JPH11175411A - Image forming device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always and accurately execute EEPROM update by updating storage content of a memory means in accordance with a supervised result of a supervising means which supervises a prescribed signal. SOLUTION: CPUs 189 and 191 always perform serial communication with a main CPU 14 and manage a using time of each cartridge. The fall of power sources 181 and 185 which supply to each memory unit delays from a rise timing of power source of a signal processing part 4 only by a prescribed time by the actions of capacitors C1 and C2 that stabilize voltage at the time of the off of a printer and service interruption. Constants of the capacitors C1 and C2 are decided so that the prescribed time may be equal to or more than the one which is needed for the CPUs 189 and 191 to update data of EEPROMs 190 and 192. Signals 182 and 186 are voltage supervisory signals and when A/D ports of the EEPROMs 190 and 192 recognize a fact that the voltage fall data of the EEPROMs 190 and 192 from there start to be updated.

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 a control method thereof, and more particularly to an image forming apparatus for forming an image by an electrophotographic process and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic process, an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge is mounted on a main body of the image forming apparatus. A detachable process cartridge system is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a service person, so that the operability can be remarkably improved. Therefore, the process cartridge system is widely used in image forming apparatuses.

In particular, in a color laser beam printer, a process cartridge (photosensitive drum cartridge) in which an electrophotographic photosensitive member, a cleaning unit, and a waste toner container are integrated, and magenta, cyan, yellow, and black toners are contained. By making the developing cartridges for each color detachable from the image forming apparatus main body, so-called maintenance-free operation is realized.

In such an image forming apparatus, for example, when the functions of the components incorporated in the process cartridge are deteriorated due to long-term use, the entire process cartridge is replaced. This replacement operation is a very simple operation of opening the image forming apparatus main body with one touch, taking out an old process cartridge from the inside of the apparatus main body, and mounting a new process cartridge in the apparatus main body, and can be easily performed by the user himself. Things.

Further, recently, in order to further improve the usability of a user of the image forming apparatus, the following functions have been further developed, and the following functions have been provided: (1) An electronic device such as a memory is mounted on a process cartridge. Data such as manufacturing conditions are written at the time of manufacture and shipment by mounting, and when this process cartridge is attached to the image forming apparatus main body, the image forming apparatus refers to this data and performs image forming operation under the optimum conditions of the process cartridge. Function to be performed. (2) A function that detects the remaining life of the photosensitive drum during the image forming operation and stores this data in a memory so that the remaining life of the photosensitive drum can be referred to. (3) An image forming apparatus that stores diagnostic data of the image forming apparatus main body in a memory of a process cartridge and enables a service provider to promptly respond to a service by referring to the contents when an abnormality occurs or during maintenance. Self-diagnosis function. Attempts have been made to add

When the above functions are added to an image forming apparatus, it is necessary to mount an electronic device such as an EEPROM on a detachable unit such as a process cartridge. In a conventional process cartridge equipped with these electronic devices, an electronic device such as a memory and a connector are provided on a printed board, and the printed board is mounted on the process cartridge.

[0007] When the electric components are mounted on the process cartridge detachably mountable on the mounting main body, an IC such as a nonvolatile memory, for example, and the IC is protected from an external surge pulse on the printed circuit board. In general, electronic components and functional components such as diodes, resistors, capacitors, connectors, and the like are mounted on a printed circuit board.

[0008]

However, if the EEPROM is simply mounted on the process cartridge as in the conventional example described above, for example, a power failure may occur while updating the EEPROM data, or the user may erroneously change the data. If an unexpected situation such as unplugging the outlet occurs, there is a possibility that erroneous writing may occur.

[0009] Even if the EEPROM is not being updated,
Since data is not updated in the event of a power outage or disconnection of an outlet, there has been a problem that data errors increase.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem. In an image forming apparatus having a detachable cartridge having an EEPROM, the present invention relates to an EEPROM.
It is an object of the present invention to provide an image forming apparatus and a control method thereof that always accurately update the image.

[0011]

As one means for achieving the above object, the image forming apparatus of the present invention has the following arrangement.

That is, an image forming apparatus for forming an image by executing a part of the electrophotographic process by a unit detachable from the apparatus main body, wherein a memory means for storing information regarding the unit and a predetermined signal are monitored. It is characterized by comprising monitoring means, and memory control means for updating the storage contents of the memory means according to the monitoring result of the monitoring means.

For example, the monitoring means monitors a voltage level of a power supply for controlling the entire apparatus, and the memory control means, when the voltage level of the power supply falls below a predetermined value,
The storage content of the memory means is updated.

Further, there is provided a delay means for delaying the fall of the voltage level of the power supply supplied to the memory control means by a predetermined time or more than the fall of the power supply monitored by the voltage monitoring means.

For example, the predetermined time is a time required for the memory control means to update the contents stored in the memory means.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

<First Embodiment> FIG. 1 shows a typical embodiment of the image forming apparatus of the present invention, which has a resolution of 600 dots / inch (dpi), and each pixel of each color component is represented by 8 bits. FIG. 1 is a side sectional view showing a schematic configuration of a color laser beam printer (hereinafter, simply referred to as “printer”) 1 that performs image recording based on multi-valued data.

In the image forming apparatus shown in FIG. 1, the transfer paper P fed from the paper feed unit 101 by the transport means 102 or the like is held at the outer periphery of the transfer drum 103 with its leading end held between grippers 103f. At this time, the detector 8 detects the leading end of the transfer paper P, and the detection signal generates a vertical synchronization signal described later. Optical unit 10
7, an image holder (hereinafter, referred to as a “photosensitive drum”) 1
The latent images of the respective colors formed at 00 are developed by the respective color developing units Dy and D
The image is developed by c, Db, and Dm and is transferred to a sheet on the outer periphery of the transfer drum a plurality of times to form a multicolor image. afterwards,
The transfer paper P is separated from the transfer drum 103, fixed by the fixing unit 104, and discharged to a paper discharge tray 106 from a paper discharge unit 105 as a transporting unit.

Here, the developing units Dy, Dc, Db,
Dm has rotatable shafts at both ends thereof, and each is rotatably held by the developing device selecting mechanism 108 around the shaft.
Thus, as shown in FIG. 1, the developing devices Dy, Dc, Db, and Dm maintain their postures even if the developing device selection mechanism 108 rotates about the rotation shaft 110 for developing device selection. Can be kept constant. After the selected developing device is moved to the developing position, the developing device selecting mechanism unit 108 integrally moves the selecting device holding frame 109 around the fulcrum 109b with the developing device.
Is pulled toward the photosensitive drum 100 by the solenoid 109a, and moves toward the photosensitive drum 100.

Next, the color image forming operation of the printer having the above configuration will be specifically described.

First, the photosensitive drum 1 is charged by the charger 111.
00 is uniformly charged to a predetermined polarity, and the laser beam L
For example, a magenta (M) latent image is developed on the photosensitive drum 100 by the M developing device Dm on the photosensitive drum 100, and a first M toner image is formed on the photosensitive drum 100. On the other hand, the transfer paper P is fed at a predetermined timing, a transfer bias voltage (+1.8 kV) of the opposite polarity (for example, positive polarity) to the toner is applied to the transfer drum 103, and the first toner image on the photosensitive drum 100 is Is transferred onto the transfer paper P, and the transfer paper P is electrostatically attracted to the surface of the transfer drum 103. After that, the remaining M-color toner is removed from the photosensitive drum 100 by the cleaner 112 and sent to the waste toner container 180 to prepare for a latent image forming and developing process of the next color.

In this embodiment, the waste toner container 180
The photosensitive drum 100 and the charger 111 are provided in the same unit, and constitute a process cartridge (photosensitive drum cartridge) 199. The process cartridge 199 is detachably attached to the apparatus main body via the attaching means 80. Each of the color developing devices is also detachably attached to the apparatus main body as a developing cartridge.

Next, a second latent image of cyan (C) color is formed on the photosensitive drum 100 by the laser beam L, and then the second latent image on the photosensitive drum 1 is formed by the developing device Dc of C color. It is developed to form a second toner image of C color. Then, the C-color second toner image is transferred onto the transfer paper P in accordance with the position of the M-color first toner image previously transferred onto the transfer paper P. In the transfer of the second color toner image, the transfer drum 103 is charged with ++ just before the transfer paper P reaches the transfer portion.
A 2.1 kV bias voltage is applied.

Similarly, third and fourth latent images of yellow (Y) and black (Bk) colors are sequentially formed on the photosensitive drum 100, and are sequentially developed by the developing units Dy and Db, respectively. The third and fourth toner images of Y color and Bk color are sequentially transferred in alignment with the toner image previously transferred to the transfer paper P. In this way, the four color toner images are formed on the transfer paper P in an overlapping state. In the transfer of the toner images of the third color and the fourth color, ++ is applied to the transfer drum 103 immediately before the transfer paper reaches the transfer portion.
A bias voltage of 2.5 kV and +3.0 kV is applied.

The reason why the transfer bias voltage is increased every time a toner image of each color is transferred is to prevent a decrease in transfer efficiency. The main cause of this decrease in transfer efficiency is that when the transfer paper separates from the photosensitive drum 100 after the transfer, the surface of the transfer paper is charged to a polarity opposite to the transfer bias voltage by air discharge (the transfer paper carrying the transfer paper). The drum surface is also slightly charged), and this charged charge is accumulated for each transfer, and the transfer electric field is reduced for each transfer if the transfer bias voltage is constant.

In the transfer of the fourth color, when the leading edge of the transfer paper reaches the transfer start position (including immediately before and after), the transfer of the fourth toner image is performed at an effective AC voltage of 5.5 kV (frequency: 500 Hz). The DC bias voltage of the same polarity and the same potential as the transfer bias applied at that time is applied to the charger 111 while superimposing a DC bias voltage of +3.0 kV. In this way, in the transfer of the fourth color, when the leading edge of the transfer paper reaches the transfer start position, the charger 1
The reason for operating 11 is to prevent transfer unevenness. In particular, in the transfer of a full-color image, even if slight transfer unevenness occurs, the difference in color is easily conspicuous. Therefore, it is necessary to perform a discharging operation by applying a required bias voltage to the charger 111 as described above. Become.

Thereafter, when the leading end portion of the transfer paper P on which the four color toner images are superimposedly transferred approaches the separation position, the separation claw 113 is moved.
Approach, the leading end thereof comes into contact with the surface of the transfer drum 103, and the transfer paper P is separated from the transfer drum 103. The tip of the separation claw 113 keeps contact with the transfer drum surface,
After that, it separates from the transfer drum 103 and returns to the original position. As described above, the charger 111 operates from the time when the leading end of the transfer paper reaches the transfer start position of the final color (the fourth color) to the time when the rear end of the transfer paper leaves the transfer drum 111, and the accumulated charges (on the transfer paper). (The polarity opposite to that of the toner) is removed, thereby facilitating separation of the transfer paper by the separation claw 113 and reducing aerial discharge during separation. When the rear end of the transfer paper reaches the transfer end position (the exit of the nip formed by the photosensitive drum 100 and the transfer drum 103), the transfer bias voltage applied to the transfer drum 103 is turned off (ground potential). I do. At the same time, the bias voltage applied to the charger 111 is turned off. Next, the separated transfer paper P is transported to the fixing device 104, where the toner image on the transfer paper is fixed, and is discharged onto the paper discharge tray 106.

Next, the operation of forming an image by laser beam scanning in the printer of the present embodiment will be described.

In FIG. 1, reference numeral 107 denotes an optical unit, which includes a detector 9, a semiconductor laser 120, and a polygon mirror 1.
21, scanner motor 122, lens 123, mirror 1
25. When the recording paper P is fed and the leading end of the recording paper P is conveyed to the transfer drum 103, the image signal VDO for one page is synchronized with the semiconductor laser 12
0, and the light beam L modulated by the image signal VDO is emitted toward the polygon mirror 121 rotated by the scanner motor 122, and the emitted light beam L is transmitted to the photosensitive drum by the lens 123 and the mirror 125. It is led to 100. When the light beam L is emitted, the light beam L is detected by the detector 9 disposed on the main scanning axis, and a BD (beam detection) signal serving as a horizontal synchronization signal is output. As a result, the photosensitive drum 100 is scanned and exposed by the light beam L in synchronization with the BD signal, and an electrostatic latent image is formed.

The printer of this embodiment outputs an image at a resolution of 600 dots / inch (dpi) through the above-described image forming process.

As input data of this apparatus, color image data (for example, RG
This can be image data generated by another image data generating device (such as a still image recorder) and stored in some storage medium. For this purpose, as shown in FIG. 1, the apparatus is provided with a printer controller 2 for receiving image information from a host computer and generating image data, and a signal processing unit 4 for processing the image data.

In this embodiment, color image data sent from the host computer is considered as input data.

FIG. 2 is a block diagram showing a functional configuration of the printer 1 according to the present embodiment. In FIG. 2, the printer 1
Is a host computer (hereinafter referred to as “host”) 10
00 is received and expanded, and each color component is composed of 8 bits (D0 to D0).
The printer controller 2 outputs the YMCBk image signal 6 composed of 7), the printer engine 3, and a display 208 such as an operation panel. Alternatively, the host 1000 may send out bit data such as RGB read by an image reader or the like as image information 5, and in this case, the printer controller 2 processes without interpreting this.

Various image signals other than the image signal 6 are transmitted and received between the printer controller 2 and the printer engine 3 in the form of serial communication. These image signals include a page synchronization signal (PSYNC) in the sub-scanning direction sent from the printer engine 3 to the printer controller 2,
There is a synchronization signal (LSYNC) in the main scanning direction and a data transfer clock (VCLK). Printer controller 2
Outputs an 8-bit signal of each color component of the image signal 6 in synchronization with a data transfer clock (VCLK).

FIG. 3 is a block diagram showing a functional configuration of the printer engine 3 in the present embodiment. In FIG. 3, a reference clock from a reference oscillator 10 included in an optical unit 107 is frequency-divided by a dividing period 11, and a scanner is set so that a phase difference between the frequency-divided clock and a feedback signal from the scanner motor 122 becomes a predetermined phase difference. Motor 1
The motor 22 is rotated at a constant speed by the motor control circuit 12 (including a known phase control circuit not shown). Then, the rotation of the scanner motor 122 is transmitted to the polygon mirror 121 to rotate the polygon mirror 121 at a constant speed.

On the other hand, the transfer drum 103 is rotated at a constant speed by a drive motor (not shown), the leading end of the recording paper P on the transfer drum 103 is detected by the detector 8, and a vertical synchronizing signal (VSYNC) is output to the signal processing unit 4. Is output to And
VSYNC defines the leading edge of each color image. VS
After YNC is output, B generated by detector 9
The image signal (VDO) is sequentially transmitted to the semiconductor laser 120 in synchronization with the BD signal, using the D signal as a horizontal synchronization signal (HSYNC). Here, the timings of the above-described vertical synchronizing signal (VSYNC), horizontal synchronizing signal (HSYNC), and image signal (VDO) in the image forming process are as shown in FIG.

The CPU 14 incorporated in the signal processing unit 4 performs serial communication with the printer controller 2 via the communication line 15 to exchange control signals and synchronize the operations of the printer controller 2 and the printer engine 3.
Further, the CPU 14 includes the developing device memory units 203 to 20.
6 and the photosensitive drum memory unit 207 and the backup memory 230 via the serial communication line 202. Developing unit memory units 203 to 206
Includes an EEPROM attached to the developing device of each color, and the photosensitive drum memory unit 207 includes a process cartridge, that is, an EEPROM attached to the photosensitive drum cartridge.

Hereinafter, the black developing device memory unit 20
FIG. 5 shows the detailed configuration of the photosensitive drum memory unit 6 and the photosensitive drum memory unit 207 in relation to the CPU 14 in the signal processing unit 4. In FIG. 5, the memory unit 2 of the black developing device
07 and the photosensitive drum memory unit 207 (hereinafter, both are simply referred to as “memory units”)
(189 or 191), an EEPROM (190 or 192), and a capacitor (C1 or C2). Then, the signal processing unit 4 and the memory unit 20
6 and the serial communication line 202 for communicating with the memory unit 207 are connected by a detachable connector via a cable.

The transistor Q1 shown in the signal processing section 4 of FIG.
A power switch for turning off the power switch, which is controlled by a port / VCCON of the CPU 14. CPUs 189 and 191
Performs serial communication with the main CPU 14 at all times, and manages the usage time of each cartridge. 190 and 192
Is an EEPROM. The EEPROMs 190 and 192 and the CPUs 189 and 191 are connected to signals 193 to 198 and 41, respectively.
At 0, 411, information such as the usage time of each cartridge is read / updated. That is, serial communication is always performed between the main CPU 14 of the printer and the CPUs 189 and 191, and the latest information is always stored in the EEPROMs 190 and 192. Reference numerals 181 and 185 denote power supplies to be supplied to the respective memory units. When the printer is turned off or a power failure occurs, the power supply (+5 [V]) of the signal processing unit 4 rises due to the action of the capacitors C1 and C2 for stabilizing the voltage. The fall falls a predetermined time later than the fall timing. This predetermined time is determined by the CPUs 189 and 191 during the EEP.
The constants of the capacitors C1 and C2 are determined so that the time required for updating the data in the ROMs 190 and 192 is longer than the required time. Signals 182 and 186 are voltage monitoring signals of +5 [V], and this signal changes from +5 [V] to +4.5.
The CPU 189, 191 reports that the voltage has dropped to [V].
From the A / D port of the
The update of data 90, 192 is started. Of course, 4.5 [V] is merely an example, and the threshold voltage for starting the EEPROM update may be set as appropriate.

FIG. 6 shows how the photosensitive drum cartridge 199 and the photosensitive drum memory unit 207 having the above-mentioned EEPROM 192 are mounted. The photosensitive drum cartridge 199 mainly includes the photosensitive drum 100, the waste toner container 180, the EEPROM unit 207, and the screw 36.
0.

FIG. 7 shows a photosensitive drum memory unit 207.
9 is a flowchart of an EEPROM update process using the example of FIG.

First, when the power of the printer body is turned on (S701), power is supplied to the EEPROM 192 (S702), and it is confirmed that the photosensitive drum cartridge door is closed (S703). Here, a door open sensor (not shown) is used to detect the opening and closing of the door. If the photosensitive drum cartridge door is closed, it is confirmed that there is a photosensitive drum cartridge (S70).
4). This determination is made based on whether communication between the CPU 14 and the CPU 191 in the photosensitive drum memory unit 207 can be performed normally.

If there is no cartridge, the user is notified via the display 208 of the display panel or the host computer 1000 (S705). If there is a cartridge, an EEPROM 192 serving as a photosensitive drum memory is provided.
The desired information is read from (S706). In this state, the printer is in a standby state, and is in a printable state. Here, when any data error occurs during reading from the EEPROM 192 (S707),
The user is warned of the failure of the EEPROM 192 (S70).
8).

After the printing process is completed (S709), if the photosensitive drum cartridge door is not open (S710),
Next, it is determined whether or not the power supply of the signal processing unit 4 is +5 [V] but is lower than +4.5 [V] (S
711) If it remains at +4.5 [V] or more, the process returns to step S709 to be in a print waiting state.

On the other hand, if the photosensitive drum cartridge door is open in step S710, the contents of the EEPROM 192 in the photosensitive drum memory unit 207 are updated (S712), and the process waits until the door is closed (S70).
3).

In step S711, the power supply is set to +4.5.
[V] or less, it is determined that the printer has been turned off by the user or that a power failure has occurred, and the EEPROM in the photosensitive drum memory unit 207
192 is updated (S713).

The information updated in the EEPROM 192 in the photosensitive drum memory unit 207 is, for example, data such as remaining life data of the photosensitive drum 100 and accumulated use time.

Although the photosensitive drum memory unit 207 has been described as an example, the internal EEPROM is updated in the same procedure in each of the color developing memories 203 to 205 including the black developing device memory unit 206.

In this embodiment, the EEPROM is used.
Although the CPU and the CPU for controlling the EEPROM have been described as separate components, a CPU with a built-in EEPROM may of course be used. In addition, a configuration in which the operation of the present embodiment is realized by a combination of a voltage comparison circuit and a gate array instead of the CPU is also possible.

As described above, according to the present embodiment,
The power supply to the CPU for updating the data in the EEPROM incorporated in the cartridge is delayed more than the power supply of the main unit when the power supply of the printer is turned off.
By updating the data in the PROM, the memory can be reliably updated even when the power is turned off.

<Second Embodiment> Hereinafter, a second embodiment according to the present invention will be described.
An embodiment will be described. The configuration of the image forming apparatus according to the second embodiment is the same as that of the above-described first embodiment, and a description thereof will not be repeated.

In the first embodiment described above, each control CPU is provided in each memory unit,
The example in which the power supply is monitored by U has been described.
In the second embodiment, an example will be described in which a sub CPU for monitoring power is provided in the printer body.

FIG. 8 shows a configuration example according to the second embodiment. According to FIG. 8, in the signal processing unit 4, the power supply +5
The sub CPU 605 monitors the voltage of [V], and +4.
When the voltage falls below 5 [V], it is determined that the power of the printer main body is turned off or a power failure occurs, and each memory unit 60
The data of the EEPROMs 603 and 604 of the first and second memories 602 are updated.

In the example shown in FIG. 8, the sub CPU
605 updates the EEPROM data of the photosensitive drum cartridge and the developing cartridge of each color.
The capacitor C3 having a larger capacitance is required as compared with the capacitance of the capacitors (C1, C2) used for stabilizing the power supply in the first embodiment described above.

As described above, according to the second embodiment, it is possible to centrally manage each cartridge.

According to the present invention, there is provided a connector provided with an IC such as an EEPROM for use in connecting or disconnecting an electric circuit, a process cartridge and a developing cartridge having the connector, and further including the cartridge. This is applied to an image forming apparatus. Further, this connector can be suitably used in a fixing unit other than the process cartridge, an intermediate transfer unit, and the like, which are detachably formed in the image forming apparatus main body.

Here, as an image forming apparatus to which the present invention can be applied, for example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile apparatus, an electrophotographic word processor, etc. Is included.

The cartridge to which the present invention can be applied includes a charging means, a developing means or a cleaning means,
The electrophotographic photoreceptor and the electrophotographic photoreceptor may be integrally formed as a cartridge, and the cartridge may be detachable from the image forming apparatus main body, or at least one of a charging unit, a developing unit, and a cleaning unit, and May be integrated into a cartridge so that it can be attached to and detached from the main body of the electrophotographic image forming apparatus. Further, at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge and can be detachably attached to the main body of the electrophotographic image forming apparatus. May be used.

<Other Embodiments> Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (one device) For example, the present invention may be applied to a copying machine, a facsimile machine, and the like.

An object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0065]

As described above, according to the present invention, a control unit for updating data in a non-volatile memory incorporated in a cartridge detachable from a main body of the apparatus is provided.
A power supply different from that of the main body control unit is supplied, and the power supply of the main body control unit is delayed when the power supply of the main body is turned off, and the data in the nonvolatile memory is updated during that time. This makes it possible to always reliably update the memory contents in any unforeseen situation, such as when the main switch is turned off, during a power failure, or when the outlet is disconnected.

Accordingly, it is possible to more accurately perform the life prediction and the like of the consumables that can be attached to and detached from the apparatus.

[0067]

[Brief description of the drawings]

FIG. 1 is a side sectional view of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a functional configuration of a printer according to the embodiment.

FIG. 3 is a block diagram illustrating a functional configuration of a printer engine according to the embodiment.

FIG. 4 is a timing chart of each synchronization signal and an image signal in the present embodiment.

FIG. 5 is a block diagram illustrating a detailed configuration of a memory unit according to the embodiment;

FIG. 6 is a diagram illustrating a mounting state of a cartridge and a memory unit according to the present embodiment.

FIG. 7 is a flowchart illustrating an EEPROM update process according to the embodiment.

FIG. 8 is a block diagram illustrating a detailed configuration of a memory unit according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 3 printer engine 4 signal processing unit 14 CPU (printer) 203 magenta developing unit memory unit 204 cyan developing unit memory unit 205 yellow developing unit memory unit 206 black developing unit memory unit 207 photosensitive drum memory unit 189, 191 CPU (memory unit) 190 , 192 EEPROM

Claims (11)

[Claims] 1. An image forming apparatus for forming an image by executing a part of an electrophotographic process by a unit detachable from a main body of the apparatus, wherein a memory means for storing information on the unit and a predetermined signal are monitored. An image forming apparatus comprising: a monitoring unit; and a memory control unit that updates a storage content of the memory unit according to a monitoring result of the monitoring unit. 2. The monitoring means monitors a voltage level of a power supply for controlling the entire apparatus, and the memory control means, when the voltage level of the power supply falls below a predetermined value, stores the contents of the memory means. The image forming apparatus according to claim 1, wherein the image is updated. 3. The apparatus according to claim 1, further comprising delay means for delaying the fall of the voltage level of the power supply supplied to said memory control means by a predetermined time or more than the fall of the power supply monitored by said voltage monitoring means. The image forming apparatus according to claim 2. 4. The image forming apparatus according to claim 3, wherein the predetermined time is a time required for the memory control unit to update the contents stored in the memory unit. 5. The image forming apparatus according to claim 1, wherein the memory stores the information in a nonvolatile memory. 6. The image forming apparatus according to claim 1, wherein the unit is a process cartridge. 7. The image forming apparatus according to claim 1, wherein the unit is a developing cartridge. 8. The image forming apparatus according to claim 1, wherein the memory unit stores information on a life of the unit. 9. The image forming apparatus according to claim 1, wherein the monitoring unit monitors the predetermined signal using an analog / digital conversion function of a microcomputer. 10. A control method in an image forming apparatus for forming an image by executing a part of an electrophotographic process by a unit detachable from an apparatus main body, wherein: a storage step of storing information on the unit in a memory; A control method, comprising: a monitoring step of monitoring a predetermined signal; and a memory updating step of updating storage contents of the memory according to a monitoring result in the monitoring step. 11. A computer-readable memory storing a control program code in an image forming apparatus for forming an image by executing a part of an electrophotographic process by a unit detachable from an apparatus main body. A code of a storage step to be stored in the memory, a code of a monitoring step of monitoring a predetermined signal, and a code of a memory updating step of updating the storage content of the memory according to a monitoring result in the monitoring step. Computer readable memory featured.