Developing device, process cartridge and image forming apparatus that prevent toner leakage

• US 6,212,343 B1
• Filed: 10/22/1999
• Issued: 04/03/2001
• Est. Priority Date: 10/22/1998
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nagai, Kenichiroh, Osanai, Kenetsu, Hosokawa, Hiroshi, Yamanaka, Tetsuo
• Primary Examiner(s): Chen, Sophia S.
• Assistant Examiner(s): TRAN, HOAN H
• Application Number:
  US09/425,221
• Time in Patent Office: 529 Days
• Field of Search: 399/102, 399/103, 399/104, 399/105, 399/106, 399/111, 399/274
• US Class Current: 399/102
• CPC Class Codes: G03G 15/0812 characterised by the developer regulating means, e.g. structure of doctor blade
• CPC Class Codes: G03G 15/0817 characterised by the lateral sealing at both sides of the donor member with respect to the developer carrying direction
• CPC Class Codes: G03G 21/1814 Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing G03G21/1835 takes precedence
• CPC Class Codes: G03G 2221/1648 using seals, e.g. to prevent scattering of toner light shields for the photoreceptor G03G2221/1609
• CPC Class Codes: G03G 2221/183 Process cartridge

Abstract

A developing device including a developing roller opposed to a photoconductor and rotatably mounted to a developing case of the developing device. A blade mounting surface is formed in an outer wall of the developing case, that is opposed to the photoconductor, and a blade holder, a blade and a supporting plate, that are laminated with each other, are mounted to the blade mounting surface of the developing case. A part of the blade opposite to a part of the blade sandwiched between the blade holder and the supporting member is elastically bent so as to contact an outer circumferential surface of the developing roller, and seal members are arranged at least along an edge of a longitudinal side of the blade holder at the side of the developing roller and along an edge of another longitudinal side of the blade holder at the opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case.

Claims

1. A developing device, comprising

a developing roller opposed to a photoconductor and rotatably mounted to a developing case of the developing device,

a blade mounting surface formed in an outer wall of the developing case, that is opposed to the photoconductor,

a blade holder, a blade and a supporting member, laminated with each other, and mounted to the blade mounting surface of the developing case,

a first part of the blade located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and elastically bent so as to contact an outer circumferential surface of the developing roller, and

seal members arranged at least along an edge of a longitudinal side of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case.

2. A developing device according to claim 1, wherein the seal members are longer than a longitudinal length of the blade holder, and

the seal members have longitudinal ends that are bent along sides of ends of the blade holder, respectively.

3. A process cartridge, comprising

a developing device mounted to a photoconductor case in which a photoconductor is rotatably supported,

a developing roller opposed to the photoconductor and rotatably mounted to a developing case of the developing device,

a blade mounting surface formed in an outer wall of the developing case, that is opposed to the photoconductor,

a blade holder, a blade and a supporting member laminated with each other and mounted to the blade mounting surface of the developing case,

a first part of the blade located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and elastically bent so as to contact an outer circumferential surface of the developing roller, and

seal members arranged at least along an edge of a longitudinal side of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing rollers respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case.

4. An image forming apparatus, comprising:

a process cartridge, in which

a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported,

a developing roller opposed to the photoconductor is rotatably mounted to a developing case of the developing device,

a blade mounting surface is formed in an outer wall of the developing case, that is opposed to the photoconductor,

a blade holder, a blade and a supporting member, that are laminated with each other, and are mounted to the blade mounting surface of the developing case,

a first part of the blade is located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and is elastically bent so as to contact an outer circumferential surface of the developing roller, and

seal members are arranged at least along an edge of a longitudinal edge of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case;

a transfer device configured to transfer a toner image formed on the photoconductor to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.

5. A developing device, comprising

a developing roller opposed to a photoconductor and rotatably mounted to a developing case of the developing device,

blade mounting surfaces and a recessed surface formed in an outer wall of the developing case, that is opposed to the photoconductor, in vicinity of longitudinal ends and at a center part of the outer wall, respectively, a portion of the recessed surface being recessed from a portion of the blade mounting surfaces,

a blade holder, a blade and a supporting member laminated with each other and mounted to the blade mounting surfaces,

a first part of the blade located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and elastically bent so as to contact an outer circumferential surface of the developing roller,

seal members arranged at least along an edge of a longitudinal side of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case, and

a packing member arranged in a gap between a center part of the blade holder and the recessed surface.

6. A developing device according to claim 5, wherein the seal members are formed with a material that has a density higher than that of toner particles and a rigidity that will not cause any deformation of the blade.

7. A process cartridge, comprising

a developing device mounted to a photoconductor case in which a photoconductor is rotatably supported,

a developing roller opposed to the photoconductor and rotatably mounted to a developing case of the developing device,

blade mounting surfaces and a recessed surface formed in an outer wall of the developing case, that is opposed to the photoconductor, in vicinity of longitudinal ends and at a center part of the outer wall, respectively, a portion of the recessed surface being recessed from a portion of the blade mounting surfaces,

blade holder, a blade and a supporting member laminated with each other and mounted to the blade mounting surfaces,

a first part of the blade located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and elastically bent so as to contact an outer circumferential surface of the developing roller,

seal members arranged at least along an edge of a longitudinal side of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case;

and

a packing member arranged in a gap between a center part of the blade holder and the recessed surface.

8. An image forming apparatus, comprising:

a process cartridge, in which

a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported,

a developing roller opposed to the photoconductor is rotatably mounted a developing case of the developing device, blade mounting surfaces and a recessed surface are formed in an outer wall of the developing case, that is opposed to the photoconductor, in vicinity of longitudinal ends and at a center part of the outer wall, respectively, a portion of the recessed surface being recessed from a portion of the blade mounting surfaces,

a blade holder, a blade and a supporting member, that are laminated with each other, and are mounted to the blade mounting surfaces,

a first part of the blade is located opposite to a second part of the blade, which is sandwiched between the blade holder and the supporting member, and is elastically bent so as to contact an outer circumferential surface of the developing roller,

seal members are arranged at least along an edge of a longitudinal side of the blade holder at a side of the developing roller and along an edge of another longitudinal side of the blade holder at an opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case, and

a packing member is arranged in a gap between a center part of the blade holder and the recessed surface;

a transfer device configured to transfer a toner image formed on the photoconductor to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.

9. A developing device, comprising:

a developing case in which a toner exit opposed to a photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed;

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit;

a blade that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller;

a thin exit seal that is supported by the flat surface of the developing case, a free end side thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller; and

corner seals that seal corners where edges of longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively.

10. A developing device, comprising:

a developing case in which a toner exit opposed to a photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed;

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit;

a blade configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller;

a thin exit seal that is supported by the flat surface of the developing case, a free end side thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller; and

clips that elastically sandwich longitudinal ends of the exit seal and the flat surface of the developing case respectively.

11. A developing device according to claim 10, further comprising:

corner seals that seal corners where longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively.

12. A process cartridge, comprising

a developing device mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including;

a developing case in which a toner exit opposed to the photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

a blade that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

a thin exit seal that is supported by the flat surface of the developing case, a free end side thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller, and

corner seals that seal corners where longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively.

13. A process cartridge, comprising

a developing device mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including;

a developing case in which a toner exit opposed to the photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

a blade configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

a thin exit seal that is supported by the flat surface of the developing case, a free end side thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller, and

clips that elastically sandwich longitudinal ends of the exit seal and the flat surface of the developing cover respectively.

14. A process cartridge according to claim 13, wherein the developing device further includes

corner seals that seal corners where longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively.

15. An image forming apparatus, comprising:

a process cartridge, in which a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including

a developing case in which a toner exit opposed to the photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

a blade that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

a thin exit seal that is supported by the flat surface of the developing case, a free end thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller, and

corner seals that seal corners where longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively;

a transfer device configured to transfer a toner image formed on the photoconductor to a transfer sheet; and

a fixing device configured to fixed the transferred toner image onto the transfer sheet.

16. An image forming apparatus, comprising:

a process cartridge, in which a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including,

a developing case in which a toner exit opposed to the photoconductor and a flat surface extended from a lower edge of the toner exit toward the photoconductor are formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

a blade configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

a thin exit seal that is supported by the flat surface of the developing case, a free end side thereof extended toward the inside of the toner exit elastically contacting the roller part of the developing roller, and

clips that elastically sandwich longitudinal ends of the exit seal and the flat surface of the developing cover, respectively;

a transfer device configured to transfer a toner image formed on the photoconductor to a transfer sheet; and

a fixing device configured to fixed the transferred toner image onto the transfer sheet.

17. An image forming apparatus according to claim 16, wherein the developing device further includes

corner seals that seal corners where longitudinal ends of the exit seal and the supporting walls of the developing case contact each other, respectively.

18. A developing device, comprising:

a developing case in which a toner exit opposed to a photoconductor is formed;

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit;

side seals arranged at longitudinal ends of the toner exit so as to contact outer circumferential surfaces of longitudinal ends of the roller part of the developing roller; and

a blade that is formed with a thin metal plate having elasticity and that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

wherein the blade includes a wide-width part having a length such that longitudinal ends thereof face the side seals respectively and a narrow-width part extended from the wide-width part toward upstream of a rotation direction of the developing roller and configured to have a length that enables the narrow-width part to be bent in a direction orthogonal to a longitudinal direction of the developing roller between the side seals arranged at sides of the toner exit, and a step part forming a boundary between the wide-width part and the narrow-width part is disposed downstream of a contact point of the blade and the roller part of the developing roller in the rotation direction of the developing roller.

19. A developing device according to claim 18, wherein

the length of the narrow-wide part is made longer than an interval between inside surfaces of the side seals such that, when the blade is pressed by the developing roller, the narrow-wide part bends toward a rear side of the toner exit by pressure of the developing roller even after the wide-width part contacts the side seals.

20. A process cartridge, comprising

a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including,

a developing case in which a toner exit opposed to the photoconductor is formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

side seals arranged at longitudinal ends of the toner exit so as to contact outer circumferential surfaces of longitudinal ends of the roller part of the developing roller, and

a blade that is formed with a thin metal plate having elasticity and that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller;

and

wherein the blade includes a wide-width part having a length such that longitudinal ends thereof face the side seals respectively and a narrow-width part extended from the wide-width part toward upstream of a rotation direction of the developing roller and configured to have a length that enables the narrow-width part to be bent in a direction orthogonal to a longitudinal direction of the developing roller between the side seals arranged at sides of the toner exit, and a step part forming a boundary between the wide-width part and the narrow-width part is disposed downstream of a contact point of the blade and the roller part of the developing roller in the rotation direction of the developing roller.

21. An image forming apparatus, comprising:

a process cartridge, in which a developing device is mounted to a photoconductor case in which a photoconductor is rotatably supported, the developing device including,

a developing case in which a toner exit opposed to the photoconductor is formed,

a developing roller including an axial part rotatably supported by supporting walls provided at sides of the developing case and a roller part disposed at the toner exit,

side seals arranged at longitudinal ends of the toner exit so as to contact outer circumferential surfaces of longitudinal ends of the roller part of the developing roller, and

a blade that is formed with a thin metal plate having elasticity and that is configured such that a lower edge thereof contacts the roller part of the developing roller so as to seal a gap between an upper edge of the toner exit and an upper outer circumferential surface of the roller part of the developing roller,

wherein the blade includes a wide-width part having a length such that longitudinal ends thereof face the side seals respectively and a narrow-width part extended from the wide-width part toward upstream of a rotation direction of the developing roller and configured to have a length that enables the narrow-width part to be bent in a direction orthogonal to a longitudinal direction of the developing roller between the side seals arranged at sides of the toner exit, and a step part forming a boundary between the wide-width part and the narrow-width part is disposed downstream of a contact point of the blade and the roller part of the developing roller in the rotation direction of the developing roller;

a transfer device configured to transfer a toner image formed on the photoconductor to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.

22. A developing device, comprising

a toner accommodating part formed in a developing case of the developing device,

a rotating member rotatably housed in the toner accommodating part,

a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case and a flexible stopping claw formed at an end of the rotating axis protruded outside of the wall of the developing case and inserted into an insertion hole formed in a gear and stopped by being engaged with the gear, and

a seal stuck to an outside surface of the gear so as to seal the insertion hole.

23. A developing device, comprising

a toner accommodating part formed in a developing case of the developing device,

a rotating member rotatably housed in the toner accommodating part,

a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case,

an end of the rotating axis protruded outside of the wall of the developing case and engaged with a gear,

an engaging hole formed in the wall of the developing case,

a bearing fit into the engaging hole, and

a bearing seal formed with foaming polyurethane in a donut shape so as to pass through the rotating axis and fixed to an end of the bearing facing the toner accommodating part,

wherein an outer radius of the bearing seal is larger than an inner radius of the engaging hole by about 0.2-1.0 mm.

24. A developing device according to claim 23, wherein a D-shaped part is formed at a part of the rotating axis engaging with the gear and a chamfer is formed between a part of the rotating member where the D-shaped part is formed and a part of the rotating member where the D-shaped part is not formed.

25. A process cartridge, comprising

a photoconductor unit, in which a photoconductor is rotatably accommodated, and a developing device are integrated in a body,

wherein the developing device includes a toner accommodating part formed in a developing case of the developing device, a rotating member rotatably housed in the toner accommodating part, a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case and a flexible stopping claw formed at an end of the rotating axis protruded outside of the wall of the developing case and inserted into an insertion hole formed in a gear and stopped by being engaged with the gear, and a seal stuck to an outside surface of the gear so as to seal the insertion hole.

26. A process cartridge, comprising

a photoconductor unit, in which a photoconductor is rotatably accommodated, and a developing device are integrated in a body,

wherein the developing device includes a toner accommodating part formed in a developing case of the developing device, a rotating member rotatably housed in the toner accommodating part, a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case, an end of the rotating axis protruded outside of the wall of the developing case and engaged with a gear, an engaging hole formed in the wall of the developing case, a bearing fit into the engaging hole, a bearing seal formed with foaming polyurethane in a donut shape so as to pass through the rotating axis and fixed to an end of the bearing facing the toner accommodating part, and an outer radius of the bearing seal that is larger than an inner radius of the engaging hole by about 0.2-1.0 mm.

27. An image forming apparatus, comprising:

a process cartridge having a photoconductor unit in which a photoconductor is rotatably accommodated and a developing device are integrated in a body, and having, in the developing device, a toner accommodating part formed in a developing case of the developing device, a rotating member rotatably housed in the toner accommodating part, a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case and a flexible stopping claw formed at an end of the rotating axis protruded outside of the wall of the developing case is inserted into an insertion hole formed in a gear and is stopped by being engaged with the gear, and a seal stuck to an outside surface of the gear so as to seal the insertion hole;

a latent image forming device to form an electrostatic latent image on an outer circumferential surface of the photoconductor by exposing the outer circumferential surface of the photoconductor to light;

a transfer device configured to transfer the latent image on the photoconductor, which has been developed with toner supplied from the developing device, to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.

28. An image forming apparatus, comprising:

a process cartridge, having a photoconductor unit in which a photoconductor is rotatably accommodated and a developing device are integrated in a body, and having, in the developing device, a toner accommodating part formed in a developing case of the developing device, a rotating member rotatably housed in the toner accommodating part, a rotating axis of the rotating member passing through a wall of the developing case to protrude outside of the wall of the developing case, an end of the rotating axis protruded outside of the wall of the developing case and engaged with a gear, an engaging hole formed in the wall of the developing case, a bearing fit into the engaging hole, a bearing seal formed with foaming polyurethane in a donut shape so as to pass through the rotating axis and fixed to an end of the bearing facing the toner accommodating part, and an outer diameter of the bearing seal that is larger than an inner diameter of the engaging hole by about 0.2-1.0 mm in the radius;

a latent image forming device to form an electrostatic latent image on an outer circumferential surface of the photoconductor by exposing the outer circumferential surface of the photoconductor to light;

a transfer device configured to transfer the latent image on the photoconductor, which has been developed with toner supplied from the developing device, to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.

29. A photoconductor unit, in which a photoconductor is rotatably supported and a used toner collecting unit configured to collect residual used toner on the photoconductor is formed, the photoconductor unit comprising:

a narrow and long collecting inlet formed in the used toner collecting unit at a position adjacent to an outer circumferential surface of the photoconductor, the collecting inlet extending along substantially an entire length of the photoconductor;

side seals disposed at longitudinal ends of the collecting inlet so as to slidably contact an outer circumferential surface of ends of the photoconductor;

a long blade provided at one longitudinal edge of the collecting inlet so as to scrape off residual used toner on an outer circumferential surface of the photoconductor; and

a long inlet seal stuck to another longitudinal edge of the collecting inlet so as to slidably contact the outer circumferential surface of the photoconductor;

wherein support parts are formed at longitudinal ends of the inlet seal protruding in a direction orthogonal to a longitudinal direction of the inlet seal to increase a sticking area of the inlet seal to the another longitudinal edge of the collecting inlet.

30. A photoconductor unit according to claim 29, wherein longitudinal ends of the inlet seal are overlaid with the side seals with respective outer edges of the inlet seal and the side seals aligned with each other, and pressing seals that are formed in a substantially L-shape with a fixing part and a leakage preventing part are disposed such that the fixing part of the pressing seals is stuck on end parts of the inlet seal and the leakage preventing part is stuck at a position to contact outer end surfaces of the side seals and the inlet seal.

31. A process cartridge, comprising

a developing device, in which a developing roller is rotatably supported, and a photoconductor unit are integrated in a body,

wherein the photoconductor unit includes a photoconductor rotatably supported and a used toner collecting unit to collect residual used toner on the photoconductor is formed, the photoconductor unit including,

a narrow and long collecting inlet formed in the used toner collecting unit at a position adjacent to an outer circumferential surface of the photoconductor extending along substantially an entire length of the photoconductor,

side seals disposed at longitudinal ends of the collecting inlet so as to slidably contact an outer circumferential surface of ends of the photoconductor,

a long blade provided at one longitudinal edge of the collecting inlet so as to scrape off residual used toner on an outer circumferential surface of the photoconductor, and

a long inlet seal stuck to another longitudinal edge of the collecting inlet so as to slidably contact the outer circumferential surface of the photoconductor, and

wherein support parts are formed at longitudinal ends of the inlet seal protruding in a direction orthogonal to a longitudinal direction of the inlet seal to increase a sticking area of the inlet seal to the another longitudinal edge of the collecting inlet.

32. An image forming apparatus, comprising:

a process cartridge having a developing device, in which a developing roller is rotatably supported, and a photoconductor unit integrated in a body, and the photoconductor unit having a photoconductor rotatably supported therein and a used toner collecting unit to collect residual used toner on the photoconductor, the photoconductor unit including,

a narrow and long collecting inlet formed in the used toner collecting unit at a position adjacent to an outer circumferential surface of the photoconductor extending along substantially an entire length of the photoconductor,

side seals disposed at longitudinal ends of the collecting inlet so as to slidably contact an outer circumferential surface of ends of the photoconductor,

a long blade provided at one longitudinal edge of the collecting inlet so as to scrape off residual used toner on an outer circumferential surface of the photoconductor, and

a long inlet seal stuck to another longitudinal edge of the collecting inlet so as to slidably contact the outer circumferential surface of the photoconductor, and

wherein support parts are formed at longitudinal ends of the inlet seal protruding in a direction orthogonal to a longitudinal direction of the inlet seal to increase a sticking area of the inlet seal to the another longitudinal edge of the collecting inlet;

a latent image forming device configured to form an electrostatic latent image on the outer circumferential surface of the photoconductor by exposing the outer circumferential surface of the photoconductor to light;

a transfer device configured to transfer the latent image on the photoconductor, which has been developed with toner supplied from the developing device, to a transfer sheet; and

a fixing device configured to fix the transferred toner image onto the transfer sheet.