JP2998047B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus for compensating for deterioration of a photosensitive member.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, the photoreceptor is deteriorated, that is, the film thickness of the charged layer on the surface of the photoreceptor is reduced by increasing the number of printed sheets, thereby preventing a change in the charged potential. Therefore, it was necessary to adjust the value of the current and the like supplied to the charging means. For this reason, for example, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 3-209270, a storage means for writing information (for example, the number of prints) relating to the life of the photoconductor is provided, and a storage value read from this storage means by a reading means is provided. Is compared with a predetermined table value stored in advance by the control means to control the control conditions such as the current supplied to the charging means.

[0003]

However, since the apparatus disclosed in the above-mentioned publication controls the adjustment after reading the information written in the storage means as described above, many tables are required to perform fine control. Requires a large memory capacity. In addition, there is a problem that a writable and readable memory is required, resulting in an increase in cost. Therefore, an object of the present invention is to solve the above problems.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an image forming apparatus in which a photosensitive unit including at least a photosensitive member is detachable from an apparatus main body.
The apparatus main body is provided with a power supply unit for supplying a current or the like to a charging unit for charging the surface of the photoconductor to a predetermined potential, and a control unit for controlling the operation of the apparatus. The photoconductor unit includes a photoconductor unit. A first storage unit in which information relating to the life of the photoconductor unit is written. The first storage unit outputs a signal directly to the power supply unit by writing the information relating to the life of the photoconductor unit by the control unit. The unit can adjust the value of the current or the like supplied to the charging means.

[0005]

According to the image forming apparatus having such a configuration, the storage unit in which the information on the life of the photoconductor unit is written is provided in the photoconductor unit. Since the information is written, a signal is directly output to the power supply unit, and the value of the current or the like supplied by the power supply unit to the charging means can be adjusted. Therefore, the control means for controlling the operation of the apparatus reads the value written in the storage means. Without reading, it is possible to adjust control conditions such as current supplied to the charging means. For this reason, fine control is possible without requiring a large memory capacity, and it is not necessary to use a writable and readable memory as the storage means, so that an increase in the cost of the apparatus can be prevented.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram corresponding to the image forming apparatus of claim 1 of the present invention. In FIG. 1, reference numeral 11 denotes an apparatus main body of the image forming apparatus, and reference numeral 12 denotes a photoreceptor unit which is detachably attached to the apparatus main body 11 and includes at least a photoreceptor. The apparatus main body 11 is provided with a power supply unit 15 for supplying a current or the like to a charging unit 13 for charging the surface of the photoconductor of the photoconductor unit 12 to a predetermined potential, and a control unit 16 for controlling the operation of the apparatus. The photoconductor unit 12 is provided with a first storage unit 17 in which information on the life of the photoconductor unit 12 is written. The first storage means 17 stores the photosensitive unit 1 by the control means 16.
By writing the information on the life of the battery 2, it is possible to output a signal directly to the power supply unit 15 and adjust a control value such as a current supplied to the charging unit 13 by the power supply unit 15. Therefore, there is no need for the control unit 16 to read the written value in the first storage unit 17 and adjust the control value of the charging unit 13 by the power supply unit 15 in accordance with the read value.

FIG. 2 is a functional block diagram corresponding to the image forming apparatus of the present invention. In FIG.
1 is an apparatus main body, 12 is a photoreceptor unit, 13 is a charging unit, 15 is a power supply unit, 16 is a control unit, and 17 is a first unit.
This is storage means, and is the same as that of the first aspect of the present invention. Reference numeral 18 denotes a second storage unit, which is information on the life of the photoconductor unit 12 and is written with the same write value as the first storage unit 17. Reference numeral 20 denotes a discriminating unit. The discriminating unit 20 discriminates a situation such as whether the photoconductor unit 12 has been replaced with a new one by comparing the stored values of the first storage unit 17 and the second storage unit 18. be able to.

FIGS. 3 to 7 show an embodiment of the image forming apparatus according to the present invention. In FIG. 3, reference numeral 23 denotes a photosensitive drum, 24 denotes a charging roller for charging the photosensitive drum 23 (corresponding to the charging unit 13), and 25 denotes a storage element (corresponding to the first storage unit 17). The photoconductor unit 12 is detachably provided on the apparatus main body 11. The components described below are provided on the apparatus main body 11 side. Reference numeral 27 denotes an SRAM (the second storage unit 1).
8), and this SRAM 27 has a storage element 25
The information having the same value as the information on the life of the photoreceptor unit 12 is written. Reference numeral 28 denotes an EPROM, in which a control program and the like are stored. Reference numeral 30 denotes a CPU (the control means 16 and the determination means 20).
The CPU 30 performs a process control of the apparatus and various control operations based on a control program of the EPROM 28. Reference numeral 31 denotes a charging power supply unit (corresponding to the power supply unit 15). The charging power supply unit 31 supplies a current or the like for charging the photosensitive drum 23 to the charging roller 24. Further, a signal output from the storage element 25 is directly input to the charging power supply unit 31 so that the control value of the charging power supply unit 31 is adjusted.
An A / D converter 33 receives an output signal from the storage element 25, converts the signal from an analog signal to a digital signal, and inputs the signal to the CPU 30.

FIG. 4 shows the details of the charging power supply unit 31 and also shows the storage element 25 as an equivalent circuit from the viewpoint of its function. That is, the storage element 25 can be equivalently regarded as an electronic volume, and a signal value output to the charging power supply unit 31 can be varied by varying a resistance value of the electronic volume.

FIG. 5 is a diagram showing details of the storage element 25 (electronic volume).
5, a counter 36, a decoder 37, a plurality of analog switches 38, a plurality of resistors 39, and a power ON detection circuit 40. The power ON detection circuit 40 operates at the same time when the power is turned ON, and sets the counter 36 with the contents stored in the nonvolatile memory 35. Since the output of the counter 36 is connected to the decoder 37, one of the outputs corresponding to the input value of the decoder 37 is turned on, and one of the analog switches 38 corresponding to the output is turned on, and the one analog switch 38 is turned on. A resistor 39 between the switch 38 and the ground is connected to the output terminal 25a via the analog switch 38, and the charging power supply unit 31 is connected to the output terminal 25a. The output is controlled by the resistance between the control input of the charging power supply unit 31 and the ground. Counter 36 is IN
When one pulse is applied to the T input, the count 1 is added, and as the count value increases, the value of the resistor 39 changes via the decoder 37 and the analog switch 38. Power ON
When the CS input is turned on to the detection circuit 40, the counter 36
Is written into the nonvolatile memory 35.

The operation of the embodiment will be described with reference to FIGS. In FIG. 6, the power is turned on (Power On) first.
Then (step S1), an initial value processing routine (described later) is performed (step S2). Next, when it becomes possible to print (YES in step S3), processing necessary for the printing operation is performed and the printing operation is performed (step S4). When the printing operation for one page is completed (YES in step S5), the counter 3 of the storage element 25
+1 is added to the count value of No. 6 (step S6). When the count value (the number of prints) of the counter 36 reaches 500 (YES in step S7), the analog switch 38 increments the value of the resistor 39 by one step via the decoder 37 (step S8). Therefore, the storage element 25
Indicates the charging power supply unit 31 every 500 prints
, The current supplied from the charging power supply unit 31 to the charging roller 24 can be adjusted, and the deterioration of the photosensitive drum 23 can be prevented. At this time, at the same time, the SRAM
27, the stored value is incremented by the CPU 30 (step S8).

In the initial value processing routine in step S2, as shown in FIG. 7, first, the CPU 30 reads out the stored value of the life information of the photosensitive unit 12 written in the SRAM 27 (step S21), and then reads the photosensitive member. The signal from the output terminal 25a of the storage element 25 in the unit 12 is A / D converted by the A / D converter 33 (Step S22), and the value obtained by the A / D conversion is stored in Step S21.
Is compared with the value read in the SRAM 27 (step S23). If the SRAM value and the A / D conversion value are equal (YES), there is no problem, and therefore, there is no problem.
To the main routine of steps S8 to S8, and the SRAM value and A / D
If the conversion value is not equal (NO), it is determined whether the A / D conversion value is larger than the SRAM value (step S2).
4). Since it is impossible that the A / D conversion value is larger than the SRAM value, in this case (YES), it is determined that an abnormal operation has occurred, and the abnormality processing routine 1 is entered (step S25). If NO is determined in step S24, it is determined whether the A / D converted value is smaller than the SRAM value (step S26). If YES, it is determined whether the A / D converted value is smaller than the reference value N. Thereby (step S27), it is determined whether the photoconductor unit 12 is new.
That is, when the photoconductor unit 12 is new, the A / D conversion value (initial value) is zero or a value close thereto, and the reference value N is a value slightly larger than the conceivable maximum value of the initial value. Stored in the EPROM 28 in advance. A /
When the D conversion value is equal to or smaller than the reference value N (YE in step S27)
In step S), the write value of the SRAM 27 is initialized so as to be the same as the initial value (step S28), and the process proceeds to the main routine. By the way, step S2
Because it is impossible for NO to be NO in 6,
It is determined that there is a malfunction in the operation up to that point, and step S
Start over from 21. If NO in step S27, the photoconductor unit 12 is not new, so it is determined that there is something wrong, and the process proceeds to another abnormality processing routine 2 (step S29).

Storage element 2 when photoconductor unit 12 is new
The storage initial value of 5 is different in each photoconductor unit 12 due to an adjustment work to absorb the variation of the charged voltage of the photoconductor at the factory assembling process before the shipment of the photoconductor unit 12. As shown in FIG. 8, the photoreceptor unit 12 in the factory assembling process supplies a current or the like to the charging roller 24 by the charging power source 45 of the factory after the assembly, and charges the photoreceptor drum 23 by the charging roller 24. .
The photosensitive drum 2 charged by the charging roller 24
3 is detected by the surface potential sensor 46 (FIG. 9).
Step S1), the detection signal is A / D converted by the A / D converter 47 (step S2 in FIG. 9) and the CPU 48
Input. Next, assuming that the optimum value of the surface potential of the photosensitive drum 23 is 500 V, the CPU 48
It is determined whether the converted value is equal to 500 V (step S3 in FIG. 9). If NO, it is determined whether the A / D conversion value is smaller than 500 V (step S4), and if YES, the control value (counter value, resistance value, etc.) of the storage element 25 is incremented (step S5). The storage element 25 is a charging power supply 4
5, a control signal is directly input to the power supply 4 for charging.
5 supplies the adjusted current and the like to the charging roller 24 to charge the photosensitive drum 23. Then, again at steps S1 to S1
The process is repeated until S3, and when the A / D conversion value becomes equal to 500 V, the process is terminated, and the control value at that time is set as the initial value of the storage element 25 of the new photoconductor unit 12.
If NO in step S4, the A / D conversion value is 50
It is determined whether the voltage is greater than 0 V (step S7). If YES, the control value of the storage element 25 is decremented (step S8), and the routine goes to step S6.

[0014]

As described above, according to the present invention, a storage means in which information relating to the life of the photoconductor unit is written is provided in the photoconductor unit. The information about the power supply unit is directly output by writing the information about the power supply unit, and the power supply unit can adjust the value of the current and the like supplied to the charging means. It is possible to adjust the control conditions such as the current supplied to the charging unit without reading the image. For this reason, fine control is possible without requiring a large memory capacity, and it is not necessary to use a writable and readable memory as the storage means, so that an increase in the cost of the apparatus can be prevented. Further, since the correction of the initial charging characteristics of each photoconductor is facilitated, the adjustment and inspection process can be automated.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an image forming apparatus according to claim 1 of the present invention.

FIG. 2 is a functional block diagram of an image forming apparatus according to a second embodiment of the present invention.

FIG. 3 is a circuit block diagram showing an embodiment of the image forming apparatus according to the present invention.

FIG. 4 is a detailed view of a charging power supply unit and the like shown in FIG. 3;

FIG. 5 is a detailed view of the storage element shown in FIGS. 3 and 4;

6 is a flowchart mainly showing a main routine of an operation procedure of the image forming apparatus shown in FIG.

FIG. 7 is a flowchart mainly showing an initial value processing routine of an operation procedure of the image forming apparatus shown in FIG. 3;

FIG. 8 is a block diagram illustrating an apparatus during an assembling process for setting an initial value of a control value of a storage element of the photoconductor unit.

FIG. 9 is a flowchart showing an operation procedure of the apparatus of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Apparatus main body 12 Photoreceptor unit 13 Charging means 15 Power supply unit 16 Control means 17 First storage means 18 Second storage means 20 Photoreceptor drum 24 Charging roller 25 Storage element 25a Output terminal 27 SRAM 28 EPROM 30, 48 CPU 31 charging power supply unit 33, 47 A / D converter 35 non-volatile memory 36 counter 37 decoder 38 analog switch 39 resistor 40 power ON detection circuit 45 charging power supply 46 surface potential sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-209270 (JP, A) JP-A-63-132269 (JP, A) JP-A-3-2211973 (JP, A) JP-A-1- 227164 (JP, A) JP-A-3-230172 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 303 G03G 15/36 G03G 21/00 370-540 G03G 21/02-21/04 G03G 21/14 G03G 21/20 G03G 15/00 550 G03G 21/16-21/18 G03G 13/02 G03G 15/02-15/02 103

Claims (2)

(57) [Claims] A photoreceptor unit including at least a photoreceptor is provided.
In an image forming apparatus that is detachable from the main body
In the photoreceptor unit, one stored value of the number of printed sheets is stored each time a printing operation of the image forming apparatus is performed.
A first storage means for rewriting data in increments is provided, and a charging means for charging the surface of the photoreceptor to a predetermined potential is provided in the apparatus main body.
A power supply unit for supplying current, a control means for controlling a printing operation of the image forming apparatus, and a storage value of the same number of printed sheets as the first storage means.
Comparing the stored values of the second storage means with the first and second storage means.
Determining means for determining the state of the photoconductor unit
And the first storage means stores the photoconductor unit by the control means.
Information about the life of the knit is written and the power supply unit is
A signal to be output to the memory according to the stored value and the information.
By changing the voltage, the power supply unit
The value of the current value to be supplied can be adjusted .
Image forming apparatus. 2. The method according to claim 1, wherein the first storage means includes a variable resistance switch.
Memory that can switch signal output values by switching
2. The image form according to claim 1, wherein said means is used.
Equipment.