Image forming apparatus

Abstract

An image forming apparatus includes a main power unit that outputs a first DC power and an auxiliary power unit that outputs a second DC power to the components of the image forming apparatus. The auxiliary power unit includes a rechargeable capacitor. A measuring unit measures performance of the capacitor and a determining unit determines performance insufficiency of the capacitor based on the measured performance and the system configuration of the image forming apparatus. The performance is, for example, changes in a capacitance of the capacitor with time. When the determining unit determines performance insufficiency of the capacitor, a control unit adjusts, for example, a use range of the capacitor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a digital copying machine according to a first embodiment of the present invention;

FIG. 2 is an enlarged transverse sectional view of fixing rollers of a fixing device shown in FIG. 1;

FIG. 3 is a block diagram of a power source of the digital copying machine shown in FIG. 1;

FIG. 4 is a block diagram of an engine control unit shown in FIG. 3;

FIG. 5 is a block diagram of an auxiliary power device shown in FIG. 3;

FIG. 6 is a flowchart of an example of a set of a capacitor-performance measurement process and a capacitor-deterioration detection process performed by a charge/discharge control unit shown in FIG. 5;

FIG. 7 is a flowchart of an example of a system-structure detection process performed by the engine control unit shown in FIG. 4;

FIG. 8 is an example of contents of a power consumption table of peripheral apparatuses that can be attached to the digital copying machine shown in FIG. 1;

FIG. 9 is a flowchart of another example of the system-structure detection process shown in FIG. 7;

FIG. 10 is an example of contents of system-structure classification table used for an operation shown in FIG. 9;

FIG. 11 is a flowchart of an example of a capacitor-performance-insufficiency determination process performed by the engine control unit shown in FIG. 4;

FIG. 12 is a flowchart of another example of the capacitor-performance-insufficiency determination process shown in FIG. 11;

FIG. 13 is a flowchart of still another example of the system-structure detection process shown in FIG. 7;

FIG. 14 is a flowchart of still another example of the system-structure detection process shown in FIG. 7;

FIG. 15 is a flowchart of another example of the set of the capacitor-performance measurement process and the capacitor-deterioration detection process shown in FIG. 6;

FIG. 16 is a flowchart of still another example of the set of the capacitor-performance measurement process and the capacitor-deterioration detection process shown in FIG. 6;

FIG. 17 is a graph of a use voltage range of the capacitor when there is no decrease in capacitor capacitance, a discharge characteristic when there is no decrease in the capacitor capacitance, a discharge characteristic when the capacitor capacitance decreases, and discharge time when a system structure of the digital copying machine is in a full system;

FIG. 18 is a graph of an example of a use voltage range of the capacitor when the system structure is minimum, where the broken line S represents a discharge characteristic of the capacitor in an initial state, the solid line R1 represents a discharge characteristic of the capacitor before adjustment of a discharge starting voltage, and the solid line R2 represents a discharge characteristic of the capacitor in a deterioration state and after the adjustment of the discharge starting voltage;

FIG. 19 is a graph of another example of a use voltage range of the capacitor when the system structure is minimum, where the broken line S represents the discharge characteristic of the capacitor in an initial state, the solid line R1 represents a discharge characteristic of the capacitor before adjustment of an extinction voltage, and the solid line R2 represents a discharge characteristic of the capacitor in a deterioration state and after the adjustment of the extinction voltage;

FIG. 20 is a graph of still another example of a use voltage range of the capacitor when the system structure is minimum, where the broken line S represents the discharge characteristic of the capacitor in an initial state, the solid line R1 represents a discharge characteristic of the capacitor before adjustment of a charge starting voltage, and the solid line R2 represents a discharge characteristic of the capacitor in a deterioration state and after the adjustment of the charge starting voltage;

FIG. 21 is a graph of a use voltage range and discharge time of the capacitor when the system structure is in a full system, where the broken line S represents the discharge characteristic of the capacitor in an initial state and the solid line R1 represents a discharge characteristic of the capacitor in a deterioration state; and

FIG. 22 is a graph of a use voltage range and discharge time of the capacitor when the system structure is minimum, where the broken line S represents the discharge characteristic of the capacitor in an initial state, the solid line R1 represents a discharge characteristic of the capacitor before adjustment of the discharge starting voltage, and the solid line R2 represents a discharge characteristic of the capacitor in a deterioration state and after a setting value of a lower-limit voltage for recharging was adjusted from 20.5 volts to 18.5 volts.

Claims

1. An image forming apparatus comprising: a first power-supply unit that outputs a first DC power;a second power-supply unit that outputs a second DC power, the second power-supply unit including a chargeable capacitor;a measuring unit that measures a performance of the capacitor; anda determining unit that determines performance insufficiency of the capacitor based on the performance measured by the measuring unit and a system configuration of the image forming apparatus.

2. The image forming apparatus according to claim 1, wherein the performance is changes in a capacitance of the capacitor with time.

3. The image forming apparatus according to claim 1, wherein the performance is changes in a time required for charging the capacitor to a predetermined voltage.

4. The image forming apparatus according to claim 1, wherein the performance is a difference between a first voltage at the time of no load on the capacitor and a second voltage at a predetermined time elapsed after starting charging of the capacitor.

5. The image forming apparatus according to claim 1, wherein the performance is a difference between a first voltage at the time of no load on the capacitor and a second voltage at a predetermined time elapsed after supplying power to the capacitor.

6. The image forming apparatus according to claim 1, wherein the performance is charged voltage of the capacitor.

7. The image forming apparatus according to claim 1, further comprising a control unit that adjusts a use range of the capacitor based when the determining unit determines performance insufficiency of the capacitor.

8. The image forming apparatus according to claim 7, wherein the control unit adjusts a discharge starting voltage of the capacitor.

9. The image forming apparatus according to claim 7, wherein the control unit adjusts an extinction voltage of the capacitor.

10. The image forming apparatus according to claim 7, wherein the control unit adjusts a target charge voltage of the capacitor.

11. The image forming apparatus according to claim 7, wherein the control unit adjusts a lower-limit voltage for recharging of the capacitor.

12. The image forming apparatus according to claim 1, further comprising a connection detection switch that is turned ON/OFF depending on the system configuration of the image forming apparatus.

13. The image forming apparatus according to claim 1, further comprising a configuration detecting unit that detects system configuration of the image forming apparatus.

14. The image forming apparatus according to claim 1, further comprising a configuration detecting unit that detects system configuration of the image forming apparatus by communicating with each of components of the image forming apparatus.

15. The image forming apparatus according to claim 1, further comprising an input receiving unit that receives input of information about the system configuration.