Developing method and developing apparatus

• US 20020051142A1
• Filed: 04/27/2001
• Published: 05/02/2002
• Est. Priority Date: 05/02/2000
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Suzuki, Kazuo, Zaima, Nobuhiko, Ogata, Takao
• Granted Patent: US 6,954,285 B2
• Time in Patent Office: Days
• US Class Current: 358/1.8
• CPC Class Codes: G03G 15/065 Arrangements for controlling the potential of the developing electrode
• CPC Class Codes: G03G 15/0855 the concentration being measured by optical means
• CPC Class Codes: G03G 15/5058 using a test patch
• CPC Class Codes: G03G 2215/00042 Optical detection
• CPC Class Codes: G03G 2215/0177 Rotating set of developing units

Abstract

The present invention provides a developing method for developing a latent image formed on an image bearing member with developer including toner and carrier contained in a developer containing portion, comprising the steps of developing a first latent image for controlling a replenishing amount of the developer to the developer containing portion by a first developing electrical field, and developing a second latent image for controlling gradation of an image by a second developing electrical field, and wherein the first developing electrical field is different from the second developing electrical field.

Claims

1. A developing method for developing a latent image formed on an image bearing member with developer including toner and carrier contained in a developer containing portion, comprising the steps of:

developing a first latent image for controlling a replenishing amount of the developer to said developer containing portion by a first developing electrical field; and

developing a second latent image for controlling gradation of an image by a second developing electrical field; and

wherein

the first developing electrical field is different from the second developing electrical field.

2. A developing method according to claim 1, wherein a changed amount of density of a developed image with respect to a changed amount of density of the developer in said developer containing portion is greater in formation of the first developing electrical field than in formation of the second developing electrical field.

3. A developing method according to claim 2, wherein the first developing electrical field is provided only when an alternating electrical field is formed.

4. A developing method according to claim 2 or 3, wherein the second developing electrical field alternately includes a period during which an alternating electrical field is formed and a period during which formation of the alternating electrical field is stopped.

5. A developing method according to claim 1, wherein the developing electrical field is an alternating electrical field.

6. A developing method according to claim 1, further comprising the step of detecting information corresponding to the density of the developed image obtained by developing the first latent image, and wherein a replenished amount of the developer to said developer containing portion is controlled on the basis of the information.

7. A developing method according to claim 1, further comprising the steps of detecting information corresponding to the density of the developed image obtained by developing the second latent image, and controlling gradation of the image on the basis of the information.

8. A developing method for developing a latent image formed on an image bearing member with developer including toner and carrier contained in a developer containing portion, comprising the steps of:

developing a first latent image for controlling a replenishing amount of the developer to said developer containing portion by a first developing electrical field; and

developing a second latent image for controlling gradation of an image by a second developing electrical field; and

wherein

a changed amount of density of a developed image with respect to a changed amount of density of the developer in said developer containing portion is greater in formation of the first developing electrical field than in formation of the second developing electrical field.

9. A developing method according to claim 8, wherein the first developing electrical field is provided only when an alternating electrical field is formed.

10. A developing method according to claim 8 or 9, wherein the second developing electrical field alternately includes a period during which an alternating electrical field is formed and a period during which formation of the alternating electrical field is stopped.

11. A developing method according to claim 8, wherein the developing electrical field is an alternating electrical field.

12. A developing method according to claim 8, further comprising the step of detecting information corresponding to the density of the developed image obtained by developing the first latent image, and wherein a replenished amount of the developer to said developer containing portion is controlled on the basis of the information.

13. A developing method according to claim 8, further comprising the steps of detecting information corresponding to the density of the developed image obtained by developing the second latent image, and controlling gradation of the image on the basis of the information.

15. A developing apparatus according to claim 14, wherein a changed amount of density of a developed image with respect to a changed amount of density of the developer in said developer containing portion is greater in formation of the second developing electrical field than in formation of the first developing electrical field.

16. A developing apparatus according to claim 15, wherein the first developing electrical field is provided only when an alternating electrical field is formed.

17. A developing apparatus according to claim 15 or 16, wherein the second developing electrical field alternately includes a period during which an alternating electrical field is formed and a period during which formation of the alternating electrical field is stopped.

18. A developing apparatus according to claim 14, wherein the developing electrical field is an alternating electrical field.

19. A developing apparatus according to claim 14, further comprising the step of detecting information corresponding to the density of the developed image obtained by developing the first latent image, and wherein a replenished amount of the developer to said developer containing portion is controlled on the basis of the information.

20. A developing apparatus according to claim 14, further comprising the steps of detecting information corresponding to the density of the developed image obtained by developing the second latent image, and controlling gradation of the image on the basis of the information.

14. A developing apparatus comprising:

a developer containing portion for containing developer including toner and carrier; and

a developer carrying member for carrying the developer; and

wherein

when a latent image is formed on an image bearing member, a developing electrical field is formed between said image bearing member and said developer carrying member; and

further wherein

a first developing electrical field by which a first latent image for controlling a replenishing amount of the developer to said developer containing portion is developer is different from a second developing electrical field by which a first latent image for controlling gradation of an image.

21. A developing apparatus comprising:

a developer containing portion for containing developer including toner and carrier; and

a developer carrying member for carrying the developer; and

wherein

when a latent image is formed on an image bearing member, a developing electrical field is formed between said image bearing member and said developer carrying member; and

further comprising

a mode in which a first latent image for controlling a replenishing amount of the developer to said developer containing portion is developed by a first developing electrical field; and

a mode in which a second latent image for controlling gradation of an image is developed by a second developing electrical field; and

further wherein

a changed amount of density of a developed image with respect to a changed amount of density of the developer in said developer containing portion is greater in formation of the first developing electrical field than in formation of the second developing electrical field.

22. A developing apparatus according to claim 21, wherein the first developing electrical field is provided only when an alternating electrical field is formed.

23. A developing apparatus according to claim 21 or 22, wherein the second developing electrical field alternately includes a period during which an alternating electrical field is formed and a period during which formation of the alternating electrical field is stopped.

24. A developing apparatus according to claim 21, wherein the developing electrical field is an alternating electrical field.

25. A developing apparatus according to claim 21, further comprising the step of detecting information corresponding to the density of the developed image obtained by developing the first latent image, and wherein a replenished amount of the developer to said developer containing portion is controlled on the basis of the information.

26. A developing apparatus according to claim 21, further comprising the steps of detecting information corresponding to the density of the developed image obtained by developing the second latent image, and controlling gradation of the image on the basis of the information.