JPS61147267A - Calculating mechanism for life of process unit - Google Patents

Abstract

PURPOSE:To calculate the life of a process unit with good precision by providing a counter which counts up or down a prescribe value which is set according to the size of transfer paper every time transfer paper is fed and a display part on which the counted value of the counter is displayed. CONSTITUTION:The life counter 33 has its reset terminal short-circuited through a short-circuit line 36, which is broken with a pin 37 provided to a main device body 8 when the process unit 7 is mounted on the main device body 8 for the 1st time, thereby releasing the counter from being reset. A short-circuit bar 38 composed of a relay contact, etc., is interposed between the reset terminal and enable-terminal. This short-circuit bar 38 turns on the enable-terminal only when a print start signal inputted to a port IN13 of an input port 31 is turned on to allow the life counter 33 to perform counting operation. Thus, the prescribed value set according to the size of transfer paper is counted every time transfer paper is fed to calculate the life, so the precision of the life calculation is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process unit life calculation mechanism for an image forming apparatus that prints images scanned with visible light, laser light, or the like.

2. Description of the Related Art In recent years, image forming apparatuses such as electrophotographic copying machines and laser boom printers have been equipped with developing devices around the latent image carrier in order to facilitate maintenance.

There has been provided an apparatus in which a process unit for image formation is installed with a cleaner or the like, and the process unit is removably attached to the main body of the apparatus.

In order to always obtain stable images with this type of image forming apparatus, it is necessary to use the process unit under certain predetermined conditions. These conditions include the number of times the latent image carrier (photoreceptor) is used, the amount of toner consumed, etc. The photoreceptor and toner are treated as consumables and have a certain usage limit (lifespan). In other words, these consumables are designed to expire at approximately the same time under normal use.

Therefore, in this type of image forming apparatus, it is necessary to calculate the lifespan of the process unit according to the usage conditions, and to replace the process unit when the lifespan has been reached.

Therefore, conventionally, various methods have been proposed in which the number of rotations of the photosensitive drum, the number of sheets of transfer paper passing through the unit, and the number of scans of the document table are detected, and the lifespan is calculated based on these detected values. For example, JP-A-59-61854, JP-A-59-61854;
No. 7-163276, No. 58-195854, No. 5-618/19, No. 5 B-1522
See Publications No. 63 and No. 59-61851.

By the way, the conventional lifespan calculation methods basically calculate the lifespan based on one printing operation (one sheet), and the size of the transfer paper It is not compatible with . In other words, the amount of photoreceptor used in one printing operation,
The average value of toner consumption is determined, and the number of prints is counted based on this average value to calculate the lifespan. However, there are various sizes of transfer paper that are actually printed, and there are cases where the size of transfer paper is biased towards a certain type.

In such a case, there is a problem in that if the above-mentioned average value is used as a reference, there will be a difference between the actual degree of wear and the calculated value of the lifespan.

In particular, the method of counting by the number of rotations of the photosensitive drum has the problem that there is a difference in the number of rotations of the drum between song copy and multi-copy, which is not proportional to the amount consumed. In addition, the method of simply counting the number of passing transfer sheets (', l, paper jams on the way, misfeeds (') is not counted, and there is a risk that the lifespan may be calculated to be lower than the actual degree of wear.

In order to solve the problem, the process unit life calculation mechanism according to the present invention calculates a specified value set according to the size of the transfer paper every time the transfer paper passes. It is characterized by comprising a counter that adds or subtracts by 4, and a display section that displays the results of counting by this counter.

That is, the degree of wear of the latent image carrier is proportional to the charging time, exposure time, development time, transfer time, cleaning time, and erase time, and these times are determined by the size of the transfer paper. Further, the amount of toner consumed and the amount recovered by cleaning are proportional to the amount of recorded information, and the amount of recorded information is usually approximately proportional to the size of the transfer paper.

Therefore, in the present invention, the life span of a process unit is calculated more precisely based on a specified value set according to the transfer paper size. The specified value is
For example, if the transfer paper used is from A3 to A3, depending on the area ratio, 1
For the A5 version, it may be 2 Riki unds/sheet, for the A4 version, 4 Riki unds/sheet, and for the A3 version, 8 Riki unds/sheet.

Embodiment Hereinafter, an embodiment of the process unit life calculation mechanism according to the present invention will be described with reference to the accompanying drawings.

First, an outline of the image forming apparatus will be explained according to FIG. ), a residual toner cleaner (5), and a residual charge eraser (6) are arranged, and the image is shown by the arrow (b).
Exposure from any direction. The process unit (7) is an integrated unit in which the photosensitive drum (1), charger (2), developer (3), and cleaner (5) are housed in a case (7). As shown in FIG. 4, it can be attached to and detached from the front of the device body (8). The developing unit (3) is pre-stored with an amount of toner that is consumed according to the durability of the photoreceptor drum (1), and when the toner is used up, the lifespan of the unit I (7) itself is reached. In this case, it is necessary to replace the unit (7). Note that the configuration and functions of each of the image forming elements are well known, and their explanation will be omitted.

Further, calculation of the life of unit 1-(7) will be described in detail later.

On the other hand, the transfer paper is stored in the automatic paper feed cassettes (10) and (13), and the rotation of the paper feed rollers (+1) and (14) feeds the paper into one of the cassettes (] 0) and (] 3). ) are selectively fed one by one from the transport port to the transport port (12).

(15), the toner image is conveyed to the transfer section via a pair of timing rollers (16), and after the toner image is transferred, the image is fixed in a fixing device (17) and then discharged to a discharge tray (18).

As shown in Figure 1, the lifespan calculation mechanism is located in the main body of the device (8).
It is composed of a microprocessor unit (30), an input port (31,), an output port (32), a lifespan counter (33), and a lifespan display section (34). The size of the transfer paper that is the basis for calculating the lifespan (the paper feed cassette (IO
), (+3). That is, paper feed cassette 1-(10).

(13) is dedicated for each transfer paper size, and a magnet is attached as a size identification mark, for example, and the magnet is detected by a magnetic sensor when attached to the paper feed section. This detection signal is converted into a size code as shown in the left column of the table below.
3+) each baud)・(IN5)～(IN, ) and (IN
, ) to (IN+2).

The size code is microprocessor unit 1-(
30) from the output boat (32) to the life counting counter (33), where each time the transfer paper passes, that is, each time the trailing edge of the transfer paper is detected by the sensor (35), the transfer paper is Count the specified value set according to the size. The specified value is as shown in the right column of the ex-husband, and is proportional to the amount of consumption confirmed empirically according to the transfer paper size. The counted value by the counter (33) is inputted to each boat (TNo) to (IN4.) of the human support (3I), and is sent to the life display section from the output boat (32) via the microprocessor unit (30) again. (34) is input. Lifespan display unit (l) J Installed on the operation panel of the device main body (8), it displays the lifespan tj of the process unit (7) in analog or digital form and warns you of the need for replacement just before the lifespan is reached. The lifespan is determined by the counter (3).
The time-up value is stored in the microprocessor unit 1-(30) as a time-up value that can be compared with the total counted value in step 3), and this time-up value and the counted value for each transfer sheet passing by the counter (33) are always stored in the microprocessor unit 1-(30). Compare with the Brosetza Unit (30) and calculate the lifespan.

The life counting counter (33) is connected to the process unit 1-
(7), and when it is attached to the device main body (8), it is driven by the main body power supply, but the count value is not reset even when removed from the main body (8) or when the main body power is turned off. has a backup function added.

This backup can be accomplished using battery-powered, capacitor-based, or non-volatile memory devices.

Further, as shown in FIG. 3, the life counting counter (33) has a reset terminal short-circuited by a short line (36). When the process unit (7) is attached to the device body (8) for the first time, this short wire (36) is disconnected at the pin (37) (see Figure 2) provided on the device body (8), and is reset. Release.

Further, a short bar (38) composed of a relay contact or the like is interposed between the reset terminal and the enable terminal. This soyoto bar (38) is installed when the process unit (7) is attached to the main body (8) of the device, and when the print star (print star) signal input to the input port (IN13) of the input port (31) is turned on. Turn on the enable terminal to enable counting operation of the life counting counter (33).

Next, the processing procedure will be explained with reference to the flowcharts of FIGS. 4 to 6.

Overall processing procedure of the main unit (8) (J) As shown in Figure 4, when started, first step (IS) executes power-the-routine, and step (2S) executes processing such as print operation. Run, step (3s)
Execute the 5EPC routine to calculate the lifespan, and then repeat steps (2s) and (3s).

As shown in FIG. 5, the power the blue engine first reads the current count value of the counter (33) in step (Its), and determines whether the time is up or not in step (12s).
In other words, the read count value is already in the process unit (7).
It is determined whether or not the service life has been reached, and if it is rYEsJ, a warning that printing is not possible is immediately issued in step (13s). If rNOJ, return to the main route. In other words, each time the power is turned on, the process unit (7
) check whether the timer is running or not.

Processing the print is for performing normal print processing, and its explanation will be omitted.

As shown in FIG. 6, the 5EPC subroutine for lifespan calculation first determines in step (31s) whether or not it is in presit, and if it is rNOJ, it immediately returns to the main routine.

If rYEsJ, in step (32s) it waits until the rear end of the transfer paper is detected by the sensor (35). If rYEsJ is determined in this step (32s), step (3
At step 3s), the fed transfer paper size is read using the transfer paper size code signal input to the input boat (3]), and at step (34s), the counter (33) is set for each transfer paper size. Count only the specified value (see table above). Subsequently, in step (35s), the counted value is output to the human capo (31), and in step (36s), this counted value is read and stored in memory. Next, step (:t7
In step s), it is determined whether or not the time is up in the same way as in step (12s), and if rYEsJ, step (12s) is immediately performed.
39s) issues a warning that printing is not possible. This warning means that the life of the process unit 1-(7) has come to an end.

That is, in the embodiments described above, the specified value set according to the size of the transfer paper is counted each time the transfer paper passes and is used as the standard for calculating the lifespan, so that the lifespan can be calculated with considerable accuracy. In particular, if there is a paper jam or a printing error before the trailing edge of the transfer paper is detected by the sensor (35), the counter (33) will not perform the counting operation [see step (32s)], and even if a paper jam etc. occurs thereafter, it will not be counted. The action is taken. This is because exposure and development have already been completed after the trailing edge is detected, so it is necessary to shift the count.
- It can be expected that the accuracy of life calculation will be improved compared to counting only by passing through (7).

Further, in the above processing procedure, the reason why the time-up determination is executed even during the power subroutine is that the counter count value is read in the regular routine only under certain conditions. Furthermore, the reason why the counter (33) is counted during printing is [step (31s)].
Reference], it is during printing that some changes occur in the process unit (7) for which the lifespan should be calculated. Furthermore, the counting of the counter (33) is performed by 1
It only needs to be counted once for each sheet of paper, but counting in response to a paper feed signal may cause a printer error, such as a mechanical malfunction or paper jam, before the photoreceptor is exposed to light, development, etc. If such a problem occurs, there will be an inconvenience that the process will be counted even though the process uni soto is not operating at all. Therefore, executing counting when development is completed is considered to be the most suitable timing for managing the life of the process unit. Therefore, we decided to make two determinations: (1) Printing in progress and (2) Page end (development completed).

On the other hand, the short line (
36) has the effect of preventing malfunctions due to disturbance noise while the process unit (7) is on standby, that is, until it is first installed in the apparatus main body (8). In addition, the short bar (38) has the functions of preventing malfunctions caused by disturbance noise after the process unit (7) is attached to the main body (8), reducing current consumption, and prohibiting counting when paper is passed in the test mode. . Normally, operation in test mode (J is performed for individual checking of each print process, and requires only a small amount of consumption compared to operation in print mode, so by excluding counting in test mode,
It is possible to improve the accuracy of life calculation.

Furthermore, if the life counting counter (33) is started using the sheet bar (38) when the print start signal is turned on, the present invention can be easily applied to different models in which the photosensitive drum (1) has an idling operation.

On the other hand, if an addition/subtraction type is used as the life counting counter (33), if a problem such as a paper jam occurs before development and the toner is not consumed, the added value will be subtracted. This makes it possible to further improve the accuracy of life calculation.

Furthermore, if the accuracy of life calculation is to be improved, the specified value that is the basis of counting may be corrected depending on whether the transfer paper is conveyed in the vertical direction or in the horizontal direction.

Alternatively, the main body of the device (8) is usually equipped with an image density control function that can be operated by the operator or the Pissman, and the development level (toner consumption) can be varied according to this control value. It is also conceivable to correct the specified value proportionally.

As is clear from the explanation in ``Effects of the Invention'' (2), according to the present invention, the lifespan is calculated by counting the specified value set according to the size of the transfer paper each time the transfer paper passes, which is different from the conventional method. Compared to calculations of the lifespan of a process unit simply based on printing operations, as shown in FIG.

[Brief explanation of the drawing]

゛ The drawings show one embodiment of the present invention, and Fig. 1 is an overall explanatory diagram of the life calculation mechanism, Fig. 2 is an explanatory diagram of the process unit and the main body of the device, Fig. 3 is an explanatory diagram of the life counting counter, and Fig. 3 is an explanatory diagram of the life counting mechanism. FIG. 4, FIG. 5, and FIG. 6 are flowcharts showing the processing procedure. (1)... Photosensitive drum, (2)... Charger, (3)... Developing device, (5)... Transfer charcoal tag (6
) crease, (7) process unit, (8
)・Device body, (10), (] 3)・Paper cassette, (30) Microprocessor unit, (33
)...Life 31 counter, (34)...Life display section, (35) Transfer paper detection sensor. Patent Applicant Minolta Camera Co., Ltd. Agent Patent Attorney Aohaku Ao and 2 others Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In an image forming apparatus in which a process unit for image forming in which a developing device and the like are arranged around a latent image carrier is removably attached to the main body of the apparatus, regulations set according to the size of transfer paper. A process unit life calculation mechanism comprising: a counter that adds or subtracts a value each time transfer paper passes; and a display section that displays the counting result of the counter.