Developing cartridge, process unit, and image forming apparatus

Abstract

A developing cartridge removably set in a laser printer includes a drive gear that inputs a drive force thereto, a detection gear that irreversibly moves from a unused position where the detection gear does not engage with the drive gear, to a used position where the detection gear does not engage with the drive gear, through a drive force transmitting position where the detection gear engages with the drive gear, and a contact member formed on the detection gear. Provided in a main frame of the laser printer is an actuator that moves the detection gear from the unused position to the drive force transmitting position as the contact member contacts the actuator when the developing cartridge is set in the main frame of the laser printer.

1. A developing cartridge, comprising:
 a developing agent containing chamber that contains a developing agent; 
 a drive gear configured to receive a drive force; and 
 a detection gear irreversibly movable from an unused position where the detection gear does not communicate with the drive gear, to a used position where the detection gear does not communicate with the drive gear, through a drive force transmitting position where the detection gear communicates with the drive gear. 
 
     
     
       2. The developing cartridge according to  claim 1 , wherein the detection gear is placed in the unused position when the developing cartridge is unused, the detection gear moves from the unused position to the drive force transmitting position, in association with a setting operation of the developing cartridge in an image forming apparatus, and the detection gear moves to the used position after the drive force is transmitted from the drive gear to the detection gear. 
     
     
       3. The developing cartridge according to  claim 2 , wherein the detection gear includes a contact member, and when the developing cartridge is set in the image forming apparatus, the contact member contacts a contacted member provided in the image forming apparatus so the detection gear is moved from the unused position to the drive force transmitting position. 
     
     
       4. The developing cartridge according to  claim 3 , further comprising:
 an agitating member configured to agitate the developing agent in the developing agent containing chamber; and 
 an agitating member shaft configured to rotate the agitating member, wherein the detection gear rotates in accordance with the rotation of the agitating member shaft. 
 
     
     
       5. The developing cartridge according to  claim 3 , further comprising a cover member that supports the detection gear. 
     
     
       6. The developing cartridge according to  claim 5 , wherein the cover member includes an opening that exposes the contact member and is shaped along a movement path of the contact member. 
     
     
       7. The developing cartridge according to  claim 6 , wherein the opening is formed such that one end of the opening is associated with a position of the contact member when the detection gear is in the unused position, and the other end of the opening is associated with a position of the contact member when the detection gear is in the used position. 
     
     
       8. The developing cartridge according to  claim 7 , wherein the contact member is exposed from the opening at the one end of the opening up to a predetermined height and an extended portion is formed at the other end of the opening to a height substantially equal to the predetermined height. 
     
     
       9. The developing cartridge according to  claim 7 , wherein the cover further includes a resistance application portion, that applies resistance to the contact member when the contact member moves, disposed between the one end and the other end of the opening. 
     
     
       10. The developing cartridge according to  claim 1 , further comprising an intermediate gear that communicates with the drive gear, wherein the detection gear does not engage with the intermediate gear when the detection gear is in the unused position, and the detection gear engages with the intermediate gear when the detection gear is in the drive force transmitting position. 
     
     
       11. The developing cartridge according to  claim 10 , wherein the detection gear is a partly teeth missing gear having a tooth portion that engages with the intermediate gear only when the detection gear is in the drive force transmitting position. 
     
     
       12. A process unit, comprising:
 a developing cartridge including a developing agent containing chamber that contains a developing agent; and 
 a photosensitive member frame that supports a photosensitive member and is formed with a process accommodating portion that accommodates the developing cartridge, and wherein the developing cartridge includes: 
 a drive gear that inputs a drive force thereto; and 
 a detection gear that is formed with a determination member that irreversibly moves from an unused position where the detection gear does not communicate with the drive gear, to a used position where the detection gear does not communiate communicate with the drive gear, through a drive force transmitting position where the detection gear communicates with the drive gear, wherein the photosensitive member frame includes a receiving portion that is formed in association with a movement path of the determination member and receives the determination member. 
 
     
     
       13. The process unit according to  claim 12 , wherein the developing cartridge includes an agitating member that agitates the developing agent in the developing agent containing chamber and a shaft that rotates the agitating member, and wherein the detection gear rotates together with the shaft. 
     
     
       14. The process unit according to  claim 12 , wherein the developing cartridge includes a cover member that supports the detection gear. 
     
     
       15. The process unit according to  claim 14 , wherein the cover member includes an opening that exposes the determination member and is shaped along a movement path of the determination member. 
     
     
       16. The process unit according to  claim 15 , wherein the opening is formed such that one end of the opening is associated with a position of the determination member when the detection gear is in the unused position, and the other end of the opening is associated with a position of the determination member when the detection gear is in the used position. 
     
     
       17. The process unit according to  claim 16 , wherein the determination member is exposed from the opening at the one end of the opening up to a predetermined height and an extended portion is formed at the other end of the opening to a height substantially equal to the predetermined height. 
     
     
       18. The process unit according to  claim 17 , wherein the receiving portion is formed to receive the extended portion formed at the opening. 
     
     
       19. The process unit according to  claim 12 , wherein the developing cartridge further includes an intermediate gear that communicates with the drive gear, wherein the detection gear does not engage with the intermediate gear when the detection gear is in the unused position, and the detection gear engages with the intermediate gear when the detection gear is in the drive three transmitting position. 
     
     
       20. An image forming apparatus, comprising: wherein the detection gear does not engage with the intermediate gear when the detection
 a main accommodating portion that removably accommodates therein a gear is in the unused position, and the detection gear engages with the intermediate gear when process unit including a developing cartridge and a photosensitive member frame formed the detection gear is in the drive force transmitting position. with a process accommodating portion that accommodates the developing cartridge, the photosensitive member frame supporting a photosensitive member; 
 wherein the developing cartridge includes:
 a developing agent containing chamber that contains a developing agent; 
 a drive gear that inputs a drive force thereto; and 
 a detection gear that is formed with a determination member that irreversibly moves from an unused position where the detection gear does not communicate with the drive gear, to a used position where the detection gear does not communicate with the drive gear, through a drive force transmitting position where the detection gear communicates with the drive gear; and wherein the image forming apparatus further comprises: 
 
 a contacted member, provided at the main accommodating portion, that contacts the determination member and moves the detection gear from the unused position to the drive force transmitting position when the process unit is accommodated in the main accommodating portion. 
 
     
     
       21. The image forming apparatus according to  claim 20 , wherein when the determination member contacts the contacted member, the determination member moves to a direction opposite to a setting direction of the process unit in the image forming apparatus. 
     
     
       22. The image forming apparatus according to  claim 20 , wherein the detection gear is placed in the unused position when the developing cartridge is unused, the detection gear moves from the unused position to the drive force transmitting position, in association with a setting operation of the process unit in the image forming apparatus, and the detection gear moves to the used position after the drive force is transmitted from the drive gear to the detection gear. 
     
     
       23. The image forming apparatus according to  claim 20 , wherein the contacted member is movable between a first position and a second position, and the image forming apparatus further includes a sensor that determines whether the contacted member is in the first position or the second position, and an urging member that urges the contacted member to place the contacted member in the first position. 
     
     
       24. The image forming apparatus according to  claim 23 , wherein the contacted member is in the second position against an urging force of the urging member when the detection gear is in the unused position, and the contacted member is placed in the first position in accordance with the urging force of the urging member when the detection gear is moved to the used position. 
     
     
       25. The image forming apparatus according to  claim 20 , wherein the developing cartridge further includes an intermediate gear that communicates with the drive gear, wherein the detection gear does not engage with the intermediate gear when the detection gear is in the unused position, and the detection gear engages with the intermediate gear when the detection gear is in the driving transmitting position. 
     
     
       26. The developing cartridge according to claim 1, further comprising:
 a shaft configured to rotate during operation of the developing cartridge, wherein the detection gear rotates in accordance with the rotation of the shaft.