 comes in contact with the four contact terminals 450 of the slip ring to supply a desired current to the developing device. Is done. When the rotary developing unit 4 rotates, the rotation axis of the unit 4 rotates, and the contact terminal 450 and the rotor 440 are rotated.
Move relative to each other in a contact state and receive an external force.

[0006]

However, as the rotation of the rotary developing unit is repeated, members on the rotary developing unit side and members around the rotary developing unit which receive an external force due to the rotation of the unit. It was found that each of the contact portions was worn, and the original function gradually decreased.

For example, in the first of the above three examples, in the first example, the input gear of the rotary type developing unit and the input gear only when the input gear comes to a predetermined position due to the rotation of the rotary type developing unit. With the output gear provided to mesh with the gears, at the moment when the gears mesh with each other, the gear teeth of the respective gears receive an impact and gradually wear. The shaft end of the developing sleeve and the bias terminal 420 in the second example are
As shown in FIG. 9B, each time the end of the developing sleeve shaft 411 comes into contact with the bias terminal 420, an impact is applied between the two. It will be worn. The contact between the rotor 440 provided on the rotating shaft of the rotary type developing unit 4 and the contact terminal 450 of the slip ring in the third example is continuously performed in the contact state, so that the contact between them is maintained. Parts wear unexpectedly.

[0008] Such abrasion of the contact portion may similarly occur if any member other than the above collides or moves relatively in the contact state. It is considered that the more the number is, the more the deterioration due to wear becomes. Then, it is necessary to perform maintenance such as replacement of a worn member to some extent.

Conventionally, the number of copies has been counted, and the maintenance time of the various components has been estimated from the number of copies.

Here, if the rotation of the rotary developing unit is performed only for forming an image on transfer paper, the number of rotations of the rotary developing unit can be estimated almost accurately from the number of copies. . However, in practice, there is a case where the rotary developing unit is rotated even though no image is formed on the transfer paper, and it is difficult to estimate the number of rotations of the unit only from the number of copies. For example, process control has recently been performed to suppress image quality fluctuation due to environmental fluctuations and temporal fluctuations. The process control, for example, forms an image of a certain toner pattern on the intermediate transfer body, detects the image density with an optical sensor, grasps the developing ability from the density change, and issues an instruction such as toner replenishment as necessary. Things,
No image is formed on the transfer paper, and almost all other device operations are performed. However, it is not counted in the number of copies.

The present invention has been made in view of the above background, and an object of the present invention is to provide an image forming apparatus capable of accurately grasping the number of rotations of a rotary developing unit.

[0012]

According to a first aspect of the present invention, there is provided an image forming apparatus having a latent image carrier having a latent image on a surface thereof and a plurality of developing units. A rotary developing unit that is rotatably supported on the
In an image forming apparatus that performs development by moving a desired developing device to a developing position facing the latent image carrier by rotation of the rotary developing device unit, a rotation for measuring the number of rotations of the rotary developing device unit is performed. It is characterized in that a number-of-times measuring means is provided.

In the image forming apparatus according to the first aspect, the actual number of rotations of the rotary developing unit is measured by the number-of-rotations measuring means.

According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, further comprising a number of rotations display means for displaying the number of rotations of the rotary type developing unit measured by the number of rotations measurement means. It is characterized by the following.

According to the image forming apparatus of the present invention, a serviceman or a user can easily know the number of rotations by checking the number of rotations of the rotary developing unit displayed by the number-of-rotation display means.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the first or second aspect, further comprising rotation number reset means for resetting the number of rotations of the rotary type developing unit measured by the rotation number measuring means. It is characterized by the following.

Here, the timing of resetting by the number-of-rotations resetting means may be when a member whose number of rotations of the unit is an index of the degree of deterioration is replaced. The number of rotations may be reset to 0 or 1 depending on the setting of the device.

In the image forming apparatus according to the third aspect, the number of rotations of the rotary developing unit is reset by the number of rotation resetting unit immediately after replacing a component that deteriorates with the rotation of the rotary developing unit. Thus, the next replacement time of the newly mounted component can be accurately grasped from the number of rotations of the unit.

According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the image forming apparatus of (2) or (3), when the number of rotations measured by the number of rotations measuring means reaches a predetermined number set in advance, a notifying means for notifying that the predetermined number has been provided is provided. It is a feature.

In the image forming apparatus according to the fourth aspect, when the number of rotations of the rotary type developing unit reaches a predetermined number set in advance, the notifying means notifies the fact. Therefore, if you set the number of rotations to replace parts that gradually deteriorate due to the rotation of the rotary developing unit, the notification means will accurately inform you of the replacement time even if the service person or user is not conscious. .

According to a fifth aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the image forming apparatus of 2, 3, or 4, when the rotary developing unit is located at a preset home position, home position detecting means for detecting that the rotary developing unit is located at the home position; The above-mentioned rotation number measuring means is constituted by a home position detection number measuring means for counting the number of times that the detection means detects the position at the home position.

In the image forming apparatus of the present invention, the home position detecting means detects that the rotary developing unit is located at the home position, and the home position detecting number measuring means measures the number of times of detection. The number of times of detection is defined as the number of rotations of the rotary developing unit. If the home position detecting unit is originally provided in the image forming apparatus, it is not necessary to provide a new detecting unit for measuring the number of rotations of the rotary type developing unit by using this.

According to a sixth aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the image forming apparatus according to any one of 2, 3 and 4, the rotary driving device for rotating the rotary developing unit rotates the rotary developing unit by a rotary driving signal sent to the rotary driving device. The rotation frequency measurement means
The number of rotations of the rotary developing unit is converted from the rotation drive signal.

According to the image forming apparatus of the present invention, a rotation drive signal originally sent to the rotation drive unit for driving the rotation of the rotation type development unit is used, and this is converted to convert the rotation drive signal of the rotation type development unit. Derive the number of rotations. The rotary driving device that receives the driving signal always rotates the rotary developing unit in response to the signal, and there is a close relationship between the driving signal and the number of rotations of the rotary developing unit. Therefore, it is possible to know the exact number of rotations of the rotary developing unit.

According to a seventh aspect of the present invention, in the image forming apparatus of the sixth aspect, a stepping motor is used as the rotation driving device, and the rotation driving signal is determined by the number of pulses sent to the stepping motor. It is characterized by having.

In the image forming apparatus of the present invention, the number of pulses sent to the stepping motor is counted, and the number of pulses counted with respect to the number of pulses corresponding to one rotation of the rotary type developing unit is determined. The number of rotations of the rotary developing unit is obtained depending on whether or not it corresponds. This makes it possible to know the exact number of rotations of the rotary developing unit.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments 1 to 3 in which the present invention is applied to a color image forming apparatus (hereinafter, referred to as a "printer") as an image forming apparatus will be described.

[First Embodiment] FIG. 1 is a schematic configuration diagram of a printer according to a first embodiment. In FIG. 1, around a photoreceptor drum 1 as a latent image carrier, a charging charger 2 as a charging unit, an optical writing unit 3 as a laser writing unit including a polygon mirror and an fθ lens, and a rotary developing unit A revolver developing unit 4, an intermediate transfer belt 5 as an intermediate transfer unit, a charge elimination charger 6 as a charge elimination unit, a drum cleaning unit 7 as a cleaning unit for the photosensitive drum 1, and the like. In FIG. 1, the photosensitive drum 1
Is rotated counterclockwise by driving means (not shown). The intermediate transfer belt 5 is stretched around a plurality of rollers, and is rotated clockwise in synchronization with the photosensitive drum 1.

The revolver developing unit 4 is provided with four first, second, third, and fourth developing devices that individually store toners of yellow, magenta, cyan, and black, respectively. I have. Around the intermediate transfer belt 5, a transfer belt 8 as a secondary transfer unit, a belt cleaning unit 9 as a cleaning unit for the intermediate transfer belt 5, and the like are provided.

A reading unit 200 as an image reading means is mounted on the upper part of the printer main body 100. The reading unit 200 includes a contact glass 201 serving as a document placing table on which a document image is placed, scanners 202 and 203 for scanning the document image placed on the contact glass 201, and captures images scanned by the scanners 202 and 203. And the like. Further, a paper feed unit 300 as a paper feed unit is provided below the printer main body 100. The paper feed unit 300 includes first, second, and third paper feed trays 301, 302, and 30 that store paper of different sizes.
3. Double-sided unit 304 that feeds the paper on which an image is formed on one side after being fed from each of paper feed trays 301, 302, and 303, and is collected by drum cleaning unit 7 and belt cleaning unit 9 A waste toner tank 305 for storing toner is provided.

In FIG. 1, when the printing operation is started, first, the photosensitive drum 1 rotates, and the surface of the photosensitive drum 1 is uniformly charged by the charging charger 2. Next, based on the image signal read by the reading unit 200 or the image signal imported from another device, the first color image light that has been color-separated on the surface of the photosensitive drum 1 by the optical writing unit 3 is generated. Exposed. Thereby, the surface of the photosensitive drum 1 is
An electrostatic latent image of the color image is formed.

The first color electrostatic latent image formed on the photosensitive drum 1 is formed into a toner image by the first color toner supplied from the first developing device mounted on the revolver developing unit 4. . Then, the first color toner image formed on the photosensitive drum 1 is intermediately transferred by a primary transfer roller 10 as a primary transfer unit in a primary transfer nip where the photosensitive drum 1 and the intermediate transfer belt 5 are in contact with each other. The primary transfer is performed on the transfer belt 5.

Next, the surface of the photosensitive drum 1 after the primary transfer of the first color toner image onto the intermediate transfer belt 5 is cleaned by the drum cleaning unit 7. Then, when the residual toner of the first color remaining on the surface of the photosensitive drum 1 is cleaned, the surface of the photosensitive drum 1 is uniformly charged again by the charging charger 2. Thereafter, the surface of the photosensitive drum 1 is exposed to the second color image light by the optical writing unit 3 to form an electrostatic latent image of the second color image on the surface of the photosensitive drum 1.

The second color electrostatic latent image formed on the photosensitive drum 1 is formed into a toner image by the second color toner supplied from the second developing device of the revolver developing unit 4. Then, 2 formed on the photosensitive drum 1
The color toner image is formed by the primary transfer roller 10.
In the primary transfer nip portion, the primary transfer is superimposed on the first color toner image primarily transferred onto the intermediate transfer belt 5.

After the primary transfer of the toner image of the second color is completed, the surface of the photosensitive drum 1 is uniformly charged again by the charging charger 2 after the residual toner of the second color is cleaned by the drum cleaning unit 7. Is done. Then, the surface of the photosensitive drum 1 is exposed to the third color image light by the optical writing unit 3 to form an electrostatic latent image of the third color image.

The third-color electrostatic latent image formed on the photosensitive drum 1 is formed into a toner image by the third-color toner supplied from the third developing unit of the revolver developing unit 4. Then, 3 formed on the photosensitive drum 1
The color toner image is formed by the primary transfer roller 10.
In the primary transfer nip portion, the primary transfer is superimposed on the first color and second color toner images primarily transferred on the intermediate transfer belt 5.

After the primary transfer of the toner image of the third color is completed, the surface of the photosensitive drum 1 on which the residual toner of the third color has been cleaned by the drum cleaning unit 7 is uniformly charged again by the charging charger 2. Is done. The surface of the photosensitive drum 1 is exposed to the image light of the fourth color by the optical writing unit 3 to form an electrostatic latent image of the image of the fourth color.

The fourth-color electrostatic latent image formed on the photosensitive drum 1 is formed into a toner image by a fourth-color toner supplied from a fourth developing device mounted on the revolver developing unit 4. . Then, the fourth color toner image formed on the photosensitive drum 1 is transferred to the primary transfer roller 10.
As a result, the primary transfer is superimposed on the first color, second color, and third color toner images primarily transferred onto the intermediate transfer belt 5 in the primary transfer nip. As a result, yellow, magenta,
A full-color toner image including cyan and black toner images is formed.

On the other hand, while the toner images of the respective colors are primary-transferred onto the intermediate transfer belt 5 as described above, a paper feed tray designated in advance in the paper feed unit 300 or the side of the printer main body 100. One sheet of transfer paper as a transfer material is supplied from a manual paper supply tray 11 provided in the unit by a paper supply roller. This transfer paper is on standby while being held between registration rollers 12 that convey the transfer paper toward a secondary transfer nip between the intermediate transfer belt 5 and the transfer belt 8.

The registration roller 12 feeds the transfer paper at a timing when the front end of the image transfer area of the transfer paper coincides with the front end of the full-color toner image formed on the intermediate transfer belt 5. As a result, in the secondary transfer nip, the full-color toner image formed on the intermediate transfer belt 5 is secondarily transferred (collectively transferred) to the image transfer area of the transfer paper. The transfer paper on which the full-color toner image is collectively transferred in this way is conveyed toward the fixing device 14 by the conveying belt 13 and the full-color toner image is fixed by the fixing device 14.
It is discharged outside.

The surface of the photosensitive drum 1 after the primary transfer of the fourth color toner image onto the intermediate transfer belt 5 is cleaned by the drum cleaning unit 7 to form the next original image. Prepare. The residual toner of each color removed from the surface of the photosensitive drum 1 by the drum cleaning unit 7 is transferred to the waste toner tank 30 by a toner transport unit (not shown).
5 to be stored. Similarly, the residual toner remaining on the intermediate transfer belt 5 without being transferred onto the transfer paper is also removed from the intermediate transfer belt 5 by the belt cleaning unit 9, and then the waste toner tank 30 is removed.
5 to be stored. Then, the residual toner stored in the waste toner tank 305 is discarded when it becomes full.

FIGS. 2 and 3A to 3C show the internal structure of the revolver developing unit 4. FIG. The revolver developing unit 4 includes a developing device 400Y containing yellow toner and a developing device 40Y containing cyan toner.
0C, developing device 400 containing magenta toner
A revolver development system in which a developing device 400K containing M and black toners is integrated is employed. Also,
The revolver developing unit 4 is provided with the printer main body 10.
Drawer unit 50 configured to be freely drawable with respect to zero
0. As a result, each developing device of the revolver developing unit 4 can be easily removed, and maintenance of each developing device is improved.

As shown in FIGS. 2 and 3A, when the revolver developing unit 4 rotates counterclockwise,
Each developing unit faces a developing site facing the photosensitive drum 1 in the order of 400K, 400C, 400M, and 400Y. As a result, the electrostatic latent images of the respective colors formed on the photosensitive drum 1 are successively developed (toner images) by the toners of the respective colors supplied by the developing sleeves 401 of the respective developing devices.

As shown in FIG. 3B, the revolver developing unit 4 in the drawer unit 500 is supported around ring members 402 and 403 on the front and rear side plates (not shown) of the revolver. Driven independently by a revolver drive motor.

Each of the developing devices 400K, 400C and 400 held around the rotation axis of the revolver developing unit 4
M and 400Y are at the time of non-image forming operation, that is, before and after the image forming operation, as shown in FIG.
The developing sleeves of 00K, 400C, 400M, and 400Y are stopped at positions separated from the surface of the photoconductor (hereinafter, referred to as home positions). Specifically, the black developing device 40 is rotated in the rotation direction of the revolver developing unit 4.
The rotation stops at a position 30 ° before the rotation angle 0K comes to the development position. After the end of the image forming operation, a homing operation for stopping at the home position is always performed. This is effective to prevent background contamination on the photosensitive drum 1 and toner consumption at times other than development, by keeping a space between the developing sleeve 401 and the photosensitive drum 1 when the apparatus is moved. is there. Power ON
The homing operation is always performed at the time of toner replacement.

Hereinafter, the above four developing units 400K, 400
Since C, 400M, and 400Y have exactly the same configuration, only the internal structure of the black developing device 400K will be described.
The description of the internal structure of the other developing units 400Y, 400M, and 400C is omitted.

The developing device 400K includes a developing sleeve 401K.
And a stirring screw 405K for stirring a two-component developer (hereinafter, referred to as a developer) including a black toner and a carrier housed in the casing, and a toner housed in a toner cartridge as a toner container in the casing. And a toner supply screw 407K for replenishment (see FIG. 2).

The toner in the developer contained in the casing of the developing device 400K is gradually consumed by visualizing the electrostatic latent image on the photosensitive drum 1. Then, when the toner concentration of the developer falls to a concentration equal to or lower than a predetermined concentration, toner is supplied from the toner cartridge into the developing device 400K by rotation of the toner supply screw 407K. Thereby, the toner density of the developer can be maintained at a predetermined density or higher.

Next, a description will be given of driving means for rotating and driving the developing sleeve 401K and the stirring screw 405K of the developing device at the developing position. The driving means of the developing sleeve 401K includes a developing sleeve driving motor as a driving source (not shown) and a drive transmitting mechanism for transmitting a driving force from the developing sleeve driving motor to the developing sleeve 401K. As shown in FIG. 2, this drive transmission mechanism is engaged with a developing drive input gear 406 provided for each developing device of the revolver developing unit 4 and a developing drive input gear 406K of the developing device located at the developing position. Developing drive gear 4 for transmitting a driving force to the developing sleeve 401K of the developing device.
07. Then, the driving force is transmitted from the developing drive gear 407 to the developing drive input gear 406K in such a direction as to oppose the rotation of the revolver developing unit 4. On the other hand, the drive means of the stirring screw 405K includes a stirring screw drive motor as a drive source (not shown) and a drive transmission mechanism for transmitting a driving force from the stirring screw drive motor to the stirring screw 405K. . This drive transmission mechanism, as shown in FIG.
The driving force is transmitted to the developing sleeve of the developing device by engaging with the screw driving input gear 408K provided for each developing device of the revolver developing unit 4 and the screw driving input gear 408K of the developing device located at the developing position. And a screw drive gear 409. Then, the driving force is transmitted from the screw driving gear 409 to the screw driving input gear 408K, and further transmitted from the screw driving input gear 408K to a gear provided on the stirring screw 405K. The development drive gear 407 and the screw drive gear 409 are connected to the development drive input gear 406 and the screw drive input gear 408 of the four developing units of the revolver development unit 4 when they arrive at the development position, and are separated from the development position. You will be removed as you do.

A developing bias is applied to the developing sleeve 401 of the developing device at the developing position, so that a developing electric field can be formed. FIG. 4 is an explanatory diagram of the developing bias applying mechanism. As shown in this figure, a developing bias power supply 422 is connected to a fixed position of the rear side plate of the color printer main body facing the end of the developing sleeve shaft 411 as a developing bias input section of the developing device located at the developing position. Further, a developing bias terminal 420 made of a conductive rod-shaped terminal for applying a developing bias is provided. The bias terminal 420 is urged to be pushed toward the shaft end of the developing sleeve by a conductive spring 421, and the tip is formed in a hemispherical shape. Thus, the contact pressure between the bias terminal and the developing sleeve shaft 411 can be kept constant by the spring pressure. With the above configuration, the shaft end of the developing sleeve 401 arriving at the portion facing the developing bias terminal with the rotation of the revolver developing unit 4 reliably comes into contact with the tip of the developing bias terminal and the developing device at the developing position Only the developing bias is applied.

The developing bias power supply 422 is configured to apply a developing bias in which an AC voltage is superimposed on a DC voltage to the developing bias terminal 420. The output of the AC voltage from the developing bias power supply 422 is ON / OF independently of the DC voltage at a predetermined timing based on a control signal from a control unit (not shown).
F can be switched. This allows
At the start and end of the rotation of the revolver developing unit 4, the application of the alternating current (AC) component of the developing bias is turned off, and only the direct current (AC) component is applied to prevent the toner from adhering to the photosensitive drum 1.

By the way, in the printer having the above configuration, as the rotation of the revolver developing unit 4 is repeatedly performed, members on the revolver developing unit 4 side and members around the unit 4 that relatively moves in contact with the members are changed. The contact and separation of various members are repeatedly performed during the operation. For this reason, it has been found that the contact portion of each member is worn or deteriorated due to the external force with the passage of time, so that the original function cannot be sufficiently exhibited.

For example, the developing drive input gear 406 and the screw drive input gear 408 that engage with the developing drive gear 407 and the screw drive gear 409 only when they come to the developing position, the gear teeth of each other apply external force at the moment when the gears mesh. It gradually wears out. The developing sleeve 40
Since the bias terminal 420 is provided so as to contact the shaft end of the developing sleeve 401 of the developing device that has come to the developing position in order to apply the developing bias to 1, the contact portion receives an external force each time the two contact. It is unexpectedly worn (see FIG. 9B). Further, since a contact terminal 450 is provided for supplying power to the developing device, the contact terminal 450 being relatively moved in contact with the rotor 440 provided on the rotating shaft of the revolver developing unit. Therefore, both contact portions are unexpectedly worn due to the external force (see FIGS. 10A and 10B). Then, it is necessary to perform maintenance such as replacement of a member that has been degraded due to some external force.

In the printer of the first embodiment, the number of rotations of the revolver developing unit 4, which is an index of the replacement time of the deteriorated member, can be accurately grasped.

The features of the first embodiment will be described below. FIG. 5 is an explanatory diagram of the periphery of the revolver developing unit 4 provided with a rotation number measuring device as a rotation number measuring unit which is a characteristic part of the first embodiment. This figure shows the rotating shaft of the revolver developing unit 4 and the front and rear side plates 460a and 460b. In the first embodiment, the front side plate 460
A projection 461 is provided at one end of the disk-shaped plate a, and the light-transmitting sensor 465 is provided near the end of the front plate.
Is provided. The light transmission type sensor 465 has a U-shaped concave portion, and is positioned and fixed to the main body of the apparatus in such a manner that the projecting portion passes through the concave portion when the revolver developing unit 4 rotates. In this configuration, when the revolver developing unit 4 rotates, the protruding portion interrupts the optical path of the light transmission type sensor 465 for each rotation of the unit, emits a shutoff signal once per rotation, and counts this signal to count the revolver. The number of rotations of the developing unit 4 is measured. Also,
A rotation number display section 467 as rotation number display means for displaying the count result is provided on a display section of the printer body.

The operation of the printer 1 having the above configuration will be described. FIG. 6A is a control block diagram illustrating a part of the control of the printer 1 according to the first embodiment. FIG.
As shown in (a), the printer 1 according to the present embodiment includes a rotation number display unit 467 as notification means for displaying the number of rotations of the revolver developing unit 4 obtained from the detection result of the light transmission type sensor 465; A main body control unit 466 for controlling the display content on the number display unit 467 based on the detection result of the light transmission type sensor 465. Number of rotations display 4
Reference numeral 67 has a scale 467a indicating the number of rotations and a display lamp provided at each scale position, and the display lamp is turned on at the corresponding scale position indicating the number of rotations. With the above-described configuration, when the light transmission sensor 465 receives the cutoff signal once, the main body control unit counts it once, and displays the integrated number of rotations added to the immediately preceding number of times as the number of rotations display unit 46.
7 is displayed. Thereby, a service person or the like can know the cumulative number of rotations from the start of counting of the revolver rotation unit 4.

FIG. 6B is an explanatory view showing the number-of-rotations display section. The number-of-revolutions display section is provided with a reset button 468 as a number-of-revolutions resetting means for resetting a displayed numerical value. In the present embodiment, when the reset button 468 is pressed, the display of the number of rotations returns to 0, and the revolver developing unit 4 that has newly rotated since then is displayed.
Is displayed on this display unit.

According to the above configuration, since the actual number of rotations of the revolver developing unit 4 is measured and displayed, a service person or the like can easily grasp the accurate number of rotations of the revolver developing unit 4. Therefore, a more accurate number of rotations can be obtained than estimating the number of rotations of the revolver developing unit 4 by back calculation from the number of copies. The number of rotations displayed on the number-of-times-of-rotation display portion can predict the deterioration state or the wear state of the component, and can replace or replenish the component before the component is damaged or completely consumed, thereby eliminating the equipment downtime. . Also, a reset button 468
If the number of rotations can be reset, the number of rotations can be reset to 0, such as after replacing a component that deteriorates with the rotation of the revolver developing unit 4, and the number of rotations can be reset. The next replacement time can be easily grasped from the number of rotations.

Normally, the number of rotations display section 467 need only be checked by a serviceman during maintenance, and there is little need for the user to grasp the display contents. For this reason, it is desirable that the display is provided in a place where the user cannot see or that the display mode can be switched to the display mode for the serviceman so that the display is performed only in that mode. By doing so, it is possible to prevent the user from pressing the reset button by mistake.

Here, once the number of rotations is reset by the reset button 468, the number of rotations display section 467 of the printer 1 according to the first embodiment can know only the number of rotations after the reset. Instead of this display unit, the number of rotations can be displayed in two ways. One is the same display as above, and the other is that the number of rotations is not reset even if the reset button is pressed, and the number of unit rotations from the beginning is displayed. The integrated value may be displayed continuously. By doing so, even if the number of rotations is reset each time parts are replaced or replenished, the number of rotations of the revolver developing unit 4 from the beginning can be grasped at any time.

In this embodiment, the number of rotations is returned to 0 by the reset button 468, but may be set to return to 1.

As a method of measuring the number of rotations of the revolver developing unit 4, the above-mentioned projection and the light transmission type sensor 4 are used.
The method is not limited to the method described above. As a method other than the above, for example, a configuration in which a reflective seal that reflects light is provided at one location on the outer peripheral surface of the revolver developing unit 4, a reflective sensor is provided in the apparatus main body, and the number of rotations is measured by the number of times the reflected light is detected, Can be considered.

Further, there is a method in which a home position sensor 469 as home position detecting means for detecting whether or not the revolver developing unit 4 is at the home position is used for measuring the number of rotations of the revolver developing unit 4. FIG. 7 is a partially enlarged view of the revolver developing unit 4 provided with the home position sensor 469. As shown in this figure, a home position sensor 469 is provided on the apparatus main body so as to face the front plate 460a of the revolver developing unit 4, and a projection 470 is provided on the front plate 460a. With this, it is possible to detect that the protrusion 470 passes through the sensor 469 by the rotation of the revolver developing unit 4 by a mechanism similar to the above-described rotation number measuring device, and a predetermined time after the detection of the protrusion 470 by the sensor. The home position can be maintained by stopping the rotation after rotating the unit 4 by the rotation angle of. The home position detection number measuring means for measuring the number of times of detection by the home position sensor 469 can be used as the rotation number measuring means of the rotary developing unit.

If the number of rotations of the rotary developing unit is obtained by measuring the number of detections by the home position sensor 469, it is not necessary to newly provide a device for measuring the number of rotations. And cost reduction.

[Second Embodiment] Next, a second embodiment will be described. Note that, in the following, a description of portions common to the first embodiment in the printer 1 of the second embodiment will be omitted, and only the features of the second embodiment will be described. First, the basic device configuration of the printer 1 of the second embodiment is the same as that of the first embodiment except that the specification of the number-of-rotations display unit of the revolver developing unit 4 is different from that of the first embodiment.

FIG. 8A is a control block diagram showing a part of the control of the printer 1 according to the second embodiment. In the second embodiment, as in the first embodiment, the light transmission type sensor 465 is provided as a rotation number measuring device for measuring the number of rotations of the revolver developing unit 4. A display unit 472 is provided as notification means having different display contents.

The operation of the printer according to the second embodiment will be described. First, for each component that degrades or wears out due to rotation of the revolver developing unit 4 (hereinafter referred to as a rotation speed dependent consumable component), a predetermined number of rotations of the revolver developing unit 4 corresponding to a replacement time or an inspection time. The number of times (hereinafter referred to as an input value d) is input to the apparatus main body control unit 471 in advance. The main body control section 471 counts a shut-off signal emitted from the light transmission type sensor 465 for each rotation of the revolver developing unit 4 and compares the integrated rotation number added to the immediately preceding number with an input value previously input. I do. When the total number of rotations reaches the number of times of the input value, the display unit 472 displays that the component needs to be replaced or inspected. FIG. 8B is an explanatory diagram illustrating the display unit 472 according to the second embodiment. This display unit 472
When the number of rotations of the revolver developing unit 4 reaches the number of rotations of the input value d for each number of rotation-dependent consumable parts, this indicates that the corresponding part needs to be replaced or inspected. The display unit 472 is provided with a reset button 468 for each component to be displayed. When the serviceman presses the reset button 468 after replacing or inspecting the component, the number of rotations of the component is reduced to zero. It has been reset, and a new count can be started for the next replacement time.

According to the configuration of the second embodiment, since the display unit accurately displays the replacement time of the parts without the care of the serviceman or the user, maintenance such as the replacement time of the rotation speed dependent consumable parts is performed. The timing can be ascertained reliably.

[Third Embodiment] Next, a printer 1 according to a third embodiment will be described. This printer 1 differs from the first and second embodiments in the method of measuring the number of rotations of the revolver developing unit 4. In the first and second embodiments, the number of rotations is detected by a sensor. In the present embodiment, the number of rotations is detected by using a rotation drive signal sent to a revolver drive motor that drives the revolver developing unit 4. .

First, the revolver drive motor will be described. The revolver drive motor uses a two-phase excitation type stepping motor, and is configured to rotate the revolver developing unit 4 counterclockwise as viewed from the front of the unit. In the present embodiment, the revolver developing unit 4 can be rotated once by a signal of 200 pulses by using the stepping motor 404 of 1.8 ° per pulse. When driving the rotation of the revolver developing unit 4, a pulse is output from a main body control unit (not shown) to a driver (not shown), and this pulse is input to the motor, and one step of rotation is performed for one pulse. Is performed. The number of pulses corresponding to rotating by a predetermined rotation angle is output by the main body control unit, and the unit is rotated by 90 °.
The developing device can be sequentially rotated to the developing position by rotating the developing device.

In the third embodiment, the number of pulses sent to the stepping motor 404 for driving the rotation of the revolver developing unit 4 is counted, and the number of rotations of the revolver developing unit 4 is converted from the number of pulses. It is configured as follows. Specifically, a value obtained by dividing the number of pulses counted each time a pulse is output to the driver by the main body control unit by 200 is used as the number of rotations of the revolver developing unit 4.

According to the third embodiment, the number of rotations is measured by the motor 404 for driving the rotation of the revolver developing unit 4, so that it is not necessary to use a sensor. Can be avoided,
The number of rotations can be grasped more accurately.

The number of rotation-dependent consumable parts that are deteriorated or consumed by the rotation of the revolver developing unit is not limited to the parts described in the first to third embodiments. In addition to the above parts, contamination status of various sensors,
There are various parts whose state changes in proportion to the number of rotations of the revolver developing unit, such as the degree of wear of the developer and the degree of deterioration of the photosensitive drum, and the configuration of the present embodiment is also used for maintenance of such parts. Available.

[0074]

According to the image forming apparatus of the first aspect, since the actual number of rotations of the rotary developing unit is measured, the number of rotations of the rotary developing unit can be accurately grasped. effective. Also, based on this number of rotations, if parts that deteriorate due to the number of rotations of the unit are replaced and the deterioration state is checked, the replacement and deterioration state check time will be appropriate, and downtime due to damage to the parts will be reduced. There is an excellent effect that it can be eliminated.

According to the image forming apparatus of the second aspect, since the service person or the user can easily know the number of rotations, an excellent effect that the maintenance time such as the replacement time of the deteriorated part can be surely grasped. There is.

According to the image forming apparatus of the third aspect, the next replacement time of the newly mounted component can be accurately grasped.
There is an excellent effect that the maintenance time of parts, such as the time of replacement of deteriorated parts, can be ascertained reliably.

According to the image forming apparatus of the present invention, since the notifying means accurately informs the replacement time of the part without the service person or the user being conscious, the maintenance time such as the replacement time of the deteriorated part is grasped. Has an excellent effect that the device can be reliably managed and the device can be reliably managed.

According to the image forming apparatus of the fifth aspect, the number of times of detection by the home position detecting means is measured,
There is an excellent effect that the number of rotations of the rotary developing unit can be measured. In addition, in the case of an image forming apparatus in which a home position detecting unit is originally provided, there is no need to newly provide a detecting device for measuring the number of rotations, which is advantageous in that it contributes to space saving of the device and cost reduction. There is also an effect.

According to the image forming apparatus of the present invention, it is possible to know the exact number of rotations of the rotary type developing unit using the drive signal, so that a device for measuring the number of rotations is newly provided. This eliminates the necessity, and has an excellent effect of helping to save the space of the device and reduce the cost. Further, when the number of rotations is detected by the sensor, there is a risk of erroneous detection. However, according to the present invention, there is no such a possibility, and there is also an excellent effect that the number of rotations can be grasped more accurately.

According to the image forming apparatus of the present invention, it is possible to know the exact number of rotations of the rotary developing unit from the number of pulses, so that it is not necessary to newly provide a device for measuring the number of rotations. In addition, there is an excellent effect that the space of the device is saved and the cost is reduced. Also, since the number of rotations of the unit is converted from the number of pulses sent to the stepping motor, there is no need to be affected by erroneous detection or breakage of the sensor, and the superior effect that the number of rotations can be grasped more accurately is also obtained. is there.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printer according to a first embodiment.

FIG. 2 is an internal configuration diagram of the revolver developing unit according to the first embodiment.

FIGS. 3A to 3C are explanatory diagrams of a drive mechanism of the revolver developing unit. FIGS.

FIG. 4 is an explanatory diagram of a developing bias applying mechanism according to the first embodiment.

FIG. 5 is an explanatory diagram around a revolver developing unit, which is a characteristic part of the first embodiment.

FIG. 6A is a control block diagram illustrating a part of control of the printer according to the first embodiment. (B) is an explanatory view showing a rotation number display section.

FIG. 7 is a partially enlarged view of a revolver developing unit provided with a home position sensor.

FIG. 8A is a control block diagram illustrating a part of control of a printer according to a second embodiment. (B) is an explanatory view showing a display unit of the second embodiment.

FIGS. 9A and 9B are explanatory diagrams showing an example of a mechanism of applying a developing bias to a developing sleeve.

FIG. 10A is an explanatory diagram showing a mechanism of power supply to a rotary developing unit. FIG. 3B is a partially enlarged view showing a connection state between a rotary shaft of the rotary developing unit and the slip ring.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 charging charger 3 light writing unit 4 revolver developing unit 5 intermediate transfer belt 6 static elimination charger 7 drum cleaning unit 8 transfer belt 9 belt cleaning unit 10 primary transfer roller 11 manual feed tray 12 registration roller 13 transport belt 14 fixing Apparatus 100 Printer body 200 Reading unit 300 Feeding unit 400K, 400C, 400M, 400Y Developing device 401 Developing sleeve 401 404 Revolver drive motor 465 Light transmission type sensor 467 Number of rotations display 469 Home position sensor 472 Display 500 Display drawer unit

Claims (7)

[Claims] An image forming apparatus includes: a latent image carrier for carrying a latent image on a surface; and a rotary developing unit having a plurality of developing units and rotatably supported by an image forming apparatus main body. An image forming apparatus that performs development by moving a desired developing device to a developing position facing the latent image carrier by rotation of the developing unit, wherein a number of rotations measuring unit for measuring the number of rotations of the rotary developing unit is provided. An image forming apparatus, comprising: 2. An image forming apparatus according to claim 1, further comprising a rotation number display means for displaying the number of rotations of said rotary developing unit measured by said rotation number measurement means. 3. The image forming apparatus according to claim 1, further comprising a rotation number reset unit for resetting the number of rotations of said rotary type developing unit measured by said rotation number measuring unit. apparatus. 4. The image forming apparatus according to claim 1, wherein when the number of rotations measured by the number-of-rotations measuring means reaches a predetermined number set in advance, the predetermined number is reached. An image forming apparatus provided with a notifying means for notifying the user. 5. The image forming apparatus according to claim 1, wherein when the rotary developing unit is located at a predetermined home position, it is detected that the rotary developing unit is located at the home position. Home position detection means,
An image forming apparatus, wherein the home position detection means measures the number of times the home position is detected, and the home position detection number measurement means comprises the rotation number measurement means. 6. The image forming apparatus according to claim 1, wherein the rotary driving device for rotating the rotary developing unit is rotated by a rotary driving signal sent to the rotary driving device. An image forming apparatus for rotating a unit, wherein the rotation number measuring means is configured to convert the number of rotations of the rotary developing unit from the rotation drive signal. 7. An image forming apparatus according to claim 6, wherein a stepping motor is used as said rotation driving device, wherein said rotation driving signal is the number of pulses sent to said stepping motor. Forming equipment.