Claims
- 1. An image forming apparatus, comprising:
- an endless image carrier which is provided movably in a moving direction, said image carrier including an outer surface having photoconductivity and a transparent inner surface which permits light to pass therethrough so as to cause the photoconductivity of said outer surface;
- a charger which is provided on an outer space of said image carrier, said charger contacting with said outer surface for applying a predetermined voltage, which is sufficient for forming latent image onto said image carrier, to said outer surface;
- an exposure unit which is provided on an inner space surrounded by the image carrier to confront the inner surface of the image carrier, and is located at a downstream side of said charger with respect to the moving direction of said image carrier, for forming an electrostatic latent image onto said outer surface of the image carrier by exposing with light the image carrier charged by the charger;
- a developing device which is provided on the outer space of said image carrier, and is located at a downstream side of said exposure unit with respect to the moving direction of said image carrier, for selectively sticking toner particles to said electrostatic latent image formed by the exposure unit; and
- a transferring device which provided on the outer space of said image carrier, and is located at a downstream side of said developer with respect to the moving direction of said image carrier, for transferring said toner image formed by the developing device from the image carrier to a recording medium,
- wherein no cleaner is provided for the image carrier between the transferring device and the charger.
- 2. The image forming apparatus of claim 1, wherein said electrostatic latent image carrier is chargeable by exposure to a voltage from said charges.
- 3. An image forming apparatus comprising:
- an image carrier provided movably in a moving direction;
- a contact charger which is in contact with said image carrier to charge said image carrier to a voltage having a predetermined polarity, said voltage being high enough to form an electrostatic latent image on said image carrier;
- an image forming mechanism provided on a downstream side of said charger with respect to the moving direction, said image forming mechanism forming an electrostatic latent image on the charged image carrier; and
- a developing device provided on the downstream side of said image forming mechanism with respect to the moving direction, said developing device accommodating toner particles and having an element, said element being provided rotatably to carry a layer of the toner particles to a contact position at which said element is in contact with said image carrier through the layer with a predetermined nip width to develop the electrostatic latent image with the toner particles and to collect residual toner particles on said image carrier, said layer having a thickness of 100 .mu.m or less, said toner particles which are carried by said element being charged to a predetermined polarity same as that of the predetermined polarity of the charged image.
- 4. An image forming apparatus as claimed in claim 3, wherein said element is a sleeve that is elastically deformed at the contact position to make the nip width.
- 5. An image forming apparatus as claimed in claim 3, wherein said developing device has a regulating member which regulates the thickness of the layer.
- 6. An image forming apparatus as claimed in claim 3, wherein said developing device accommodates one-component non-magnetic toner particles.
- 7. An image forming apparatus as claimed in claim 3, wherein said contact charger is a brush charger.
- 8. An image forming apparatus as claimed in claim 7, wherein said brush charger is fixedly provided.
- 9. An image forming apparatus as claimed in claim 3, wherein said image forming mechanism includes a laser source.
- 10. An image forming apparatus as claimed in claim 3, wherein said image carrier and the toner particles are charged to a negative polarity.
- 11. An image forming apparatus as claimed in claim 3, further comprising means for forming an electrostatic force between said image carrier and said element so as to develop a portion of said image carrier where an image should be developed and to collect the residual toner particles on a portion of said image carrier where images should not be developed.
- 12. An image forming apparatus as claimed in claim 3, wherein said developing device and said charger are provided in a case which is detachably mounted in said image forming apparatus.
- 13. An image forming apparatus as claimed in claim 12, wherein said image carrier remains in said image forming apparatus when said case is removed from said image forming apparatus.
- 14. An image forming apparatus as claimed in claim 3, wherein no cleaning device other than said developing device is provided in said image forming apparatus.
- 15. An image forming apparatus as claimed in claim 3, wherein the toner particles have a diameter in a range from 3 .mu.m to 15 .mu.m.
- 16. An image forming apparatus as claimed in claim 3, wherein said element is in contact with said image carrier with a nip width of 1 mm or more.
- 17. An image forming apparatus as claimed in claim 3, wherein a velocity of said element at the contact position is greater than that of said image carrier at the contact position.
- 18. An image forming apparatus as claimed in claim 3, wherein said image forming mechanism forms the electrostatic latent image on said image carrier by irradiating light.
- 19. An image forming apparatus as claimed in claim 18, wherein a portion of said image carrier that is irradiated with the light is developed by the toner particles on said element, and residual toner particles on a portion of said image carrier that is not irradiated with the light is collected by said element.
- 20. An image forming apparatus as claimed in claim 3, wherein the apparatus is a reverse developing image forming apparatus.
- 21. An image forming apparatus as claimed in claim 3, wherein said element is a sleeve.
- 22. An image forming apparatus comprising:
- an image carrier provided movably in a moving direction;
- a contact charger which is in contact with said image carrier to charge said image carrier to a voltage having a predetermined polarity, said voltage being high enough to form an electrostatic latent image on said image carrier;
- an image forming mechanism provided on a downstream side of said contact charger with respect to the moving direction, said image forming mechanism forming an electrostatic latent image on the charged image carrier; and
- a contact developing device provided on the downstream side of said image forming mechanism, said developing device accommodating toner particles and having an element, said element being provided rotatably to carry a layer of the toner particles to a contact position at which said element is in contact with said image carrier through the layer of the toner particles with a predetermined nip width, the thickness of said layer being 100 .mu.m or less, the toner particles which are carried by said element being charged to the predetermined polarity same as that of the charged image carrier.
- 23. An image forming apparatus as claimed in claim 22, wherein said developing device has a regulating member which regulates the thickness of the layer of the toner particles carried by said element.
- 24. An image forming apparatus as claimed in claim 22, wherein said toner particles have a diameter in a range from 3 .mu.m to 15 .mu.m.
- 25. An image forming apparatus as claimed in claim 22, wherein said element is in contact with said image carrier with a nip width of 1 mm or more.
- 26. An image forming apparatus as claimed in claim 22, wherein a velocity of said element at the contact position is greater than that of said image carrier at the contact position.
- 27. An image forming apparatus as claimed in claim 22, wherein said developing device collects residual toner particles from said image carrier, and wherein no device for collecting the residual toner particles on said image carrier other than said developing device is provided in said image forming apparatus.
- 28. An image forming apparatus as claimed in claim 22, wherein said developing device accommodates one-component non-magnetic toner particles.
- 29. An image forming apparatus as claimed in claim 22, wherein said element is elastically deformed at the contact position.
- 30. An image forming apparatus as claimed in claim 22, wherein the apparatus is a reverse developing image forming apparatus.
- 31. An image forming apparatus as claimed in claim 22, wherein said element is a sleeve.
- 32. A process cartridge used in and removably attached to a body of an image forming apparatus including an image carrier and an exposing mechanism for forming a reverse electrical latent image onto said image carrier, said image carrier being provided movably in a moving direction, said process cartridge comprising:
- a contact charger for contacting an image carrier to charge said image carrier to a voltage having a predetermined polarity, said voltage being high enough to form an electrical latent image on said carrier; and
- a developing device accommodating toner particles and having an element which is for contacting said image carrier at a contact position through a layer of the toner particles with a predetermined nip width, said element being provided rotatably to carry the layer of the toner particles to a contact position, the thickness of said layer being 100 .mu.m or less, the toner particles which are carried by said element being charged to a predetermined polarity same as that of the charged image carrier.
- 33. A process cartridge as claimed in claim 32, wherein said developing device is for developing the latent image on said image carrier and for collecting residual toner held on said image carrier.
- 34. A process cartridge as claimed in claim 32, wherein said image carrier is mounted on said body of said image forming apparatus, and said contact charger and said element are in contact with said image carrier only when said process cartridge is attached to said body of said image forming apparatus.
- 35. A process cartridge as claimed in claim 32, wherein said element is a sleeve.
- 36. A process cartridge used in and removably attached to a body of an image forming apparatus including an image carrier and an exposing mechanism for forming an electrical latent image on said image carrier, said image carrier being provided movably in a moving direction, said process cartridge comprising:
- a contact charger for contacting an image carrier to charge said image carrier to a voltage high enough to form an electrical latent image on said image carrier; and
- a developing device accommodating toner particles and having an element which is for contacting said image carrier at a contact position through a layer of the toner particles with a predetermined nip width, said element being provided rotatably to carry the layer of the toner particles to a contact position, the thickness of said layer being 100 .mu.m or less.
- 37. A process cartridge as claimed in claim 36, wherein said toner particles are charged to a predetermined polarity same as the polarity of the charged image carrier, and the exposing mechanism forms a reverse electrical image on said image carrier.
- 38. A process cartridge as claimed in claim 37, wherein said developing device is for developing the latent image on said image carrier and for collecting residual toner held on said image carrier.
- 39. A process cartridge as claimed in claim 36, wherein said image carrier is mounted on said body of said image forming apparatus, and said contact charger and said element are in contact with said image carrier only when said process cartridge is attached to said body of said image forming apparatus.
- 40. A process cartridge as claimed in claim 36, wherein said element is a sleeve.
- 41. A developing device, which is used in an image forming apparatus including a contact charger which is in contact with an image carrier to charge said image carrier to a voltage sufficient for forming an electrical latent image on said image carrier and an exposing device for forming an electrical latent image on said image carrier charged by said contact charger, for developing the electrical latent image on the image carrier by toner particles, said developing device comprising:
- a cylindrical film-like sleeve, for carrying the toner particles to a contact position at which position said sleeve is in contact with said image carrier, said sleeve having a thickness sufficient for elastic deformation and being elastically deformed at the contact position to form a predetermined nip width;
- wherein said sleeve transports the toner particles in a form of a layer with a thickness of 100 .mu.m or less.
- 42. A developing device as claimed in claim 41, wherein said sleeve is made of nickel.
- 43. A developing device as claimed in claim 41, wherein a thickness of said sleeve is about 35 .mu.m.
- 44. A developing device as claimed in claim 41, wherein said predetermined nip width is 1 mm or more.
- 45. A developing device for developing a latent image formed on an image carrier, comprising:
- an element for contacting the image carrier at a contact position, provided rotatably; and
- a regulator which regulates a thickness of a layer of toner adhered to said element to 100 .mu.m or less;
- wherein said element transports the layer of toner to the contact position and is in contact with the image carrier through the layer of toner.
- 46. The developing device as claimed in claim 45, wherein said developing device is installed in an image forming apparatus which has a contact charger for charging the image carrier to a voltage high enough to form the latent image.
- 47. The developing device as claimed in claim 45, wherein said element collects residual toner particles from the image carrier at the contact position.
- 48. A developing device as claimed in claim 45, wherein said element is a sleeve.
Priority Claims (3)
Number |
Date |
Country |
Kind |
2-122537 |
May 1990 |
JPX |
|
2-171685 |
Jun 1990 |
JPX |
|
2-171686 |
Jun 1990 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 08/088,108, filed Jul. 8, 1993, abandoned, which is a continuation of application Ser. No. 07/697,425, filed May 9, 1991 now abandoned.
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JPX |
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60-59592 |
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Continuations (2)
|
Number |
Date |
Country |
Parent |
88108 |
Jul 1993 |
|
Parent |
697425 |
May 1991 |
|