JP4329534B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a recording medium.

  In an image forming apparatus such as a laser printer or a copying machine, when outputting image data, a developer (toner) image is developed on a photosensitive drum based on the image data, and the developer image is printed on paper or the like. The image is transferred onto a recording medium and heated and pressed by a fixing device to form an image on the recording medium.

  Further, a system CPU for managing the state of the entire image forming apparatus and an engine CPU for controlling the paper transport system and the fixing device are provided in the image forming apparatus, and after the power is turned on, the system CPU and the engine CPU are started. After completion of the start-up, fixing control of the fixing device has been executed by the engine CPU. Since a predetermined time is required for heating the fixing device, a configuration for shortening the time from when the power is turned on to when an image can be formed has been conventionally considered.

For example, the fixing heater of the fixing device is provided with a first fixing heater having a capacity for normal image formation and a second fixing heater having a capacity larger than that of the first fixing heater. The second fixing heater is energized and heated rapidly, and after the start of the image forming apparatus is completed, the second fixing heater is energized to maintain the image formable state and to shorten the time until the image formable state is obtained. The structure was considered (for example, refer patent document 1).
JP 2000-330430 A

  In recent years, the system of an image forming apparatus has become larger and more multifunctional, and the program read by the system control unit has become more complicated. The load time of the program is long and it takes time to start up the system control unit. There is a tendency. For this reason, when the engine controller performs fixing control of the fixing device after waiting for the completion of activation of the system controller, the activation time of the system controller becomes very long, and the time from when the power is turned on until image formation is possible Could become longer.

  In addition, according to the conventional configuration in which the second fixing heater having a large capacity is heated until the image can be formed, it is possible to shorten the heating time of the fixing heater to the temperature at which image formation is possible. The effect of the startup time of the system control unit on the time from the start to the image formable state cannot be reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to reduce the influence of the startup time of a system control unit in an image forming apparatus, and to shorten the time from when power is turned on to when an image can be formed.

In order to solve the above problems, an invention according to claim 1 is an image forming apparatus for forming an image on a recording medium.
In an image forming apparatus for forming an image on a recording medium,
A fixing device for fixing a developer image on a recording medium by heating and pressing; and
A load unit that performs a predetermined operation without image formation;
A system CPU that controls the entire image forming apparatus;
An engine CPU for controlling the load and the heating control for heating the fixing device to a temperature at which image formation is possible;
A sub CPU having a program start time shorter than that of the engine CPU,
The sub CPU, when the program starts is completed after power on, have rows heating control until the predetermined temperature to the fixing device, after the program activation completion of the engine CPU, the heating control of up to a predetermined temperature to said fixing device Exit
The engine CPU starts heating control for heating the fixing device to a temperature at which image formation is possible upon completion of heating control up to a predetermined temperature of the sub CPU .

According to a second aspect of the invention, in the image forming apparatus according to claim 1,
When the system CPU completes the program start to a state in which a fixing control permission signal for permitting heating control to the predetermined temperature of the fixing device can be transmitted to the sub CPU, the abnormal latch state at the previous start of the image forming apparatus The fixing control permission signal is transmitted to the sub CPU based on
The sub CPU performs heating control up to a predetermined temperature on the fixing device based on a fixing control permission signal received from the system CPU.

According to the first aspect of the present invention, after the power is turned on, the sub CPU that has completed the program startup before the program startup of the system CPU and the engine CPU completes the heating control to the predetermined temperature. Fixing can be started earlier, the influence of the program start time of the system CPU can be reduced, and the time from when the image forming apparatus is turned on until the image can be formed can be shortened. Since the sub CPU finishes the heating control to the predetermined temperature to the fixing device after the engine CPU completes the program start, and the engine CPU starts the heating control to heat the fixing device to a temperature at which image formation is possible. The fixing control can be safely performed by the CPU, and the time from when the image forming apparatus is turned on to when the image can be formed can be shortened by the heating control of the fixing device by the sub CPU.

According to the second aspect of the present invention, the sub CPU performs heating control up to a predetermined temperature based on the fixing control permission signal received from the system CPU, so that the sub CPU is based on the fixing control permission signal. Thus, the fixing device can be heated and controlled safely.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

  First, the features of the apparatus of the present embodiment will be described with reference to FIG. FIG. 1 shows an internal configuration of the copying machine 100 according to the present embodiment.

  As shown in FIG. 1, a copying machine 100 as an image forming apparatus includes an operation unit 10 that receives user operation input, a system control unit 20 that manages the overall state of the copying machine 100, paper conveyance and fixing, and the like. An engine control unit 30 for controlling, a printer control unit 41 and a FAX control unit 42 controlled by the system control unit 20, an ADF (auto document feeder) 51, an FNS (finisher) 52 controlled by the engine control unit 30, The engine unit 53, the fixing device 54, and the scanner unit 55 are provided.

  The operation unit 10 includes a power switch 11. The system control unit 20 includes a system CPU 21 and a memory 22. The engine control unit 30 includes an engine CPU 31, a sub CPU 32, an OR circuit 33, and an AND circuit 34.

  The power switch 11 switches on / off of energization from a main power source (not shown) to the inside of the copying machine 100 by a user operation. The power switch 11 is, for example, a main power switch, but may include a sub power switch on the operation panel. In the configuration including the sub power switch, the power is turned on when the sub power switch is turned on while the main power switch is turned on.

  The system CPU 21 is activated when the power is turned on by the power switch 11, reads a boot program and an application program from a program memory (not shown), stores them in a RAM (not shown), and performs various operations in cooperation with the boot program and application programs in the RAM. Execute the process. Further, the system CPU 21 establishes communication with the engine CPU 31 after the start-up is completed, and manages the engine CPU 31. Further, the system CPU 21 generates a fixing control enable signal in cooperation with the boot program and transmits it to the sub CPU 32. Further, the system CPU 21 controls the printer control unit 41 and the FAX control unit 42 after the start-up is completed. The memory 22 stores data in a readable / writable manner. Further, the memory 22 stores at least abnormal latch information indicating whether or not an abnormality has occurred when the power switch 11 was previously turned off.

  The engine CPU 31 reads out various programs from a program memory (not shown), stores them in a RAM (not shown), and executes various processes in cooperation with the various programs in the RAM. Further, the engine CPU 31 establishes communication with the system CPU 21 and the sub CPU 32 after the start-up is completed. Further, the engine CPU 31 controls the ADF 51, the FNS 52, and the engine unit 53 after the activation is completed. Further, the engine CPU 31 generates a control signal for the fixing device 54 and inputs it to the OR circuit 33 after the start-up is completed.

The sub CPU 32 reads a predetermined fixing program and scan program from a program memory (not shown), stores them in a RAM (not shown), and executes a fixing process or a scan process in cooperation with the fixing program and scan program in the RAM. Further, the sub CPU 32 establishes communication with the engine CPU 31 after the activation is completed. Further, the sub CPU 32 generates a predetermined control signal for the fixing device 54 based on the fixing control permission signal input from the system CPU 21 after the activation is completed, and inputs the predetermined control signal to the OR circuit 33. In addition, the sub CPU 32 controls the scanner unit 55 after the activation is completed.

  The startup time required from the start of startup of the system CPU 21 to the completion of startup is several tens of milliseconds for the boot program and about 6 to 7 seconds for the application program. The startup time of the engine CPU 31 is about 2 to 3 seconds. The activation time of the sub CPU 32 is, for example, about several tens of milliseconds. That is, the startup time of the sub CPU 32 is extremely short, and then the startup time of the engine CPU 31 and the startup time of the system CPU 21 are increased in this order.

  The OR circuit 33 inputs a control signal as a sum of control signals input from the engine CPU 31 and the sub CPU 32 to the AND circuit 34. The AND circuit 33 inputs a control signal as a product of the control signal input from the OR circuit 33 and the fixing control permission signal to the fixing device 54.

  The printer control unit 41 performs various controls including image formation related to a printer unit (not shown) in the copying machine 100 based on the control signal input from the system CPU 21. The FAX control unit 42 performs various controls including image formation on the FAX unit (not shown) in the copying machine 100 based on the control signal input from the system CPU 21.

  The ADF 51 conveys a document when the scanner unit 45 reads an image based on a control signal input from the engine CPU 31. The FNS 52 sorts recording media such as recording paper on which an image is formed based on a control signal input from the engine CPU 31. Based on the control signal input from the CPU 31, the engine unit 53 carries the recording medium during image formation by the carry roller, and drives a photosensitive drum, a charger, a light source, an exposure unit, and the like (not shown).

  The fixing device 54 is a device that heats and pressurizes and transfers a recording medium on which a toner (developer) image is formed based on a control signal input from the CPU 31, and includes a fixing roller that pressurizes the recording medium, and the fixing A fixing heater for heating the roller, a temperature sensor for detecting the surface temperature of the fixing roller, and the like are provided. Further, the heater of the fixing device 54 may be an electromagnetic induction heating (IH) heater that has a short heating time to an image forming temperature or a halogen heater.

  The scanner unit 55 includes a CCD (Charge-Coupled Devices) as an image reading unit, a driving unit thereof, and the like. Based on a control signal input from the CPU 31, an image recorded on an original by driving the CCD is used as image data. read.

  Next, the starting operation in the copying machine 100 will be described with reference to FIG. FIG. 2 shows a timing chart of various states and various signals at the start-up of the copying machine 100, (a) shows a timing chart of the power supply state, (b) shows a timing chart of the start-up state of the system CPU 21, (c ) Shows a timing chart of the fixing control permission signal, (d) shows a timing chart of the activation state of the sub CPU 31, (e) shows a timing chart of the fixing control state of the fixing device 54, and (f) shows the engine CPU 31. (G) shows a timing chart of initial operation states of the ADF 51, the FNS 52 and the engine unit 53 as loads, and (h) shows a timing chart of an image formable state of the copying machine 100. .

  In the copying machine 100, first, as shown in FIG. 2A, the power switch 11 is turned on by the operation of the operator, and the starting operation is started. Then, as shown in FIGS. 2B, 2D, and 2F, the power switch 11 is turned on, and the system CPU 21, the engine CPU 31, and the sub CPU 32 are started. In the system CPU 21, the boot program is first read and started.

  Then, as shown in FIG. 2D, the sub CPU 32 completes startup. Further, as shown in FIG. 2B, the activation of the system CPU 21 by the boot program is completed. Then, the abnormal latch information at the previous power-off time stored in the memory 22 is read by the system CPU 21, and a fixing control permission signal based on the abnormal latch information is transmitted to the sub CPU 32. Specifically, when the abnormal latch information indicates that an abnormality has occurred when the power was turned off last time, a fixing control permission signal indicating that fixing is not permitted is transmitted to the sub CPU 32, and the abnormal latch information indicates an abnormality when the power was turned off last time. If the occurrence is not indicated, a fixing control permission signal for permitting fixing control is transmitted to the sub CPU 32. When the abnormal latch information does not indicate that an abnormality has occurred when the power is turned off last time, the fixing device 54 is not heated for safety.

  As shown in FIG. 2B, in the system CPU 21, activation by various application programs is started after completion of activation by the boot program. As shown in FIG. 2C, when a fixing control permission signal for permitting fixing control is transmitted to the sub CPU 32, as shown in FIG. 2E, fixing control for permitting fixing control is performed. Based on the permission signal, the sub CPU 32 inputs a control signal to the fixing device 54 via the OR circuit 33 and the AND circuit 34 and starts fixing control for performing predetermined heating.

  Then, as shown in FIG. 2 (f), the engine CPU 31 is completely activated. After the start of the engine CPU 31 is completed, communication between the engine CPU 31 and the sub CPU 32 is established, and peripheral circuits of the engine CPU 31 are initialized. After the communication is established, the fixing control of the fixing device 54 by the sub CPU 32 is terminated, and the engine CPU 31 Fixing control of the fixing device 54 is started, and initial control of each load of the ADF 51, FNS 52, and engine unit 53 by the engine CPU 31 is started as shown in FIG. For example, when the fixing end signal is transmitted from the sub CPU 32 to the engine CPU 31, the engine CPU 31 performs fixing control of the fixing device 54 based on the received fixing end signal.

  By the fixing control of the fixing device 54 by the sub CPU 32, for example, the surface temperature of the fixing roller of the fixing device 54 is heated to about 100 [° C.]. The initial control of each load is, for example, control until each load is brought into an image formable state.

  Then, as shown in FIG. 2E, the fixing device 54 is heated to a temperature at which an image can be formed (for example, about 200 [° C.]), and an image can be formed. Further, as shown in FIG. 2G, the engine CPU 31 initially controls the loads of the ADF 51, the FNS 52, and the engine unit 53 so that an image can be formed. Then, as shown in FIG. 2B, in the system CPU 21, activation by various application programs is completed and the activation is completely completed, and communication between the system CPU 21 and the sub CPU 32 is established, and peripheral circuits of the system CPU 21 are also established. Is initialized.

  Then, as shown in FIG. 2 (h), the system CPU 21 determines whether or not the initial control of each load and the initial control of the fixing device 54 have been completed, and when each control has been completed, the system CPU 21 The print control unit 41 and the FAX control unit 42 control the image formable state, the engine CPU 31 controls the ADF 51, the FNS 52, the engine unit 53, and the fixing unit 54, and the sub CPU 32 controls the image of the scanner unit 55. The control of the formable state is started, and the copying machine 100 is ready to form an image.

  As described above, according to the present embodiment, after the power switch 11 is turned on, the sub CPU 32 that has been activated before the activation of the system CPU 21 and the engine CPU 31 performs predetermined fixing control on the fixing device 54. The start of fixing can be accelerated, the influence of the activation time of the system CPU 11 can be reduced, and the time from turning on the power of the copying machine 100 to being ready for image formation can be shortened.

  In addition, the sub CPU 32 ends the predetermined fixing control to the fixing device 54 after the completion of the startup of the engine CPU 31, and the engine CPU 31 starts the fixing control of the fixing device 54. Therefore, the engine CPU 31 can perform the fixing control safely, and By the fixing control of the sub CPU 32, it is possible to shorten the time from when the copying machine 100 is turned on until it is ready to form an image.

  Further, since the sub CPU 32 performs predetermined fixing control on the fixing device 54 based on the fixing control permission signal received from the system CPU 21, the sub CPU 32 can safely perform fixing control based on the fixing control permission signal.

The description in the above embodiment is an example of a suitable image forming apparatus according to the present invention, and the present invention is not limited to this.
Further, the detailed configuration and detailed operation of each part constituting the image forming apparatus in the above embodiment can be appropriately changed without departing from the spirit of the present invention.

  For example, in the above embodiment, the copying machine 100 has been described as the image forming apparatus. However, the image forming apparatus is not limited to this, and may be replaced with an image forming apparatus such as a printer. Further, in the above-described embodiment, the CPU for controlling the scanner unit 55 is used as the sub CPU 32. However, the present invention is not limited to this, and a configuration in which a CPU dedicated to initial heating of the fixing device 54 is newly provided. It is good.

  In the above embodiment, in order to perform the fixing control safely, the fixing control permission signal is transmitted to the sub CPU 32 after the start of the boot program of the system CPU 21 is completed, and the sub CPU 32 fixes the fixing device based on the fixing control permission signal. However, the present invention is not limited to this, and the sub CPU 32 may automatically perform predetermined fixing control on the fixing device 54 after the start of the sub CPU 32 is completed. According to this configuration, compared to the configuration in which the fixing control permission signal is transmitted from the system CPU 21 to the sub CPU 32, the fixing control starts earlier and the time from when the power is turned on to when the image forming state is set can be further shortened.

1 is a block diagram showing an internal configuration of a copying machine 100 according to an embodiment of the present invention. 3 is a timing chart of various signals when the copying machine 100 is started up.

Explanation of symbols

100 Copier 10 Operation Unit 11 Power Switch 20 System Control Unit 21 System CPU
22 Memory 30 Engine control unit 31 Engine CPU
32 Sub CPU
33 OR circuit 34 AND circuit 41 Printer control unit 42 FAX control unit 51 ADF
52 FNS
53 Engine unit 54 Fixing unit 55 Scanner unit

Claims (2)

In an image forming apparatus for forming an image on a recording medium,
A fixing device for fixing a developer image on a recording medium by heating and pressing; and
A load unit that performs a predetermined operation without image formation;
A system CPU that controls the entire image forming apparatus;
An engine CPU for controlling the load and the heating control for heating the fixing device to a temperature at which image formation is possible;
A sub CPU having a program start time shorter than that of the engine CPU,
The sub CPU, when the program starts is completed after power on, have rows heating control until the predetermined temperature to the fixing device, after the program activation completion of the engine CPU, the heating control of up to a predetermined temperature to said fixing device Exit
The engine CPU starts heating control for heating the fixing device to a temperature at which image formation is possible when the heating control to the predetermined temperature of the sub CPU ends . When the system CPU completes the program start to a state in which a fixing control permission signal for permitting heating control to the predetermined temperature of the fixing device can be transmitted to the sub CPU, the abnormal latch state at the previous start of the image forming apparatus The fixing control permission signal is transmitted to the sub CPU based on
The image forming apparatus according to claim 1 , wherein the sub CPU performs heating control of the fixing device to a predetermined temperature based on a fixing control permission signal received from the system CPU.

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