JPS63193156A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify a maintenance operation by storing the resistance value of a resistance element for discriminating a replaceable unit constituted of an image carrying body and a developing device, and an image forming sheet number, and displaying automatically the attainment of a service life sheet number. CONSTITUTION:A unit 126 is constituted so as to be replaceable by a photosensitive drum and a developing device, and in the end part of a coating cover 127, a resistance element 128 whose value is different extending from about several OMEGAs to several MOMEGAs at every unit is attached, connected to a body side by the connector terminal 128a of the resistance element 128, a resistance value measuring instrument for reading its resistance value as a voltage is provided, and the result of measurement is stored in a control part. Subsequently, a printing sheet number of each unit is stored in the control part and the remaining service life sheet number is decided, and when it reaches the service life sheet number scheduled in advance, it is displayed on a control panel, and the timing of replacement of the unit 126 is recognized automatically and surely.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is applicable to image forming apparatuses such as copying machines and printers.
The present invention relates to an improvement in an image forming apparatus having a unit that is detachably attached to a main body and that is converted according to the lifespan of the image forming apparatus.

(Prior art) In image forming devices such as electrophotographic devices, photoreceptor drums,
In addition, consumables that deteriorate due to fatigue or wear, such as developing devices, cleaning devices, and even fixing devices provided around the device must be replaced as needed. For this reason,
Conventionally, a total counter was installed in the main unit to count and display the number of images formed, and when the number of images displayed on the total counter reached a predetermined number, a service person or the like would replace each device that required replacement. We are currently checking and replacing the relevant equipment.

However, with such devices, service personnel have to manually check the number of images formed by visual inspection, and since the number of images formed is only the total number displayed on the total counter, maintenance is required. Specifically, it is implemented as follows. In other words, each time an operator or service person performs maintenance, he/she checks the total number of replacements for each device recorded in the service notes, etc. at the time of the previous replacement, compares it with the current total number, and replaces any new devices that have reached the specified number. The device will have to be replaced.

Moreover, the operator must check the total number on the total counter at any time and decide when to perform maintenance. As a result, maintainability is poor, and since all devices are checked manually as to when to replace them, errors may occur in reading or writing the total number, resulting in missed replacement times and replacements even though they are usable. There are various problems such as being stored away or being used even though the number exceeds the specified number, resulting in a decrease in image quality.

(Problem to be Solved by the Invention) Conventionally, when replacing consumables such as photoconductor drums and developing devices, service personnel refer to service notes and other information during maintenance and replace consumables such as photoconductor drums and developing devices when each device reaches the end of its service life. The operator must check whether the total number of sheets on the total counter has reached the predetermined number or not at any time regarding the maintenance period.
The maintenance is complicated, and since it is done manually, it is prone to errors.

Therefore, the present invention eliminates the above-mentioned problems, and allows the service person or operator to easily and reliably recognize that each device has reached the end of its service life, without requiring the service person to write in a service note or the like. The purpose is to provide an image forming apparatus that can perform the following functions.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention includes a display means for identifying each device, and also stores this display means and A control section is provided that totals the number of images formed for each device and controls the main body according to the results of this total.

(Function) According to the above-mentioned means, the present invention automatically displays a message to the operator or service person from the 5 main units when each device reaches its lifetime number, thereby simplifying the maintenance operation and further improving maintenance. The aim is to improve the reliability of the system.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 13. First, FIGS. 1 and 2 are front and rear external perspective views of a laser printer main body (10), which is an image forming apparatus of the present invention, and the main body (10) includes an upper cover (11) and a lower right cover. (12), lower cloth cover (13)
covered with. A water supply cover (14) is provided on the upper part of the upper cover (11), and is used on the negative side (14) for removing jammed sheet paper or during maintenance.
4a), while the right side of the upper cover (11) can be opened and closed around the - side (16a) for replacing the unit (3I), which will be described later. A right center cover (16) is provided, and a right center cover (16) is provided on the rear surface of the upper cover (11) for removing paper jams, etc.
A rear vehicle cover (17) is provided that can be opened and closed about a).

In addition, an interface connector (18) is provided on the side surface of the lower right cover (12) for transmitting and receiving signals from an external computer, word processor, etc. (not shown), which is a host system of one main unit (IO), and is connected to the lower right cover (13). A power cord (20'), a power switch (21), and a ground terminal (22) are provided on the rear surface.

Furthermore, a paper feed section (24) into which a removable paper feed cassette (23) is inserted is provided at the lower front of the main body (10), and a paper output tray (26) is removably attached above the paper feed section (24). There is. Furthermore, a control panel (27) consisting of an indicator lamp and a switch is provided on the front surface of the upper cover (11).

Next, FIG. 3 shows the inside of the main body (10), which is an image carrier with a diameter of approximately 3.
A charging device (33) consisting of a scorotron charger, a laser optical system (34), and a photoreceptor drum (32) are incorporated into a unit (31) around the photoreceptor drum (32) with a diameter of 0 (mm). A current a device (36) that performs cleaning at the same time, an irradiation lamp device (76), a transfer device (37) consisting of a corotron charger, and a static elimination lamp (38) are arranged in this order. Furthermore, a paper feed roller (40) with a partially cut-out cross-section is provided at the tip of the paper feed cassette (23) at the bottom of the main body (10) so as to be able to come into contact with the sheet paper (41) that is the transfer material. and paper cassette (2
3) The topmost sheet of paper taken out from
The paper is fed through sheet paper guides (42a) and (42b) to aligning rollers (43a) and (43b). Also, aligning roller (43a
), (43b) has a first magnet (
A first paper detection device (44a) consisting of a first lever (44b) having a first lever (44b) and a first reed switch (44c).
4) is provided. Furthermore, above the main body (10), there are a second sheet paper guide (46) that forms a conveyance path for the sheet paper (41) that reaches the paper output tray (26) from the aligning rollers (43a) and (43b), and an intermediate roller. (47a
), (47b), a third sheet paper guide (48), a fixing device (52) consisting of a heat roller (50) that has a built-in heater (50a) and whose temperature is detected by a thermistor (SOB) and a press roller (51). , paper ejection roller (53
a) and (53b) are provided. Further, in front of the paper ejection rollers (53a) and (53b), there is a second lever (54b) having a second magnet (54a) at the other end.
A second paper detection device (54) consisting of a second reed switch (54c) and a second reed switch (54c) is provided. Note that (55) is a control unit that controls each image forming apparatus, control panel (27), and the like.

Among the above devices, the laser optical system (34) uses a laser beam (
A polygon mirror (60a) rotated at high speed by a mirror motor (61) is used to scan the laser diode (60) that oscillates a laser diode (60a), which is focused by a collimator lens or a compressor lens (not shown). 62), and the laser beam (60a) reflected by the polygon mirror (62) is further transferred to the photoreceptor drum (3).
2) consists of a lens system (63) that irradiates the area.

Next, the unit (31) that integrally includes the photoreceptor drum (32) and the developing device (36) will be described in detail. The frame (70) includes a rail (10a) inside the main body (10).
The photosensitive drum (32) and the developing device (3G
), while the covering cover (71) on its upper surface, which also serves as the lid of the developing device (36), is used to convey the sheet paper (41) to the transfer position together with the second sheet paper guide (46). The covering cover (71) is shaped like a guide so as to constitute a part of the conveyance path of the paper sheet (41), and the cover (71) has a guide shape so that the conveyance direction of the sheet paper (41) is inclined inward from the tangential direction of the photoreceptor drum (32). It is also sloped. In addition, the covering cover (71
) A rib (71a) is formed on the upper surface to reduce friction with the sheet paper (41), and a drive section (not shown) is formed on the upper surface.
The lower intermediate roller (47b) is urged upward by a leaf spring (not shown) so as to follow the upper intermediate roller (47a) connected to the upper intermediate roller (47a). The lower intermediate roller (47b) is largely chamfered on both sides so as not to prevent the unit (31) from being attached or detached. Further, (72) is a handle used when opening the unit (31) J, which is rotatably attached to the attachment part (72a) and taken out from the recess (73) formed in the covering cover (71) when in use. On the other hand, when attached to the main body (10), the rib (71a
) is housed in the recess (73) so as not to protrude further, and furthermore, the upper part when housed is formed into a cylindrical shape to reduce resistance with the paper (41).

Note that (74) is a photoreceptor drum protection cover (11) which will be described later.
This is a slit that supports the negative side of 7). Further, an irradiation lamp device (76) is provided at the tip of the covering cover (71), and irradiates the entire surface of the photoreceptor drum (32) with light through a slit-shaped irradiation window (71b). Also, the irradiation window (7
Both ends of the photoreceptor drum (3) are made of felt.
2) A cleaner (77) is attached that cleans both ends and also serves as a brake for rotation. On the other hand, a supply port (78) for supplying toner into the developing device (36) is formed on the rear end side of the covering cover (71). The toner hopper (79) can be opened by contact with the toner hopper (79), and when the toner hopper (79) is removed, the toner hopper (79) is biased by a spring (not shown) and is attached to the closed state. Furthermore, (75a) and (75b) are the covering covers (75a) and (75b).
1) Through holes (80a), (80b), (80c) formed in the side frames (82a), (82b)
, (80d) is a hole for screwing.

Next, the developing device (36) will be described in detail. (8t) is a developing roller, and the distance from the photosensitive drum (32) is approximately 2.
(mm), the side frame (82a), (
Inside the aluminum sleeve (83) which is a sleeve-shaped conductive roller with a diameter of 30 (m-) of the developing roller (81) supported by the developing roller (82b), there is a three-pole magnetized magnetic roller (84). The photoreceptor drum (
32), the first pole (84a) that is substantially opposite to the magnet has a magnetic force of 95
0 to 1050 (G), and this first pole (84a)
At an interval of 75 degrees clockwise from the magnetic cuff 00 (G)
The second pole (84b) of the magnetic force SOO[G], the third pole (84b) of the magnetic force SOO[G]
c). Further, at the drive side end of the developing roller (81), as shown in FIG.
A flange (86) supporting the aluminum sleeve (85) is press-fitted to maintain good electrical continuity between the aluminum sleeve (83) and the conductive shaft (85). The center of the conductive shaft (85) is brought into point contact by a spring (88a) supported by the main frame (87).
A power supply blade (88) that applies a developing bias to the aluminum sleeve (83) by a power supply (88b) is in contact with the power supply blade (88). Note that (90) is a bearing that supports the conductive shaft (85) in the side frame (82);
1) is the first gear for rotating the aluminum sleeve (83) via the conductive shaft (85). Next (92) is a developing roller (8) at the lower end of the developing container (93).
It is a doctor blade that is provided with a gap of about 1.8 (mm) from 1), and the attachment made of plastic is fixed with a screw (94) that is a member. The tip of the doctor blade (92) is attached to the magnetic roller (8).
4), which is the intermediate part between the second pole (g4b) and the third pole (84c), where the lines of magnetic force are almost parallel to the developing roller (81), and the magnetism due to the developer consisting of negative polarity toner and carrier. A brush (not shown) is positioned so as to be approximately parallel to the 1gl image roller (81). Therefore, even if the height of the magnetic brush is regulated by the doctor blade (92), the stress on the developer can be made relatively small, which in turn reduces the driving torque required to rotate the aluminum sleeve (83). I try to do that. The screw (93) is the developer container (93).
The leaked developer adheres to the exposed part of the screw (91) inserted from the outside of Ifft container 3), and this adhered developer is further influenced by the magnetism of the magnet roller (84) and forms a column. In order to prevent the risk of contact with the main body (10) of the cassette 1 and the risk of leakage of the developing bias current, it is made of an insulating and non-magnetic plastic material.

Next, (100) and (101) move the developing roller (81) while stirring the developer (not shown) in the developing container (93).
) of non-magnetic conductive material (SUS30
4 (stainless steel)]. The first spiral (100) adjacent to the developing roller (81) has an outer diameter of 1B (
It has a shape in which a continuous spiral first blade (loOa) of mm) is wound around a first spiral shaft (100b).

On the other hand, the second spiral (101), which is separated from the first spiral (100) by a partition wall (103) made of an aluminum plate with a thickness of 0.8 (mm), has a minimum outer diameter of 24 mm.
A plurality of second blades (iotas) in the shape of an elongated circular plate (mm) cut in half are connected to a second spiral shaft (
LOlb) so that the directions alternate by half a turn. That is, in the second spiral (101), new toner supplied from the supply port (78) is sufficiently stirred with the developer in the developer container (93), while the new toner is mixed in the first spiral (100). If so, the second spiral (1
Although it does not have as much stirring power as 01), it has almost the same conveying power as the second spiral (101), although it has a small diameter. Note that the first and second spirals (100
) and (101) are for preventing the spirals (100) and (101) from being magnetized by the magnetic field of the developing roller (81) and inhibiting the movement of the developer.

Made of 5US304 [stainless steel], a non-magnetic conductive material. In addition, a supply port (78) is provided at the interval jfi (103).
) and the second spiral (lot
) side to the first spiral (100) side. Note that the height of the partition wall (103) is the same as that of the developing roller (81) after development.
), it is necessary that the developer to be dropped onto the first spiral (100) does not jump over to the second spiral (101) side. This is to prevent the amount of developer on the second spiral (101) side from increasing due to the developer jumping from the developing roller (81) to the second spiral (101) side. Furthermore, each spiral shaft (100b) is provided at the drive side end of the first spiral (100) and the second spiral (101).

(lolb) is supported by the side frame (82) via a bearing (not shown), and the drive from the main motor (not shown) of the main body is transmitted to the end of the first spiral shaft (toob). A gear (104) is attached to the end of the second spiral shaft (101b), and a second gear (106) that meshes with the gear (104) is attached to the end of the second spiral shaft (101b). Furthermore, the gear (104) has a first gear (
A third gear (107) which rotates the aluminum sleeve (83) is meshed with the third gear (107). Also gear (
104) A cylindrical part (104a) is provided at the end, which is an identification number for each individual unit, and a 13-bit barcode-like binary pattern is printed on it to identify 8192 units. A sticker (108) is attached.

The binary pattern on this sticker (1013) is read by a photoelectric sensor (not shown) installed on the main body side and consisting of a light emitting diode and a phototransistor. On the other hand, a storage section (not shown) in the control section (55) that does not disappear even when the power switch (21) is turned off stores the identification number read by the photoelectric sensor (not shown) and also stores the identification number read by the photoelectric sensor (not shown). memorizes the number of sheets printed in the unit,
The remaining lifespan of each unit is determined, and when the number of prints reaches the preset lifespan, the controller (55
) to display that fact on the control panel (27).

Next, the photoreceptor drum (32) will be described in detail. Flanges are fitted into both ends of the photoreceptor drum (32), and a leaf spring (I
ll) is provided. In addition, a spring clutch (112) which is a one-way clutch is provided, and the drive transmission unit (
109) is formed. Furthermore, a protrusion (11) provided around the central hole (110a) of the flange (110)
0b) is a bearing (
113).

-6 On the main body side, a drive shaft (114) connected to a main motor (not shown) is provided, and when the unit (31) is attached to the main body, the drive shaft (114) is connected to the flange (110). is inserted into the hole (110a) and fitted into the spring clutch (112), so that its drive can be transmitted to the photosensitive drum (32) via the flange (110), and comes into contact with the leaf spring (111); It will be electrically connected to the photosensitive drum (32). The photoreceptor drum (32) is mounted on a fit roller (8) within the unit (31).
1) with a gap of about 2 (mm),
The gap between the tip of the covering cover (71) and the frame (7
The gap between the member (116) provided at the tip of the developer member (116) for preventing scattering of the developer is approximately 0.3 (mm). Furthermore, (117) is a protective cover made of plastic, and the - side is a slit (7) formed in the covering cover (71).
4) and the other side is inserted into the first part of the frame (70).
A slit (70c) formed in the upper part of the guide (70a)
), and is worn when transporting the unit (31) and when inserting and removing it from the main body, but is removed after the unit (31) is installed.

Further, (118a) and (118b) are pins inserted from the side frame (120) on the non-driving side of the unit (31) to seal the developer in the developer container (93) during transportation. ) is attached to the main body (10) and then removed. Note (121a), (121b)
, (121c) is the unit (31) in the main body (10)
This is a hole into which a pin (not shown) on the main body side is inserted for positioning.

Next, we will discuss the operation. When the power switch (21) of the main body (10) is turned on, the control section (55) controls the main body (10) while rotating the drive source (not shown) for a certain period of time.
Check the condition of each part, and if there is any abnormality, turn on the warning lamp (not shown) on the control panel (27), etc.
Display this to the operator. -If there is no six person status,
The control unit (55) controls the heat roller (
The heater (SOa) built in the heat roller (50) is turned on until the temperature detected by the thermistor (sob) reaches 220 [°C], and the temperature of the heat roller (50) reaches 220 [°C].
When the temperature of the heat roller (50) drops to 180 ('C), the heater (50a) is turned on again and the bee 1-roller (50) is turned on. While the heater (50a) blinks repeatedly to maintain the temperature between 180°C and 220°C, the control panel ( 27) displayed on the computer and communicated to the host system (not shown).

In this state, a command to start printing is sent from the host system (not shown) and printing is started.

The control unit (55) first operates a mirror motor drive circuit (not shown) to rotate the mirror motor (61).

And the polygon mirror (62) has a constant rotation speed of 60
When the rotation becomes stable at 00 [7 minutes of rotation], the mirror motor drive circuit (not shown) transmits this to the control section (55).

Thereafter, the control unit (55) operates a main motor drive circuit (not shown) to rotate the main motor (not shown) and rotate the drive shaft (114) to rotate the photoreceptor drum (32). while rotating the other developing roller (
81) and so on. At the same time, the control section (55) operates the charging device a (33), the static eliminating device (37), and the like. As a result, the photoreceptor drum (32)
As it rotates in the direction of arrow S, it is first uniformly negatively charged by the charging device (33) so that the surface potential becomes 600 (V). On the other hand, in the laser optical system (34), a laser beam (60a) is emitted from a laser diode (60) based on print data from a host system (not shown).
) is focused by a collimator lens or compressor lens (not shown), and then enters a polygon mirror (62) that is stably rotated at 6000 [rotation time: 7 minutes] so that it is scanned in the longitudinal direction of the photoreceptor drum (32). be done. The laser beam (60a) reflected by the polygon mirror (62)
) is irradiated onto the photoreceptor drum (32) uniformly charged to about 600 (V) through the lens system (63), forming an electrostatic latent image on the photoreceptor drum (32). . However, in the lens system (63), the laser light (60a) from the polygon mirror (62) is focused into a spot of about several tens of microns and irradiated onto the photosensitive drum (32). Thereafter, the photosensitive drum (32) having the electrostatic latent image reaches the developing device (36) as it rotates, but the developing device (36)
Developing and cleaning are performed as follows.

That is, in the developer container (93), the first spiral (100) is connected to the gear (104) and the second gear (106) to which the drive from the main motor (not shown) is transmitted.
and the second spiral (tog) is rotated in the direction of the arrow and the direction of the arrow U, respectively, and the third gear (107
) is rotated by the gear (104) through the first gear (
91), the aluminum sleeve (83) is rotated in the direction of arrow V. Then, new toner is supplied onto the second spiral (101) in the developer container (93) from the toner hopper (79) through the supply port (78), and the second spiral (101) first converts it into developer. The developer is transported in the direction of arrow W within the developer container (93) while being sufficiently stirred, and the sufficiently agitated developer is supplied to the developing roller (81) side while being transported in the direction of arrow X by the first spiral (100). A magnetic brush is formed on the aluminum sleeve (83). Furthermore, a conductive shaft (85) is attached to the aluminum sleeve (83) from the power supply blade (88).
The photoreceptor drum (32
), and a bias voltage of about 400 (V) is applied. When the electrostatic latent image area of the photoreceptor drum (32) reaches the developing device (36), the toner is of negative polarity in the non-exposed area that maintains a surface potential (-) of 600 (V). , the surface potential is bias potential (-)4
Since the voltage is larger than 00 (V), there is no movement of toner from the developing roller (81) to the photosensitive drum (32) and development is not performed. However, if there is residual toner in this non-exposed area, the surface potential (-) 600 (V) and the bias potential (
-) 400 (V), the residual 1-ner is collected on the developing roller (81) side, and the photosensitive drum (32
) are cleaned. On the other hand, in the exposed area where the surface potential of the photoreceptor drum (32) is approximately 0 (V), toner is transferred to the developing roller (81) due to the potential difference between the surface potential of the photosensitive drum (32) and the developing roller (81) to which a bias voltage is applied. ) from the photoreceptor drum (32
) and development is performed. After this, the photoreceptor drum (
32) is fully exposed and exposed to light by the irradiation lamp device (76) as it rotates, after which the charge is removed.

The transfer device (37) is reached. On the other hand, in the paper feed section (24), after the main motor (not shown) is driven, the control section (55
) The paper feed roller (40) is rotated once by the paper feed signal from the paper feed cassette (23), and the uppermost sheet paper (41
) is retrieved. Then, the sheet paper (41) passes through the first sheet paper guides (42a) and (42b), operates the first lever (44b), and moves the first reed switch (41) to the first reed switch (41).
4c) from on to off, and the first paper detection device (4c) is switched from on to off.
4) After displaying on the control unit (55) that the sheet paper (41) has arrived, the aligning roller (43a) which is stopped
), it reaches (43b) and is temporarily stopped. Thereafter, the control section (55) starts driving the aligning rollers (43a) and (43b) in synchronization with the development section on the photosensitive drum (32) reaching the transfer device (37). 2
sheet paper guide (46), intermediate roller (4, 7a),
(47b), the sheet paper (41) is transferred to the transfer device (3).
7). When the developing section of the photoreceptor drum (32) and the sheet paper (41) reach the transfer device (37), a positive charge of opposite polarity to the toner is applied by the transfer device (37), and The 1-toner image is transferred to a sheet of paper (41). Next, the sheet paper (41) is peeled off from the photoreceptor drum (32) and moved to the third sheet paper guide (
48) and reaches the fixing device (52), but since the photoreceptor drum (32) is small with a diameter of about 30 (mm), the sheet paper (41) is removed without using a peeling device such as a peeling claw or a peeling charger. Photosensitive drum (32) with only stiffness
It peels off more naturally. The sheet paper (41) has a heat roller (50) whose surface temperature is between 180 ['C] and 2
After the sheet paper (41 ) is displayed on the control unit (55) by the second paper detection device (54), and the paper ejection roller (53a),
(53b) onto the paper discharge tray (2G). Then, the sheet paper (41) is detected by the second paper detection device (54).
, the second reed switch (54c)
is returned from the off state to the on state again, and the control unit (55)
It is displayed that the sheet I-paper (41) has been discharged. or,
During this time, the photosensitive drum (3) which has passed through the transfer device (37)
2) is entirely exposed to light by a static elimination lamp (38) to remove residual charges and become ready for the next printing.

When all the printing processes are completed in this way, the control section (5
5), except for temperature control of the heat roller (50), other devices are stopped and the state is in standby for the start of the first printing, after which the printing starts sequentially in response to printing commands from the host system (not shown). It becomes NJC that repeats the process. During this time, the control unit (55) stores the identification number of the unit (31) based on the binary pattern on the sticker (108) read by a photoelectric sensor (not shown), and also stores the identification number of the unit (31) every time the printing process is completed. The number of printed sheets is sequentially added to the number of printed sheets from the start of use of the unit (31). When the number of printed sheets reaches 2, which is the preset lifespan number.

The control unit (55) sends a message to that effect to the control panel (27).
to be displayed. This allows the operator to move the unit (31)
Recognizes that the unit has exceeded its usage limit, and in order to replace it with a new unit, first close the right small cover (
16) and pull out the frame (70) along the first guide (70a) and second guide (70b).

Take out the used unit (31). Sho 5 At this time,
On the drive side of the unit, a gear (104) connects the main body side gear (not shown) and a photoreceptor drum (3).
2) is a leaf spring (111) and a spring clutch (11).
, 2), but the drive shaft (114) of the spring clutch (112)
The fitting force in the axial direction of 4) is only the frictional force of the third tightening of the spring, so the leaf spring (111)
The photoreceptor drum (32) and thus the unit (31) can be inserted and removed from the drive shaft (114) relatively easily by resisting the pressing force of the spring clutch (112) and the frictional force of the spring clutch (112).

Next, the operator installs a new unit (31) with the exposed part of the photoreceptor drum (32) still covered with the protective cover (117) into the main body (10), but at this time, the operator uses the handle that was used during transportation. (72) is stored in the recess of the covering cover (71). Then, the first guide (70a) and the second guide (70b) are connected to the rail (
10a), (lob), and insert the drive shaft (114) into the flange of the photoreceptor drum (32), and the pin (not shown) on the main body side fits into the hole (
121a).

(121b) and (121c), and the unit (31) is attached to the main body (10) so that the power supply blade (88) comes into contact with the conductive shaft (85).

Furthermore, the operator selects the slits (70c), (74)
Slide the protective cover (117) along the right side cover (16) and pull it out to the outside of the main body (10) through the opening of the right small cover (16) to open the photosensitive drum (32) and make it ready for use. pin (118) to prevent scattering.
a).

(118b) is also removed, unit 1-(31) is made usable, the stone wheel cover (16) is closed, and printing is resumed. Furthermore, when the gear (104) is rotated by the drive of the main motor (not shown), a photoelectric sensor (not shown) inside the main body detects a signal on the sticker (108) affixed to the cylindrical part (104a). The binary pattern is read and the new identification number of the newly installed unit (31) is stored in the control section (55). In the control unit, the number of printed sheets for each recognition number is stored in sequence according to the printing. For example, even if a unit that has already reached the end of its lifespan is accidentally reinstalled into the main unit, it will be recognized immediately. When the number is read, the control unit (55) recognizes that the unit has been used by printing the number of sheets that can be used for the lifespan.
A message to that effect will be displayed on the control panel (27). In addition, the removed storage cover (117) should be used again when attaching or detaching the unit (31) during maintenance.
Save it for attachment to step 1).

With this configuration, the number of sheets printed for each unit (31) is stored in the control section (55), and when the number of sheets printed for each unit (31) is reached, a message to that effect is displayed on the control panel (27). Mann et al.

Since the time to replace the unit (31) can be automatically and reliably recognized, the total number of replacements by the total counter at the time of replacement can be recorded in the service note etc. for each unit.
It is not necessary to check this during the next maintenance, and furthermore, there is no need for the operator to constantly check the usage status, and the operability during maintenance is significantly improved. In addition, the number of pages printed for each unit is stored and it is immediately displayed whether the unit is used or not, so there is no need to continue printing with a used unit installed by mistake. Good images can be obtained. Furthermore, since the binary pattern is provided on the rotating cylindrical portion (104a) and rotated, scanning by the photoelectric sensor is automatically performed, so there is no need for special scanning means for reading the binary pattern. , the device can be simplified.

Note that the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways, such as changing the number of lifespans of the unit.

The charging level of the image bearing member, the size and polarity of the developing bias of the developing roller, etc. can be set arbitrarily, and the diameter of the spiral can also be set as desired.
The size is not limited as long as the diameter of the first spiral is larger than the diameter of the first spiral.

Furthermore, the shape of the spiral blades can be arbitrary, and the blades of the second spiral may also be in the form of a continuous spiral like the first spiral, but in this case, the amount of developer conveyed by the first spiral and the second spiral can be changed. In order to achieve uniformity, the second spiral may be provided with blades in the opposite direction to prevent the developer from being conveyed. Furthermore, the device for identifying individual units is not a device that reads patterns using a photoelectric sensor, but a device that identifies each unit at the end of the covering cover (127) of the unit (126), as in the other modified example shown in Fig. 14. Resistance elements (128) with different values from several [Ω] to several [NΩ] are attached, while on the main body side, when the unit (126) is attached, the resistance element (128)
A resistance measuring device (not shown) is provided which is connected to the connector terminal (128a) of and reads the resistance value as a voltage.

An apparatus may be used that records the measurement results by this resistance measuring device (not shown) in a control section (not shown) and counts the number of images for each unit. Furthermore, when the printing capacity of the unit reaches its lifespan, the image formation may be stopped immediately. Further, in the embodiment, the developing device on which the unit is supported is capable of simultaneously performing development and cleaning, but is not limited thereto, and may be a device capable of performing only development.

〔Effect of the invention〕

As explained above, according to the present invention, the number of images to be formed is stored for each unit, and when the number of images that have been formed has reached the lifetime number, the operator, service person, etc. is automatically notified. unit can be replaced immediately, there is no need to constantly check the replacement time as in the past, and there is no need to manually record the total number on the total counter at the time of replacement. It is possible to prevent the risk of incorrect use of the unit due to typographical errors, etc., and it is possible to always obtain good images.

[Brief explanation of the drawing]

Figures 1 to 13 show one embodiment of the present invention; Figure 1 is an external perspective view of the main body from the front, Figure 2 is an external perspective view of the main body from the rear, and Figure 3 is the main body. Figure 4 shows the unit, A) is a schematic explanatory diagram of the inside, (B) is a partially enlarged view of (A), Figure 4 is a perspective view of the unit, and (B) is a perspective view of the cover. A perspective view showing the frame, FIG. 5 is a partial sectional view showing the developing roller and its power supply blade, FIG. 6 is a sectional view showing the unit and the rail of the main body, and FIG. 7 shows the first spiral. FIG. 8 is a partially omitted side view showing the second spiral, FIG. 9 is a schematic explanatory diagram showing the circulation of the developer in the developer container, and FIG. 10 (A) is a partially omitted side view. A schematic sectional view showing the drive side end of the photosensitive drum, FIG. 10(b) is a sectional view showing the drive transmission section, FIG. 11 is a side view showing the non-drive side of the unit, and FIG. 12 13 is a side view showing a pin for sealing the inside of the developer container, and FIG. 14 is a perspective view showing another modification. 10... Main body, 23... Paper feed cassette, 26... Paper output tray, 31
···unit. 32... Photosensitive drum, 33... Charging device, 34... Laser optical system, 36... Developing device. 37... Transfer device, 38... Static elimination lamp, 41... Sheet paper, 47a,
47b... intermediate roller, 52... fixing device, 55
...control unit, 70...frame,
71... Covering cover. 71a... Rib, 72... Handle, 76... Irradiation lamp device, 81... Developing roller, 83...
・・Aluminum sleeve, 84・Magnetic roller, 85・Conductive shaft, 88・
...Power supply blade, 92...Doctor blade, 93
...Developer container. 94... Screw, 100... First spiral, 101... Second spiral, 10
3... Bulkhead, 104... Gear,
104a... Cylindrical part, 108... Seal,
110... Flange, 111... Leaf spring, 112... Spring clutch, 114... Drive shaft, 117...
-Protective cover.

Claims (1)

[Scope of Claims] 1. In a device having a detachable and replaceable unit in the main body and forming an electrostatic latent image on an image carrier to obtain an image, a device provided in the unit identifies the unit. a resistance element that measures the resistance value of the resistance element; a resistance measurement device that measures the resistance value of the resistance element; and a resistance measurement device that totals the number of images formed by the unit according to the measurement results from the resistance measurement device, and controls the main body according to the calculation results. An image forming apparatus characterized by comprising a control section. 2. The image forming apparatus according to claim 1, wherein the unit includes an image carrier and a developing device.