Image forming apparatus and method for controlling the same

• US 20030235416A1
• Filed: 06/12/2003
• Published: 12/25/2003
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Takahashi, Atsuya, Mochizuki, Masataka
• Granted Patent: US 6,931,216 B2
• Time in Patent Office: Days
• US Class Current: 399/27
• CPC Class Codes: G03G 15/0856 Detection or control means for the developer level
• CPC Class Codes: G03G 15/086 the level being measured by electro-magnetic means
• CPC Class Codes: G03G 15/0889 for agitation or stirring

Abstract

In an image forming apparatus having a toner container, the remaining amount of toner is detected by measuring a capacitance caused by a toner detector member in the toner container. It is determined wether the measured capacitance falls within a predetermined range. If it is determined that the measured capacitance falls not within the predetermined range, the measured capacitance is not used in the detection of remaining amount of toner. The present invention thus provides an image forming apparatus reliable in the detection of toner, and a method of controlling the apparatus.

Claims

1. An image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, and a detector member for detecting the amount of the developer, the image forming apparatus comprising:

a detector for detecting a value corresponding to a capacitance between the detector member and the developer supply member; and

a processor for processing the value detected by the detector,

wherein the processor determines whether the detected value falls within a predetermined range, and avoids using the detected value in the processing if the detected value corresponding to the capacitance falls not within the predetermined range.

2. An image forming apparatus according to claim 1, further comprising a plurality of detector members within the developer container, wherein the processor uses the value detected by the detector in a summing operation if the detected value falls within the predetermined range and avoids using the detected value in the summing operation if the detected value falls not within the predetermined range.

3. An image forming apparatus according to claim 2, wherein the processor clears the detected value used in the summing operation if the detected value which has been detected by the detector during a predetermined period of time falls not within the predetermined range.

4. An image forming apparatus according to claim 2, wherein the processor uses, in the summing operation, the value which has been detected by the detector during a predetermined period of time, and calculates the amount of the developer by performing an averaging operation on the summed detected value.

5. An image forming apparatus according to claim 1, wherein the detector member comprises an electrode.

6. An image forming apparatus according to claim 4, further comprising an agitating member for agitating the developer in the developer container, wherein the processor performs the averaging operation each time the agitating member performs an agitating operation.

7. An image forming apparatus according to claim 1, wherein a cartridge, into which at least both the developer supply member and the developer container are integrated, is detachably mounted.

8. A method of controlling an image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, and a detector member for detecting the amount of the developer, the method comprising the steps of:

detecting a value, corresponding to a capacitance between the detector member and the developer supply member and relating to the amount of the developer in the developer container;

determining whether the value detected in the detecting step falls within a predetermined range;

processing the value detected in the detecting step; and

controlling the processing step to avoid using the detected value if it is determined in the determining step that the detected value falls not within the predetermined range.

9. A method according claim 8, wherein the image forming apparatus comprises a plurality of detector members within the developer container, and wherein the processing step comprises using the value detected by the detector in a summing operation if it is determined in the determining step that the detected value falls within the predetermined range and avoids using the detected value in the summing operation if it is determined in the determining step that the detected value falls not within the predetermined range.

10. A method according to claim 9, further comprising the step of clearing the detected value used in the summing operation if it is determined that the detected value falls not within the predetermined range.

11. A method according to claim 10, wherein the processing step comprising averaging the summed detected value.

12. A method according to claim 11, wherein the image forming apparatus comprises an agitating member for agitating the developer in the developer container, and wherein the averaging operation is performed each time the agitating member performs an agitating operation.

13. An image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, and first and second detector members for detecting the amount of the developer, the image forming apparatus comprising:

a storage unit for storing information relating to the developer;

a first detector for detecting a value corresponding to a capacitance between the first detector member and the developer supply member;

a second detector for detecting a value corresponding to a capacitance between the second detector member and the developer supply member; and

a processor for storing the values detected by the first and second detectors, respectively,

wherein the processor avoids storing the detected values if the detected values are in a predetermined state.

14. An image forming apparatus according to claim 13, wherein the predetermined state is that one of the value detected by the first detector and the value detected by the second detector is equal to or below a predetermined threshold.

15. An image forming apparatus according to claim 13, wherein the detected value is the one that is detected when the developer container is full of the developer.

16. An image forming apparatus according to claim 13, wherein each of the first and second detector members comprises an electrode.

17. An image forming apparatus according to claim 13, wherein a cartridge, into which the developer container and the storage unit are integrated, is detachably mounted on the image forming apparatus, and

wherein the processor stores the detected value in the storage unit if the cartridge is a new one.

18. An image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, and first and second detector members for detecting the amount of the developer, the image forming apparatus comprising:

a storage unit for storing information relating to the developer;

a first detector for detecting a value corresponding to a capacitance between the first detector member and the developer supply member;

a second detector for detecting a value corresponding to a capacitance between the second detector member and the developer supply member; and

a calculator for calculating the amount of the developer in the developer container based on a plurality of values which are detected by one of the first and second detectors during a predetermined period of time,

wherein the calculator compares the plurality of values detected during the predetermined period of time with a predetermined threshold, and avoids using in the calculation of the amount of the developer any one of the plurality of values that is determined to be equal to or below the threshold.

19. An image forming apparatus according to claim 18, wherein a cartridge, into which the developer container and the developer supply member are integrated, is detachably mounted on the image forming apparatus, and

wherein the calculator calculates the amount of the developer using the plurality of detected values if the cartridge is a new one.

20. An image forming apparatus according to claim 18, wherein each of the first and second detector members comprises an electrode.

21. A method for controlling an image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, first and second detector members for detecting the amount of the developer, and a storage unit for storing information relating to the developer, the method comprising:

a first step of detecting a value corresponding to a capacitance between the first detector member and the developer supply member and a value corresponding to a capacitance between the second detector member and the developer supply member;

a second step of storing the values, detected in the first step, in the storage unit; and

a third step of avoiding storing the detected values if the values detected in the first step are at a predetermined state.

22. A method according to claim 21, further comprising a fourth step of determining whether each of the detected values is equal to or smaller than a threshold.

23. A method for controlling an image forming apparatus having a developer container containing a developer, a developer supply member for supplying the developer from the developer container to an image bearing member, first and second detector members for detecting the amount of the developer, and a storage unit for storing information relating to the developer, the method comprising:

a first step of detecting a value corresponding to a capacitance between the first detector member and the developer supply member and a value corresponding to a capacitance between the second detector member and the developer supply member;

a second step of calculating the amount of the developer within the developer container based on a plurality of values which are detected by one of the first and second detector members during a predetermined period of time;

a third step of comparing each of the plurality of values detected during the predetermined period of time with a predetermined threshold; and

a fourth step of avoiding using, in the calculation in the second step, any one of the plurality of detected values which is determined to be equal to or smaller than the predetermined threshold.

24. A method according to claim 23, wherein a cartridge, into which the developer container and the developer supply member are integrated, is detachably mounted on the image forming apparatus, and

wherein the second step comprises calculating the amount of developer using the plurality of detected values if the cartridge is a new one.