JP3414892B2 - 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 such as a copying machine, and more particularly to a technique for controlling the timing of writing image forming information in a non-volatile memory.

[0002]

2. Description of the Related Art In recent years, image forming apparatuses having high value-added functions as shown in (1) to (3) have appeared. (1) A copying machine in which usage history data such as the number of sheets used is stored in a non-volatile memory, and parameters for image forming process control are changed according to the data so that stable images can be obtained for a long period of time.

(2) A copying machine in which history data relating to a failure such as a paper jam or a self-diagnosis result error is stored in a non-volatile memory so that appropriate after-care can be received according to the stored result. (3) A copying machine in which data of operating procedures that differ according to users and objectives is stored in a non-volatile memory, and the operating procedures can be customized.

By the way, in such an image forming apparatus, the data stored in the non-volatile memory is important as image forming information, and there should be no failure such as data destruction.

[0005]

However, the writing of the image forming information to the non-volatile memory must rely on an electric means such as a microcomputer. However, during the writing operation of the non-volatile memory, a power failure or an operation error may occur. When the power supply is cut off, the writing cycle by the microcomputer may be interrupted, and abnormal data, that is, wrong image forming information may be written in the nonvolatile memory.

The present invention has been made in view of the above points, and in the image forming apparatus having the above-mentioned high value-added function, there is a problem that the power is cut off due to a power failure or an operation mistake. However, it is an object of the present invention to prevent writing of wrong image forming information in the nonvolatile memory.

[0007]

In order to achieve the above object, the present invention stores image forming information such as image forming process conditions, use history data and user setting data as shown in the functional block diagram of FIG. In the image forming apparatus equipped with the nonvolatile memory A, the zero-cross detection means B for detecting the zero-cross of the commercial power supply, and the capacitor capacity of the control system power supply line immediately after the commercial power supply is cut off are used to supply a voltage capable of operating normally to the control system. When Tc is the time that can be held, Ta is the time required to write 1 byte of data to the non-volatile memory A, and n is the number of bytes to be written, the zero cross detection timing by the zero cross detection means B and Tc> n.Ta The image forming information writing means C for writing the image forming information into the nonvolatile memory A is provided so as to satisfy the above condition.

Further, another image forming information writing means D for immediately writing the image forming information to the non-volatile memory A, an operation mode by the means D and an operation mode by the image forming information writing means C. It is desirable to provide an operation mode switching means E for switching between. In this case, the operation mode switching unit E may switch the operation mode according to the instruction content from the operation unit or automatically according to the importance of the image forming information.

In the image forming apparatus of the present invention, the time during which the voltage capable of operating normally in the control system is held by the capacitor capacity of the control system power line immediately after the commercial power supply is cut off is Tc, and one byte to the non-volatile memory A is set. When the time required for data write processing is Ta and the number of write bytes is n, the zero cross detection timing by the zero cross detection means B of FIG. 1 and Tc> n · Ta are satisfied,
Since the image forming information writing unit C writes the image forming information in the non-volatile memory A, the wrong image forming information is written in the non-volatile memory A even if there is a failure such as power failure or operation error. Will not be lost.

By the way, the writing timing (zero cross timing) to the non-volatile memory A is 5 when the commercial power source is used.
Since it is distributed at a frequency of 0 Hz or 60 Hz, it is a double frequency (100 Hz / 120 Hz) of the commercial power supply, and is 10 msec / 8 msec intervals in terms of time. When a large amount of data is written to the non-volatile memory A at such intervals, it takes a lot of time to finish writing the final data.

On the other hand, it is often necessary to write a large amount of data to the non-volatile memory A in this image forming apparatus under special circumstances such as initial value setting at the time of maintenance or introduction. In this situation, the operator who uses this image forming device has some knowledge, so the power will not be cut off due to an operation mistake, and even if the power is cut off due to an unexpected accident, the written data can be restored. Often.

Therefore, the other image forming information writing means D for immediately writing the image forming information to the non-volatile memory A, the operation mode by the means D and the operation mode by the image forming information writing means C are operated. The control efficiency can be improved by providing the operation mode switching means E which switches in accordance with the instruction content from the section or the importance of the image forming information. Further, if the switching of the operation modes is automatically switched according to the degree of importance of the image forming information, the operator's key operation on the operation unit will not be troublesome.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a block diagram showing a configuration example of a digital copying machine according to an embodiment of the present invention.

In this digital copying machine, 1 is a light source,
The scanner unit is composed of a solid-state image sensor such as a CCD and a mechanical mechanism. The scanner unit reads an image of a document, converts it into an electric signal, and sends it as an image signal to the image processing unit 2. The image processing unit 2 performs gradation processing such as dithering and image processing such as image correction on the image signal from the scanner unit 1 and sends the image signal to the printer unit (plotter unit) 3.

The printer section 3 employs an electrophotographic system and forms an image on a transfer sheet based on an image signal sent from the image processing section 2. Reference numeral 4 denotes an operation unit, which includes operation keys and a display. By operating the operation keys on the operation unit 4, the operator can specify the operation mode of the copying machine and input various data.

Reference numeral 5 denotes a control unit, which is the scanner unit 1 described above.
The operation of the image processing unit 2, the printer unit 3, and the operation unit 4 is controlled. Reference numeral 6 is a zero-cross detector, which is a commercial (AC) power supply 7
When the AC voltage input to the DC power source 9 via the main switch 8 reaches 0V (zero cross timing), it is detected and a zero cross detection signal is generated, and the signal is sent to the control unit 5.

Reference numeral 9 denotes a DC power source, which inputs an AC voltage from the commercial power source 7 via the main switch 8, converts the AC voltage into a DC low voltage, and supplies the DC voltage to each load such as the control unit 5. 10
Is a capacitor, which is used to prevent fluctuations in the DC voltage supplied to each load. Such a capacitor is always attached to the power supply line (the output side of the DC power supply or the input side of each load).

FIG. 3 is a block diagram showing an example of the configuration of the control unit 5, which comprises a CPU 11, a ROM 12, a RAM 13, a non-volatile memory 14, an I / O port 15 and the like. CP
U11 is a central processing unit that controls the entire digital copying machine. The CPU 11 performs an interrupt process described later when a zero-cross detection signal is input to the interrupt input terminal.

The ROM 12 is a read-only memory that stores control programs for operating the CPU 11 and fixed data such as data necessary for various controls. R
The AM 13 is a readable / writable memory used as a work memory or the like that is temporarily used when the CPU 11 performs data processing. It should be noted that the CPU 11, the ROM 12, and the RAM 13 are equivalent to the image formation information writing means C, shown in FIG.
D, and functions as the operation mode switching means E.

The non-volatile memory 14 is a memory that can retain data even when the power source (AC voltage supplied from the commercial power source 7) of the digital copying machine is shut off by turning off the main switch 8. In this embodiment, the battery is a battery. 14a
It uses RAM backed up by. This non-volatile memory 14 is an electrophotographic (image forming) that changes over time by using this digital copying machine.
Copier information (image forming information) such as process condition parameters, usage history data such as the number of sheets used (number of copies), data input and set by the user (user setting data)
Used to store.

The I / O port 15 controls input / output of various signals between the CPU 11 and the scanner unit 1, the image processing unit 2, the printer unit 3, and the operation unit 4. CPU11 is C
The control target is driven and the sensor signal is detected through the PU bus 16 and the I / O port 15 to control the operations of the scanner unit 1, the printer unit 3, the operation unit 4, and the CPU bus 1.
The operation of the image processing unit 2 is directly controlled via 6.

FIG. 4 is a flowchart showing an example of a main routine of a normal processing operation by the control unit 5 of the digital copying machine. This routine starts when the power is turned on, first performs initialization processing, then monitors the sensors of each control load (scanner unit 1, image processing unit 2, printer unit 3, operation unit 4 etc.) A control signal is generated at timing to perform scanner processing, image processing processing, printer processing, operation processing, and other processing.

Thereafter, if there is no change in the copying machine information, the process returns to the scanner section processing, and the same processing as described above is repeated thereafter. However, if the copying machine information changes as a result of controlling each control load, the changed copying is performed. The machine information is temporarily stored in a predetermined address of the RAM 13, the update request flag of the copier information is set, and then the process returns to the scanner process, and the same process as described above is repeated thereafter.

FIG. 5 is a flowchart showing an example of a zero-cross interrupt processing routine by the control unit 5 of the digital copying machine. This routine starts when a zero-crossing detection signal is input to the interrupt input terminal of the CPU 11 (a zero-crossing interrupt occurs). First, it is executed so that the contents of each register in the CPU 11 used in the main routine are not erased. It is saved in the stack area of the RAM 13.

Then, it is judged whether or not the update request flag of the copying machine information is set, and if it is not set, the contents saved in the stack area of the RAM 13 are immediately returned to the above registers and the respective registers are restored. After that, the process returns to the main routine.

When the update request flag of the copy machine information is set, the copy machine information stored in the RAM 13 at a predetermined address is read and written in the non-volatile memory 14 to update the copy machine information. The request flag is reset, the contents saved in the stack area of the RAM 13 are returned to the above registers, the registers are restored, and then the process returns to the main routine.

Here, when the zero-cross interrupts occur periodically, it can be considered that there is no failure of the main switch 8 or power failure, and since the control unit 5 is supplied with power, it is stored in the nonvolatile memory 14. Can be written normally and there is no data destruction. In addition, even if the power is turned off immediately after the zero-cross interrupt occurs, several tens to 100
During a time of about msec, the voltage (capacity) of the capacitor 10 allows the control unit 5 to hold a voltage at which it can operate normally. The voltage holding time is Tc.

Furthermore, the time (Ta) required to write 1 byte of data to the non-volatile memory 14 is
When a RAM backed up by a battery is used as in this embodiment, it is several μsec to several tens μsec. Although not shown in the flow chart, when the number of bytes of the write data to the non-volatile memory 14 is n (n> 0 is an integer) in the interrupt routine, a control program is assembled so as to satisfy the following equation. ing.

Tc> Ta × n Therefore, data can be normally written to the non-volatile memory 14 before the CPU 11 is stopped due to a drop in the power supply voltage when the power supply is suddenly cut off, so that data destruction does not occur.

Of course, when the zero-crossing interrupt does not occur, the control unit 5 is not supplied with power,
The CPU 11 is stopped and writing to the non-volatile memory 14 is not performed. Therefore, in any case, the power is not cut off and erroneous data is not written in the nonvolatile memory 14.

Next, a digital copying machine according to another embodiment of the present invention will be described. Since most of the hardware configuration and operation are the same as those of the above-described embodiment, only different parts will be described.

FIG. 6 shows the control section 5 of this digital copying machine.
4 is a flowchart showing an example of a main routine of a normal processing operation according to (FIG. 3). This routine turns off the power
When it reaches N, it first starts initialization processing, then monitors the sensor of each control load, generates a control signal at a predetermined timing, and performs scanner processing, image processing processing, printer processing, operation processing. , And other processing.

When the copying machine information changes as a result of controlling each control load, it is judged whether or not the storage mode flag is set, and if it is set, the operation mode is switched to the corresponding operation mode ( If it is in that operation mode, it is not necessary to switch.) After writing the changed copying machine information in the non-volatile memory 14, the process returns to the scanner section process, but if the storage mode flag is not set, the corresponding operation After switching to the mode, the changed copying machine information is temporarily stored in a predetermined address of the RAM 13,
After setting the update request flag of the copy machine information, the process returns to the scanner process.

FIG. 7 is a flow chart showing an example of a subroutine of the operation section processing shown in FIG. 6, and processing for displaying various information on the display device based on the display data sent from the control section 5 (display processing). After performing a process (key process) corresponding to the key operation on the operation unit 4 by the operator, the operation of the storage mode selection key (not shown) on the operation unit 4 is determined.

When the operation mode for immediately writing the copying machine information into the non-volatile memory 14 is selected, the storage mode flag is set and the process returns to the main routine. When the operation mode for writing to 14 is selected,
After resetting the storage mode flag, the process returns to the main routine.

Next, a digital copying machine which is still another embodiment of the present invention will be described. Since most of the hardware configuration and operation are the same as those in the first embodiment, only different parts will be described. Further, in this embodiment, it is assumed that the ROM 12 of FIG. 3 stores data indicating the importance of the copying machine information (image forming information).

FIG. 8 shows the control section 5 of this digital copying machine.
4 is a flowchart showing an example of a main routine of a normal processing operation according to (FIG. 3). This routine turns off the power
When it reaches N, it first starts initialization processing, then monitors the sensor of each control load, generates a control signal at a predetermined timing, and performs scanner processing, image processing processing, printer processing, operation processing. , And other processing.

After that, when the copying machine information changes depending on the control result of each control load, the changed importance degree of the copying machine information is referred to by referring to the data storing the importance degree of the copying machine information stored in the ROM 12. If it is determined that the copying machine information needs to be immediately written to the non-volatile memory 14 (important copying machine information such as maintenance information related to the life judgment of parts), the operation mode is switched to the corresponding operation mode. After the copying machine information is written in the non-volatile memory 14, the process returns to the scanner unit process.

Further, if the changed copying machine information can be written in the non-volatile memory 14 at the zero-cross timing (copying machine information that is not so important), the copying machine information is temporarily switched to the corresponding operation mode.
After storing in the predetermined address of AM13 and setting the update request flag of the copying machine information, the process returns to the scanner section processing.

Although the operation mode is switched according to the content of the instruction from the operation section 4 or the importance of the copying machine information, it may be switched according to other information.

The embodiments in which the present invention is applied to a digital copying machine have been described above, but the present invention is not limited to this, and other copying machines as well as printers such as laser printers, LED printers, liquid crystal shutter printers, and facsimiles can be used. The present invention can be applied to various image forming apparatuses such as apparatuses.

[0042]

As described above, according to the image forming apparatus of the present invention, the image forming information is written in the non-volatile memory within the predetermined time immediately after the zero cross of the commercial power source is detected. Even if there is a problem that the power is cut off due to such reasons, it is possible to prevent the wrong image forming information from being written in the non-volatile memory and improve the reliability.

Further, according to the present invention, the operation mode in which the image formation information is written in the non-volatile memory within a predetermined time immediately after the zero cross of the commercial power source is detected, and the operation is performed immediately when necessary. Since the mode is switched, the control efficiency can be improved. It should be noted that the operation mode can be switched according to the instruction content from the operation unit, or the operation mode can be automatically switched according to the importance of the image formation information. Key operation can be omitted.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a basic configuration of the present invention.

FIG. 2 is a block diagram showing a configuration example of a digital copying machine according to an embodiment of the present invention.

3 is a block diagram showing a configuration example of a control unit 5 in FIG.

FIG. 4 is a flowchart showing an example of a main routine of a normal processing operation by the control unit 5 in FIG.

FIG. 5 is a flowchart showing an example of a routine for zero-cross interrupt processing.

FIG. 6 is a flowchart showing an example of a main routine of a normal processing operation by a control unit of a digital copying machine according to another embodiment of the present invention.

7 is a flowchart showing an example of a subroutine of operation unit processing of FIG.

FIG. 8 is a flowchart showing an example of a main routine of a normal processing operation by a control unit of a digital copying machine according to still another embodiment of the present invention.

[Explanation of symbols]

1: Scanner unit 2: Image processing unit 3: Printer part 4: Operation part 5: Control unit 6: Zero-cross detection unit 7: Commercial power supply 8: Main switch 9: DC power supply 10: Capacitor 11: Central Processing Unit (CPU) 12: ROM 13: RAM 14: Non-volatile memory 15: I / O port 16: CPU bus

Front page continuation (72) Inventor Jun Doi 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company, Ricoh (72) Inori Tomonori Fukui 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company In Ricoh (56) Reference JP-A-7-152593 (JP, A) JP-A-8-69327 (JP, A) JP-A-5-53386 (JP, A) (58) Fields investigated (Int.Cl . ⁷ , DB name) G03G 21/00 370-540 G03G 21/14 G06F 1/30 G06F 3/12

Claims (4)

(57) [Claims] 1. An image forming apparatus having a non-volatile memory for storing image forming information such as image forming process conditions, usage history data, user setting data, and the like, and a zero cross detecting unit for detecting a zero cross of a commercial power supply, and the commercial unit. Immediately after the power is turned off, the time during which a voltage capable of operating normally in the control system can be held by the capacitor capacity of the control system power line is Tc, and 1 is given to the nonvolatile memory.
When the time required for writing data of bytes is Ta and the number of bytes to be written is n, the zero-cross detection timing by the zero-cross detection means and Tc> n.Ta
An image forming apparatus for writing the image forming information to the nonvolatile memory so as to satisfy the above condition. 2. The image forming apparatus according to claim 1,
Other image forming information writing means for immediately writing the image forming information to the non-volatile memory when necessary, and operation mode switching means for switching the operation mode by the means and the operation mode by the image forming information writing means. An image forming apparatus comprising: 3. The image forming apparatus according to claim 2, wherein the operation mode switching unit is a unit that switches the operation mode according to an instruction content from an operation unit. 4. The operation mode switching means is means for automatically switching the operation mode switching according to the importance of the image forming information.
The image forming apparatus described.