1. An image forming apparatus comprising:
an image bearing member having a layer including a lubricant on a surface, which carries an electrostatic latent image;
a developing device configured to develop an electrostatic latent image on the image bearing member as a developer image;
a cleaning device that presses a cleaning blade on the image bearing member and removes a developer on the image bearing member when the image bearing member rotates;
a detecting unit configured to detect information about an operation time which is a rotation time of the image bearing member from when the image bearing member has never been used prior; and
a control unit,
wherein the image bearing member is rotated in a first direction to form an image,
wherein the control unit performs, when the image is formed, a first stop operation control in which the image bearing member is stopped without rotating the image bearing member in a second direction which is in an opposite direction of the first direction, and a second stop operation control in which the image bearing member is stopped by rotating in the second direction after being stopped by rotating in the first direction without rotating in the second direction, and
wherein the control unit performs, when an operation time of the image bearing member acquired from information about the operation time detected by the detection unit is defined as a first operation time and an operation time of the image bearing member which is longer than the first operation time is defined as a second operation time, the first stop operation control in a case of the first operation time, and the second stop operation control in a case of the second operation time.
2. The image forming apparatus according to claim 1, wherein the information about the operation time is number of rotations or a rotation time of the image bearing member, and the first stop operation is selected when the number of rotations or the rotation time is less than or equal to a threshold value, and the second stop operation is selected when the number of rotations speed or the rotation time is greater than or equal to a threshold value.
3. The image forming apparatus according to claim 1, further comprising an environment detection unit configured to detect a temperature in an image forming apparatus,
wherein the information about the operation time of the image bearing member is corrected according to a detection result of the environment detection unit.
4. The image forming apparatus according to claim 1, further comprising an environment detection unit configured to detect temperature in which an image forming apparatus is disposed,
wherein a threshold value for selecting a stop operation of the image bearing member is corrected according to a detection result of the environment detection unit.
5. An image forming apparatus comprising:
an image bearing member that carries an electrostatic latent image;
a developing apparatus configured to develop an electrostatic latent image on the image bearing member as a developer image;
a cleaning apparatus that presses a cleaning blade including a lubricant on a surface onto the image bearing member and removes a developer on the image bearing member when the image bearing member rotates;
a detecting unit configured to detect information about an operation time of the cleaning blade from when the cleaning blade has never been used prior; and
a control unit,
wherein the image bearing member is rotated in a first direction to form an image,
wherein the control unit performs, when the image is formed, a first stop operation control in which the image bearing member is stopped without rotating the image bearing member in a second direction which is in an opposite direction of the first direction, and a second stop operation control in which the image bearing member is stopped by rotating in the second direction after being stopped by rotating in the first direction without rotating in the second direction, and
wherein the control unit performs, when an operation time of the cleaning blade acquired from information about the operation time detected by the detection unit is defined as a first operation time and an operation time of the cleaning blade is longer than the first operation time is defined as a second operation time, the first stop operation control in a case of the first operation time, and the second stop operation control in a case of the second operation time.
6. The image forming apparatus according to claim 5, wherein the information about the operation time is number of rotations or a rotation time of the image bearing member, and the first stop operation is selected when the number of rotations or the rotation time is less than or equal to a threshold value, and the second stop operation is selected when the number of rotations or the rotation time is greater than or equal to a threshold value.
7. The image forming apparatus according to claim 5, further comprising a temperature detection unit configured to detect a temperature in an image forming apparatus,
wherein the information about the operation time of the image bearing member is corrected according to a detection result of the environment detection unit.
8. The image forming apparatus according to claim 5, further comprising an environment detection unit configured to detect temperature in which an image forming apparatus is disposed,
wherein a threshold value for selecting a stop operation of the image bearing member is corrected according to a detection result of the environment detection unit.
9. The image forming apparatus according to claim 1, wherein the cleaning blade is disposed in a counter direction with respect to the first direction.
10. The image forming apparatus according to claim 5, wherein the cleaning blade is disposed in a counter direction with respect to the first direction.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A master cylinder comprising
a stepped cylinder having a large diameter cylinder portion and a small diameter cylinder portion;
a stepped piston having a large diameter piston portion slidably inserted into the large diameter cylinder portion of the stepped cylinder and a small diameter piston portion slidably inserted into the small diameter cylinder portion; and
a reverse flow checking opening and closing portion for partitioning the inside of the stepped cylinder into a large diameter pressurizing chamber on the large diameter piston portion side and a small diameter hydraulic chamber on the small diameter piston portion side and permitting a brake fluid to flow only from the large diameter pressurizing chamber side to the small diameter hydraulic chamber side, the reverse flow checking opening and closing portion being opened by reducing a volume of the large diameter pressurizing chamber by sliding movement of the stepped piston toward the small diameter hydraulic chamber side to thereby supply the brake fluid from the large diameter pressurizing chamber side to the small diameter hydraulic chamber side; and
a control valve for gradually reducing a hydraulic pressure of the large diameter pressurizing chamber in accordance with the rise of the hydraulic pressure of the small diameter hydraulic chamber.
2. The master cylinder according to claim 1, wherein the control valve includes a valve piston and a valve spring for urging the valve piston within a valve cylinder; and the valve piston reduces the hydraulic pressure of the large diameter pressurizing chamber when a total force of a propulsive force produced by the hydraulic pressure of the small diameter hydraulic chamber and a propulsive force produced by the hydraulic pressure of the large diameter pressurizing chamber exceeds an urging force by the valve spring.
3. The master cylinder according to claim 2, wherein the master cylinder includes a reservoir for storing the brake fluid; the control valve is provided with at least two ring seals between the valve cylinder and the valve piston to partition the inside of the valve cylinder, and a chamber formed between the ring seals and the small diameter hydraulic chamber communicate with each other; and the valve spring is provided at one side of the valve piston, and a relief chamber for communicating to the reservoir and the large diameter pressurizing chamber is provided at the other side of the valve piston, with an opening and closing valve mechanism for communicating and cutting between the relief chamber and the large diameter pressurizing chamber being provided.
4. The master cylinder according to claim 3, wherein the at least two ring seals are provided at the valve piston, and the diameter of the ring seal provided on the valve spring side is larger than that of the ring seal provided on the relief chamber side.
5. The master cylinder according to claim 3, wherein the valve cylinder is partitioned into three chambers, the relief chamber, the chamber formed between the ring seals and a damper chamber which stores the valve spring, by the two ring seals, and the valve piston is formed with a throttle path one end of which is opened to the relief chamber and the other end of which is opened to the damper chamber.
6. The master cylinder according to claim 1, further comprising
a reservoir for storing the brake fluid;
a cut-off portion on the large diameter pressurizing chamber side for cutting communication between the large diameter pressurizing chamber and the reservoir by being closed by the sliding movement of the stepped piston to the small diameter hydraulic chamber side; and
a cut-off portion on the small diameter hydraulic chamber side for cutting communication between the large diameter pressurizing chamber and the small diameter hydraulic chamber by being closed by the sliding movement of the stepped piston to the small diameter hydraulic chamber side, wherein
an ineffective stroke of the stepped piston until the cut-off portion on the small diameter hydraulic chamber side is brought into a closed state is made longer than an ineffective stroke of the stepped piston until the cut-off portion on the large diameter pressurizing chamber side is brought into a closed state.
7. The master cylinder according to claim 6, wherein the control valve includes a valve piston and a valve spring for urging the valve piston within a valve cylinder; and the valve piston reduces the hydraulic pressure of the large diameter pressurizing chamber when a total force of a propulsive force produced by the hydraulic pressure of the small diameter hydraulic chamber and a propulsive force produced by the hydraulic pressure of the large diameter pressurizing chamber exceeds an urging force by the valve spring.
8. The master cylinder according to claim 7, wherein the control valve is provided with at least two ring seals between the valve cylinder and the valve piston to partition the inside of the valve cylinder, and a chamber formed between the ring seals and the small diameter hydraulic chamber communicate with each other; and the valve spring is provided at one side of the valve piston, and a relief chamber for communicating to the reservoir and the large diameter pressurizing chamber is provided at the other side of the valve piston with an opening and closing valve mechanism for communicating and cutting between the relief chamber and the large diameter pressurizing chamber being provided.
9. The master cylinder according to claim 8, wherein the valve cylinder is partitioned into three chambers, the relief chamber, the chamber formed between the ring seals and a damper chamber which stores the valve spring, by the two ring seals, and the valve piston is formed with a throttle path one end of which is opened to the relief chamber and the other end of which is opened to the damper chamber.
10. A master cylinder comprising
a reservoir for storing a brake fluid;
a stepped cylinder having a large diameter cylinder portion and a small diameter cylinder portion;
a stepped piston having a large diameter piston portion slidably inserted into the large diameter cylinder portion of the stepped cylinder and a small diameter piston portion slidably inserted into the small cylinder portion;
a reverse flow checking opening and closing portion for partitioning the inside of the stepped cylinder into a large diameter pressurizing chamber on the large diameter piston portion side and a small diameter hydraulic chamber on the small diameter piston portion side and permitting a brake fluid to flow only from the large diameter pressurizing chamber side to the small diameter hydraulic chamber side;
a cut-off portion on the large diameter pressurizing chamber side for cutting communication between the large diameter pressurizing chamber and the reservoir by being closed by sliding movement of the stepped piston to the small diameter hydraulic chamber; and
a cut-off portion on the small diameter hydraulic chamber side for cutting communication between the large diameter pressurizing chamber and the small diameter hydraulic chamber by being closed by the sliding movement of the stepped piston to the small diameter hydraulic chamber side, the brake fluid being supplied from the large diameter pressurizing chamber side to the small diameter hydraulic chamber side by the opening operation of the reverse flow checking opening and closing portion by reducing a volume of the large diameter pressurizing chamber by the sliding movement of the stepped piston to the small diameter hydraulic chamber side, wherein
an ineffective stroke of the stepped piston until the cut-off portion on the small diameter hydraulic chamber side is brought into the closed state is made longer than an ineffective stroke of the stepped piston until the cut-off portion on the large diameter pressurizing chamber side is brought into a closed state.