Patent Application
20080089701
These and other aspects and advantages of the invention will be apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
Referring to
An exposing unit 40 scans the light corresponding to image information to the photosensitive drum 10 charged to have the uniform electric potential to form an electrostatic latent image. As shown, the exposing unit 40 comprises a laser scanning unit (LSU) that uses a laser diode as a light source is commonly used as the exposing unit 40. However, it is understood that the light can be provided by other devices.
To develop the electrostatic latent image formed in the photosensitive drum 10, the main bodies 20 receive toner from the toner containers 30. As shown, the toner containers 30 include a yellow toner container 30Y accommodating yellow (Y) toner, a magenta toner container 30M accommodating magenta (M) toner, a cyan toner container 30C accommodating yellow (Y) toner, and a black toner container 30K accommodating black (K) toner. The developing device main bodies 20 include a yellow main body 20Y to receive the yellow toner from the yellow toner container 30Y, a magenta main body 20M to receive the magenta toner from the magenta toner container 30M, a cyan main body 20C to receive the cyan toner from the cyan toner container 30C, and the black main body 20K to receive the black toner from the black toner container 30K. As shown in
The developing device main bodies 20 each include developing rollers 21 separated from the photosensitive drum 10 by a developing gap. While not required in all aspects, the developing gap is preferably about several tens to several hundreds of microns.
In the shown image forming apparatus, the main bodies 20Y, 20M, 20C, and 20K sequentially operate to form an image, which is referred to as a multi-pass method. By way of example of the multi-pass method, where the color black is to be applied, a developing bias is applied to the developing roller 21K of a selected developing device main body 20K and developing biases are not applied to the developing rollers 21Y, 21M, and 21C of the remaining developing device main bodies 20Y, 20M, and 20C. Alternatively, development preventing biases that prevent the toner image from being developed may be applied to the developing rollers 21Y, 21M, and 21C of the remaining developing device main bodies 20Y, 20M, and 20C. Also, only the developing roller 21K of the selected developing device main body 20K may rotate and the developing rollers 21Y, 21M, and 21C of the remaining developing device main bodies 20Y, 20M, and 20C may not rotate. If another color (e.g., cyan) is being applied after the color black, the developing bias is applied to the main body 20C and/or the developing roller 21C is allowed to rotate, and the remaining developing device main bodies 20Y, 20M, and 20K are not biased toward the developing rollers 21Y, 21M, and 21K and/or the developing rollers 21Y, 21M, and 21K are not allowed to rotate. The process is repeated for each color or color combination being applied.
The plurality of developing device main bodies 20Y, 20M, 20C, and 20K, as illustrated in
The developing roller 21 develops the electrostatic latent image formed in the photosensitive drum 10 using the toner. A restricting blade 27 restricts the thickness of the toner attached to the outer circumference of the developing roller 21 and is on the developing roller 21. The supplying roller 22 rotates while contacting the developing roller 21 to attach the toner (non-magnetic toner) to the developing roller 21 by a friction charge.
The plurality of augers 23 and 24 supply the toner supplied through the toner supplier 25 to the developing roller 21 and have a plurality of impellers. While not required in all aspects, the transmission directions of the plurality of augers 23 and 24 are preferably opposite to each other.
The toner supplier 25 is extended rearward from the accommodating unit 29. A supplying hole 28 is on the toner supplier and receives the toner from the toner container 30 into the toner supplying unit 25. A toner discharging hole 31 which connects to the supplying hole 28 is provided in the toner container 30. The toner container 30 includes a shutter 33 that opens and closes the toner discharging unit 31. Therefore, the shutter 33 opens the toner discharging hole 31 when the toner container 30 is mounted in the developing device main body 20, and closes the toner discharging hole 31 when the toner container 30 is separated from the developing device main body 20.
A supplier 39 supplies the toner stored in the toner container 30 to the toner discharging hole 31. The supplier 39 is connected to a gear 32 provided in one side of the toner container 30. Therefore, when the gear 32 receives power to rotate, the supplier 39 also rotates to transmit the toner stored in the toner container 30 to the toner discharging hole 31.
A solenoid 40 restricts the turning on or off of the gear 32 of the toner container 30. Since the solenoid 40 turns off or on the driving of the gear 35 while contacting or non-contacting a stopper 36 provided in the connection gear 34, the driving of the gear 32 of the toner container 30 is also controlled by turning on or off the solenoid 40.
The intermediate transferring belt 51 is supported by supporting rollers 52 and 53 to travel at the same traveling linear velocity as the rotating linear velocity of the photosensitive drum 10. The length of the intermediate transferring belt 51 is generally equal to or larger than the length of the paper P of the maximum size that is used for the image forming apparatus.
The first transferring roller 54 faces the photosensitive drum 10. A first transferring bias is applied to the first transferring roller 54 to transfer the toner image developed in the photosensitive drum 10 to the intermediate belt 51. A second transferring roller 60 faces the intermediate transferring belt 51. The second transferring roller 60 is separated from the intermediate transferring belt 51 while the toner image is transferred from the photosensitive drum 10 to the intermediate transferring belt 51. The second transferring roller 60 contacts the intermediate transferring belt 51 by predetermined pressure when the toner image is completely transferred to the intermediate transferring belt 51. A second transferring bias that transfers the toner image to the paper P is applied to the second transferring roller 60 to bias against the supporting roller 53. The fixing device 70 applies heat and pressure to the toner image transferred to the paper to fix the toner image to the paper.
The gear 32 of the toner container 30 is geared with the gear 35 of the connection gear 34 to rotate when the connection gear 34 rotates. When the solenoid 40 is turned off, the solenoid 40 contacts the stopper 36 so that the gear 32 of the toner container 30 is not driven. At this time, since the supplier 39 does not supply the toner to the toner discharging hole 31, the toner is not supplied to the developing device main body 20. When the solenoid 40 is turned on, the solenoid 40 is separated from the stopper 36 so that the gear 32 of the toner container 30 is driven. At this time, the supplier 39 supplies the toner to the toner discharging hole 31.
When the rotating speed ratio of the gear 32 of the toner container 30 is uniform and the time when the solenoid 40 is turned on is uniform, the gear 32 of the toner container 30 rotates for the time when the solenoid 40 is turned on so that the amount of the supplied toner is uniform. That is, the uniform amount of toner is supplied to the developing device main body 20 for the time when the solenoid 40 is turned on. Therefore, since the amount of toner applied is generally equal for each time the solenoid 40 is turned on, it is possible to estimate the total amount of the supplied toner when the total number of times at which the solenoid 40 is turned on is measured.
The number of times at which the solenoid 40 is turned on can be calculated using a recording medium (counting memory) described later. Therefore, it is possible to measure the total number of times at which the solenoid 40 is turned on.
The toner sensor 42 that measures the amount of the toner accommodated in the developing device main body 20 is provided in the developing device main body 20. According to an aspect of the invention, the toner sensor 42 includes a light emitting unit and a light receiving unit so that the light emitted from the light emitting unit is received by the light receiving unit and that output is made to correspond to the amount of the toner in accordance with the amount of the light received by the light receiving unit.
As illustrated in
The solenoid driving unit 102 turns on or off the solenoid 40 in accordance with the toner supply control signal of the printer controller 100. As the solenoid 40 is turned on or off, it is possible to control the supply of the toner to the developing device main body 20.
A toner container toner amount detector 103 that measures the total number of times at which the solenoid 40 is turned on to calculate the amount of the toner left in the corresponding toner container 30Y, 30M, 30C, 30K is connected to the printer controller 100. The toner container toner amount detector 103 includes a driving signal detector 103-1 that receives one end of the toner supply control signal output from the printer controller 100 to detect the driving signal (on) of the solenoid driving unit 102 and to output a detection signal in accordance with the detection result. A counting memory 103-2 calculates the total number of times at which the solenoid 40 is turned on based on the detection signal of the driving signal detector 103-1 and stores the total number of times. However, it is understood that other mechanisms can be used to estimate an amount of toner that has been used, such as a number of pages which have been printed, a number of rotations that the gear 32 is turned, or other like measurement techniques.
The printer controller 100 requests to detect from the counting memory 103-2 to receive information on the total number of times at which the solenoid 40 is turned on. The printer controller 100 can recognize the amount of the toner left in the corresponding toner container 30Y, 30M, 30C, 30K using the total number of times found by detecting the counting memory 103-2. Therefore, a storage unit 106 includes a table T that previously writes down information on the amount of the toner of the corresponding toner container 30Y, 30M, 30C, 30K corresponding to the total number of times at which the solenoid 40 is turned on. The table T can be calculated from experimental results.
When it is determined that the toner amount CT found by detecting the counting memory 103-2 is not larger than a reference toner amount LT (that is, the amount of the toner left in the corresponding toner container 30Y, 30M, 30C, 30K is less than a proper amount), the printer controller 100 applies a toner supply signal for turning on the solenoid 40 to the solenoid driving unit 102. A developing device toner amount detector 104 detects the amount of the toner left in the corresponding developing device main body 20Y, 20M, 20C, 20K and is connected to the printer controller 100. In
The developing device toner amount detector 104 includes the toner sensor 42 and a converter 43 that converts the output of the toner sensor 42 into digital data. The resolving power of the toner sensor 42 is determined by the number of bits assigned to the digital data. According to the shown embodiment, the resolving power is 8 bits. However, the present invention is not limited to the 8 bit resolving power.
The printer controller 100 determines the amount of the toner left in the corresponding developing device main body 20Y, 20M, 20C, 20K based on the digital data provided from the converter 43 of the developing device toner amount detector 104 and can know whether an adequate amount of toner is left in the developing device main body 20Y, 20M, 20C, 20K based on the digital data. Information on the toner amount obtained by the toner sensor 42 is not always reliable. As illustrated in
Referring to
The error code E2 represents that the sensor value is no less than 250. In this case, a small amount of light is received by the light receiving unit of the sensor 42 due to the defect of the light emitting unit of the toner sensor 42, in which the amount of the toner may be different from the amount of the toner of the developing device main body 20.
The error code E3 represents that the sensor value is fixed to a uniform value. In this case, the light emitted by the light emitting unit is not normally received due to the defect of the light receiving unit of the toner sensor 42. The sensor value is fixed based upon the specific type of sensors used (such as the type of emitting/receiving units), and is experimentally determined to occur at a predetermined high level.
The error code E4 represents that the sensor value is not more than a uniform value (Te). An example of Te is 30, but is not restricted there to. In this case, the toner of the developing device main body 20 is exhausted so that it is necessary to supply a toner to the developing device main body 20.
The error code E5 represents that the sensor value is no more than 15. In this case, the agitation of the toner in the developing device main body 20 is not properly performed so that the toner is inclined to deviate from the sensing region of the sensor 42.
As described above, when the corresponding error factors are determined based on the sensor value output from the toner sensor 42, it is preferable that information on the amount of the toner is obtained many times through the toner sensor 42 while printing is performed on a recording medium, the obtained information items are averaged, and the error factor is determined based on the sensor value.
When the error factor is determined in accordance with the sensor value provided by the developing device toner amount detector 104, the printer controller 100 displays an error factor on the display unit 105 and displays a guide message for taking the corresponding measures.
A method of recognizing error according to an aspect of the present invention described above will be described with reference to the
The detected toner amount MT and the reference toner amount RT set in order to determine whether a proper amount of toner is left are compared with each other (operation 203). When it is determined that the detected toner amount MT is larger than the reference toner amount RT, that is, the proper amount of toner is left in the corresponding developing device main body 20Y, 20M, 20C, 20K, the solenoid 40 is turned off (operation 204). When it is determined that the toner amount MT is not larger than the reference toner amount RT (that is, the proper amount of toner is not left in the corresponding developing device main body 20Y, 20M, 20C, 20K), the printer controller 100 applies the toner supply signal to the solenoid driving unit 102 so that the solenoid 40 is turned on for a uniform time 205 and the toner in the corresponding toner container 30Y, 30M, 30C, 30K is supplied to the corresponding developing device main body 20Y, 20M, 20C, 20K. At this time, the driving signal detector 103-1 of the toner container toner amount detector 103 receives the toner supply signal to detect the driving number of times and the counting memory 103-2 calculates and stores the total number of times the solenoid 40 is turned on. However, it is understood that operation 205 need not be performed in all aspects of the invention.
The printer controller 100 estimates the amount of the toner supplied to the corresponding developing device main body 20Y, 20M, 20C, 20K in accordance with the total driving number of times of the solenoid 40 stored in the counting memory 103-2 and calculates the amount of the toner left in the toner container 30 based on the amount of the toner supplied to the corresponding developing device main body 20Y, 20M, 20C, 20K to produce a calculated amount CT (operation 209).
In operation 211, the printer controller 100 compares the calculated toner amount CT and a previously set lowermost toner amount LT with each other. When it is determined that the calculated toner amount CT is larger than the lowermost toner amount LT, it is determined that the proper amount of toner is left in the toner container 30Y, 30M, 30C, 30K. In this case, the process returns to the operation 201 in order to normally perform printing. When it is determined the calculated toner amount CT is not larger than the lowermost toner amount LT, it is determined that the proper amount of toner is not left in the corresponding toner container 30Y, 30M, 30C, 30K to display a message for exchanging the toner container on the display unit 105 (operation 213). However, it is understood that operation 215 need not be performed prior to operation 219, such as where replacement of the toner container 30Y, 30M, 30C, 30K is not confirmed until after it is determined that the toner container 30Y, 30M, 30C, 30K hole is not plugged.
It is determined whether to exchange the toner container 30 after the message for exchanging the corresponding toner container 30Y, 30M, 30C, 30K is displayed (operation 215). While not required in all aspects, it is determined whether to exchange the toner container 30Y, 30M, 30C, 30K by a unit for detecting the exchange of the toner container 30Y, 30M, 30C, 30K that is adopted in the method of separating the toner container 30Y, 30M, 30C, 30K from the corresponding developing device main body 20Y, 20M, 20C, 20K. It is preferable, but not required, that a mounting signal is applied to the printer controller 100 by a switch (not shown) when the corresponding toner container 30Y, 30M, 30C, 30K is mounted. However, it is not limited to the above. A unit whose mounting is recognized by the printer controller 100 may be adopted. A conventionally developed unit may be used and those skilled in the art can understand the unit although detailed description is omitted.
When it is determined in the operation 215 that the toner container 30Y, 30M, 30C, 30K is exchanged with a new toner container 30Y, 30M, 30C, 30K, the printer controller 100 resets the total driving number of times of the solenoid accumulated in the counting memory 103-2 in operation 216, and the process returns to the operation 201 in order to normally perform printing.
When it is determined in the operation 215 that the toner container 30Y, 30M, 30C, 30K is not exchanged with a new toner container (that is, the toner container 30Y, 30M, 30C, 30K is not exchanged with a new toner container 30 such as due to the carelessness of a user although the message for exchanging the toner container is displayed on the display unit 105), it is possible to perform printing in accordance with the printing command using the toner in the corresponding developing device main body 20Y, 20M, 20C, 20K. At this time, since the toner is not stably supplied from the toner container 30Y, 30M, 30C, 30K, the printer controller 100 checks the generation of the error of the toner sensor 42. That is, while printing is performed in response to the printing command, the printer controller 100 obtains the sensor value from the toner sensor 42 many times and averages the obtained sensor values to calculate the amount of the toner left in the developing device main body 20217.
It is determined whether the calculated developing device toner amount DT is no less than 250 (operation 219). When it is determined that the developing device toner amount DT is no less than 250, the table T of the storage unit 106 is detected to find the error code E2 and the error code E2 is displayed on the display unit 105 so that the user repair the toner supplying hole of the developing device 220.
When the calculated developing device toner amount DT is smaller than 250, it is determined whether the developing device toner amount DT is fixed to a uniform value (operation 221). When it is determined the developing device toner amount DT is fixed, the table T of the storage unit 106 is detected to find the error code E3 and the error code E3 is displayed on the display unit 105 so that the user can repair the toner sensor 42 (operation 222).
When it is determined in the operation 221 that the developing device toner amount DT is not fixed, it is determined whether the developing device toner amount DT is no more than a uniform value Te (for example, 30) (operation 223). When it is determined that the calculated developing device toner amount DT is larger than Te, since it is determined that the proper amount of toner is left in the developing device main body 20, printing is performed using the toner (operation 224). Then, the process returns to the operation 215.
When it is determined in the operation 223 that the calculated developing device toner amount DT is no more than Te, it is determined whether the calculated developing device toner amount DT is no more than 15 (operation 225).
When it is determined in the operation 225 that the calculated developing device toner amount DT is no more than 15, the table T of the storage unit 106 is detected to find the plurality of corresponding error codes E1, E4, and E5 and to display the error codes E1, E4, and E5 on the display unit 105 so that the user examine the error codes E1, E4, and E5 and take measures corresponding to the error codes E1, E4, and E5 (operation 226).
When it is determined in the operation 225 that the calculated developing device toner amount DT is larger than 15 and no more than Te, the table T of the storage unit 106 is detected to display the error code E4 on the display unit 105 so that the user recognizes that the toner in the corresponding developing device main body 20Y, 20M, 20C, 20K is insufficient and that printing quality may deteriorate to prevent the user from unnecessarily performing printing (operation 227).
As described above, according to aspects of the present invention, when printing is performed using the toner left in the developing device main body in a state where the amount of the toner in the toner container is insufficient so that it is difficult to supply the toner to the developing device main body, various error factors are recognized in accordance with the output values of the toner sensor to be displayed so that the user take measures corresponding to the error factors. Therefore, it is possible to improve the reliability of the toner sensor.
While described in terms of a cartridge with a separate structure in which the toner container is separate from the main body, it is understood that aspects of the invention can be implemented using a monolithic structure in which the toner is stored in the developing cartridge. Moreover, it is understood that aspects of the invention can be implemented as software encoded on one or more computer readable media and read by a computer, a controller, or a microprocessor.
Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-99875 | Oct 2006 | KR | national |
