Abstract:
A method and apparatus for discriminating bottle types, for stirring the toner, and for detecting the amount of toner remaining in the toner bottle. A toner bottle is adapted to fit the apparatus for discriminating toner bottle types, and a toner bottle is adapted for the apparatus for stirring toner. The genuineness of the toner bottle product is checked by sensing a rib assumed to be formed with a predetermined length on the outer surface of the toner bottle. Toner is stirred by continuously rotating the toner bottle in forward and reverse directions. The toner bottle can be easily rotated in the forward and reverse directions by sensing the rib of the toner bottle by using the sensor. Since the load of rotation of the toner bottle changes in accordance with the amount of remaining toner, the rotational speed of the toner bottle is sensed by using the sensor to check whether toner is close to empty.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a method and apparatus for discriminating toner bottle types, stirring toner, and detecting the amount of remaining toner, a toner bottle adapted to fit the apparatus for discriminating toner bottle types, and a toner bottle adapted for the apparatus for stirring toner. 
     A copying machine using a laser beam performs a copying process in which the surface of a photosensitive drum is negatively charged and exposed to a laser beam on the basis of an image signal, negatively charged toner is attracted to the exposed portion to form a visual image, and this visual image is transferred onto a transfer sheet and fixed on it. 
     To replenish the copying machine with toner, a toner bottle containing toner and a driving unit for rotating this toner bottle are used. 
     However, conventional copying machines have the following several problems about a toner bottle. 
     First, it is impossible to reliably eliminate the use of toner bottles other than genuine products by a simple method. 
     Second, it is necessary to stir toner in order to prevent inclination and gathering of toner in a toner bottle and thereby stabilize the replenishment. However, stirring of toner cannot be performed by a simple method. 
     Third, the amount of remaining toner in a toner bottle cannot be detected in real time. Conventionally, the amount of remaining toner is detected by, e.g., the following method. When a developing unit containing toner and a carrier for charging the toner detects a deficiency of the toner amount, it outputs a signal for requesting replenishment of toner from a toner bottle. If the deficiency of the toner amount does not improve although the signal is output three times, empty indication is performed to indicate that the toner bottle is empty. 
     However, this method cannot detect a toner deficiency in a toner bottle in real time. Hence, in some cases a toner deficiency is suddenly indicated and copying is interrupted during copying a large quantity of sheets. If this is the case, the operation is kept interrupted while the user who has started this large-quantity copying is away from the copying machine. 
     SUMMARY OF THE INVENTION 
     It is, therefore, the first object of the present invention to reliably eliminate the use of toner bottles other than genuine products by a simple method. 
     It is the second object of the present invention to stir toner in a toner bottle by a simple method. 
     It is the third object of the present invention to detect a toner deficiency in a toner bottle in real time to inform it before toner empty indication is performed, thereby improving the efficiency of copying. 
     According to the present invention, there is provided a method of discriminating toner bottle types, comprising the object sensing step of rotating a toner bottle, sensing an object to be sensed formed on an outer surface of the toner bottle and, if the object is not sensed, outputting information indicating abnormality, and the ratio discrimination step of checking, if the object is sensed, whether the object is formed at a predetermined ratio on the outer surface of the toner bottle, outputting information indicating abnormality if the object is not formed at the predetermined ratio, and outputting information indicating normality if the object is formed at the predetermined ratio. 
     In this method, the object ratio discrimination step can comprise the steps of detecting a first time interval from the timing at which the sensor senses one end portion of the object of the toner bottle in rotation to the timing at which the sensor senses the other end portion, detecting a second time interval from the timing at which the sensor senses the other end portion of the object to the timing at which the sensor senses the one end portion, and checking whether the object is formed over a predetermined length on the outer surface of the toner bottle by using the first and second time intervals. 
     In this method, the object ratio discrimination step may be performed with reference to the timing at which a first end portion of the object of the toner bottle in rotation is sensed and the timing at which a second end portion of the object is sensed. 
     An apparatus for discriminating toner bottle types according to the present invention comprises a motor for rotating a toner bottle, a motor driver for driving the motor, a sensor for sensing an object to be sensed formed in a predetermined portion of the toner bottle and outputting a sensor signal, and a CPU for controlling the motor driver and discriminating the toner bottle by using the sensor signal, wherein the CPU rotates the toner bottle by controlling the motor driver, senses the object assumed to be formed on an outer surface of the toner bottle by using the sensor, outputs information indicating abnormality if the object is not sensed, checks, if the object is sensed, whether the object is formed at a predetermined ratio on the outer surface of the toner bottle, outputs information indicating abnormality if the object is not formed at the predetermined ratio, and outputs information indicating normality if the object is formed at the predetermined ratio. 
     In order to check whether the object is formed at the predetermined ratio on the outer surface of the toner bottle, the CPU can detect a first time interval from the timing at which the sensor senses one end portion of the object of the toner bottle in rotation to the timing at which the sensor senses the other end portion, detect a second time interval from the timing at which the sensor senses the other end portion of the object to the timing at which the sensor senses the one end portion, and check whether the object is formed at the predetermined ratio on the outer surface of the toner bottle by using the first and second time intervals. 
     A toner bottle according to the present invention is so formed as to be adapted to fit the toner bottle type discriminating apparatus described above. 
     A method of stirring toner according to the present invention comprises the steps of rotating a toner bottle through a predetermined angle in a forward direction, and rotating the toner bottle through a predetermined angle in a reverse direction. 
     A method of stirring toner and discriminating toner bottle types according to the present invention comprises the steps of rotating a toner bottle through a predetermined angle in a forward direction, sensing an object to be sensed assumed to be formed on an outer surface of the toner bottle and, if the object is not sensed, outputting information indicating abnormality, and rotating the toner bottle through a predetermined angle in a reverse direction, sensing the object by using the sensor and, if the object is not sensed, outputting information indicating abnormality, wherein toner is stirred by rotating the toner bottle through the predetermined angles in the forward and reverse directions. 
     An apparatus for stirring toner and discriminating toner bottle types according to the present invention comprises a motor for rotating a toner bottle, a motor driver for driving the motor, a sensor for sensing an object to be sensed formed in a predetermined portion of the toner bottle and outputting a sensor signal, and a CPU for controlling the motor driver and receiving the sensor signal, wherein the CPU controls the motor driver to rotate the toner bottle through a predetermined angle in a forward direction, senses the object assumed to be formed on an outer surface of the toner bottle by using the sensor, outputs information indicating abnormality if the object is not sensed, rotates the toner bottle through a predetermined angle in a reverse direction, senses the object by using the sensor, and outputs information indicating abnormality if the object is not sensed. 
     A toner bottle according to the present invention is so formed as to be adapted to fit the toner stirring apparatus described above. 
     A method of detecting the amount of remaining toner according to the present invention comprises the steps of rotating a toner bottle and sensing the rotational speed by using a sensor, and detecting the amount of remaining toner in the toner bottle on the basis of the sensed rotational speed. 
     Alternatively, a method of detecting the amount of remaining toner according to the present invention comprises the steps of rotating a toner bottle, sensing one end portion of an object to be sensed of the toner bottle by using a sensor, and detecting a first time interval from the timing of sensing to the timing at which the sensor senses the other end portion, detecting a second time interval from the timing at which the sensor senses the other end portion of the object to the timing at which the sensor senses the one end portion, calculating the rotational speed of the toner bottle by using the first and second time intervals, and detecting the amount of remaining toner in the toner bottle on the basis of the calculated rotational speed. 
     An apparatus for detecting the amount of remaining toner according to the present invention comprises a motor for rotating a toner bottle, a motor driver for driving the motor, a sensor for sensing an object to be sensed formed in a predetermined portion of the toner bottle and outputting a sensor signal, and a CPU for controlling the motor driver and detecting the amount of remaining toner by using the sensor signal, wherein the CPU controls the motor driver to rotate the toner bottle by the motor and detects the amount of remaining toner in the toner bottle on the basis of the output sensor signal from the sensor. 
     The CPU can control the motor driver to rotate the toner bottle by the motor, sense one end portion of the object of the toner bottle by using the sensor, detect a first time interval from the timing of sensing to the timing at which the sensor senses the other end portion, detect a second time interval from the timing at which the sensor senses the other end portion of the object to the timing at which the sensor senses the one end portion, calculate the rotational speed of the toner bottle by using the first and second time intervals, and detect the amount of remaining toner in the toner bottle on the basis of the rotational speed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal sectional view showing an outline of the arrangement of a whole copying machine; 
         FIG. 2  is a perspective view showing a toner bottle and a driving unit in the copying machine; 
         FIG. 3  is a longitudinal sectional view showing a rotating mechanism in the driving unit; 
         FIG. 4  is a block diagram showing the configuration of a control circuit in a toner bottle type discriminating apparatus according to the first embodiment of the present invention, a toner stirring apparatus according to the second embodiment, and a remaining toner amount detecting apparatus according to the third embodiment; 
         FIG. 5  is a view for explaining a toner bottle and a sensor in the apparatuses according to the first, second, and third embodiments; 
         FIG. 6  is a timing chart showing an output waveform when the sensor senses a rib of the toner bottle; 
         FIG. 7  is a flow chart showing the procedure of the operation of a toner bottle type discriminating method and apparatus according to the first embodiment of the present invention; 
         FIG. 8  is a flow chart showing the procedure of the operation of a toner stirring method and apparatus according to the second embodiment of the present invention; 
         FIG. 9  is a graph showing the relationship between the remaining toner amount and the rotational speed of the toner bottle according to the third embodiment of the present invention; 
         FIG. 10  is a graph showing the relationship between the remaining toner amount and the possible number of copies according to the third embodiment of the present invention; 
         FIG. 11  is a flow chart showing the procedure of the operation of a remaining toner amount detecting method and apparatus according to the third embodiment of the present invention; and 
         FIG. 12  is a flow chart showing the continuation of the procedure of the operation of the remaining toner amount detection method and apparatus. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below with reference to the accompanying drawings. 
       FIG. 1  shows the arrangement of a whole copying machine. This copying machine  1  includes cassette paper feed units  2  containing a large number of transfer sheets in the lower portion of the machine. 
     The upper portion of the copying machine  1  includes an image reader  5  for reading an original, an automatic document feeder  6  for supplying an original to this image reader  5 , an image storage unit (not shown) for storing image data read by the image reader  5 , and a laser optical device  9  for extracting the stored image data and forming a visible image by irradiating an image forming unit  8  with a laser beam. 
     The image forming unit  8  is composed of a photosensitive drum  10 , a developing unit  11 , a cleaner  12 , a charger  13 , a discharge lamp  14 , and a transfer/separation charger  15 . The developing unit  11  has a toner bottle  16  and a driving unit for rotating the toner bottle  16 . 
       FIG. 2  shows the toner bottle  16  and the driving unit  17 . A cap  20  having a discharge port  21  is placed at an opening portion of the toner bottle  16 . A rib  24  is formed on a portion of the outer surface at the end portion away from the opening portion of the toner bottle  16 . This rib  24  has a predetermined positional relationship with the discharge port  21  of the cap  20 . 
     A rotating mechanism including driving gears and the like, which is a part of the driving unit  17  for rotating the toner bottle  16 , will be described below with reference to  FIGS. 2 and 3 . Referring to  FIG. 2 , the driving unit  17  includes a motor  27 , a pulley  29 , a belt  28  for transmitting the rotation of the motor  27  to the pulley  29 , a driving gear A  30  to which the rotation of the pulley  29  is transmitted, a driving gear B (not shown) to which the rotation of the driving gear A  30  is transmitted, a conveyor auger for converting the rotation of the driving gear B into linear motion, and a driving gear C  33  for converting the linear motion of the conveyor auger into rotation. Referring to  FIG. 3 , the driving unit  17  includes a driving gear D  34  for transmitting the rotation of the driving gear C  30 , a driving plate  36  attached to the rotating shaft of the driving gear D  34 , the driving gear D  34  attached to the driving plate  36  to slide along the axial direction, and a holder guide  37  attached to the driving plate  36  and rotated together with the driving plate  36  by the driving gear D  34 . The developing unit  11  has the toner bottle  16  and the driving unit  17  as described above. 
     The first, second, and third embodiments of the present invention include a control circuit shown in  FIG. 4  in order to control the rotation of the toner bottle  16  and perform processing such as discrimination. 
     This control circuit includes a CPU (Central Processing Unit)  101 , a ROM  104 , a RAM  105 , a sensor  102 , and a motor driver  103 . The CPU  101  manages the whole operation of the copying machine  1 . The ROM  104  stores programs for designating the operation procedure of the CPU  101 . The RAM  105  stores data and data is read out from the RAM  105  where necessary under the control of the CPU  101 . The sensor  102  senses the rib  24  of the toner bottle  16  and outputs a sensor signal to the CPU  101 . The motor driver  103  receives a control signal from the CPU  101  and drives the motor  27  for rotating the toner bottle  16 . 
     In accordance with the procedures to be described later with reference to flow charts, the CPU  101  outputs a control signal to the motor driver  103  and causes the motor driver  103  to drive the motor  27 . The motor  27  rotates the toner bottle  16 , and the sensor  102  senses the rib and outputs a sensor signal to the CPU  101 . On the basis of this sensor signal, the CPU  101  discriminates the type of the toner bottle  16 , controls the number of times of rotation of the toner bottle for the purpose of stirring toner, or detects the amount of remaining toner. 
     First, the procedure of discrimination performed by a toner bottle type discriminating apparatus according to the first embodiment of the present invention and a toner bottle adapted to fit this discriminating apparatus will be described below.  FIG. 5  shows the positional relationship between the sensor  102  and the rib  24  of the toner bottle  16 . The sensor  102  can be any sensor as long as it can sense the presence of the rib  24 . An optical sensor and a mechanical limit SW are examples. 
     It is also possible to adhere a magnetic material to the surface of a toner bottle and allow a magnetic sensor to sense this material. Alternatively, it is possible to attach an optically sensible mark such as a bar code to the surface of a toner bottle and permit an optical sensor to sense this mark. That is, it is only necessary to allow a sensor to sense a portion to be discriminated. 
     Let α be the angle at which the rib exists on the outer surface of the toner bottle  16  and β be the angle at which it does not exist. When a spiral is cut in the outer surface of the toner bottle  16  as shown in  FIG. 2 , the direction in which internal toner moves changes in accordance with the rotational direction. Therefore, the rotation of the toner bottle  16  includes forward rotation and reverse rotation. The forward rotation is rotation in a direction in which toner in the toner bottle  16  moves to the opening portion. The reverse rotation is rotation in a direction in which toner moves to the end portion opposite to the opening portion. 
       FIG. 6  shows an output waveform when the sensor  102  senses the rib  24  of the toner bottle  16  during rotation (regardless of whether it is forward rotation or reverse rotation). A high level is output in a period T 1  during which the sensor  102  senses the rib  24 . The output changes to low level in a period T 2  during which the sensor  102  does not sense the rib  24 . 
       FIG. 7  shows the procedure of toner bottle discrimination according to this embodiment. In step S 100 , the CPU  101  starts rotating the motor  27 . The direction of this rotation is the reverse direction. This is so because this operation is to discriminate whether the toner bottle is a genuine product, unlike the original toner bottle operation of replenishing toner to the developing unit, so it is necessary to prevent discharge of toner from the opening portion. 
     In step S 102 , the CPU  101  waits until the rotation of the toner bottle  16  becomes stable. During this interval, the CPU  101  does not check for the output from the sensor  102 . This is so because the time required for the rotation of the motor  27  to become a constant velocity rotation changes in accordance with the amount of remaining toner in the toner bottle  16 , so the CPU  101  cannot accurately measure the time of one rotation of the toner bottle. This phenomenon is significant when a brush motor is used as the motor  27 . 
     In step S 104 , after the rotation of the motor  27  has become stable, the CPU  101  checks for the output from the sensor  102 , thereby checking whether the output has changed from low level to high level. 
     In step S 106 , if the output from the sensor  102  has not changed from low level to high level within a predetermined time, i.e., if the rib  24  does not exist in a predetermined position of the toner bottle  16 , the CPU  101  determines that this toner bottle  16  is not a genuine product, and displays information indicating abnormality on a control panel. If the output from the sensor  102  has changed from low level to high level within the predetermined time, in step S 108  the CPU  101  starts measuring a time T 1  during which the high-level output is maintained. 
     In step S 110 , the CPU  101  checks for the output from the sensor  102  to check whether the output has changed from high level to low level. If the CPU  101  determines in step S 112  that the output has not changed from high level to low level within a predetermined time, the CPU  101  determines that the toner bottle  16  is not a genuine product, and displays information indicating abnormality on the control panel. If the output has changed from high level to low level within the predetermined time, a high-level output period T 1  is determined at this point. 
     In step S 114 , the CPU  101  starts measuring a time T 2  during which the output maintains low level. In step S 118 , the CPU  101  checks whether the output has changed from low level to high level within a predetermined time. If NO in step S 118 , the CPU  101  displays information indicating abnormality on the control panel. If the output has changed from low level to high level within the predetermined time, a low-level output period T 2  is determined at this point. 
     In step S 120 , the rotation of the motor  27  is stopped under the control of the CPU  101 . 
     In step S 122 , the CPU  101  calculates the angle α (=T 1 /(T 1 +T 2 )) at which the rib  24  exists by using the high-level output period T 1  and the low-level output period T 2 . 
     In this embodiment, the rib angle α is detected by using the high-level output period T 1  and the low-level output period T 2  of the sensor as parameters, and is used as a criterion. However, various criteria can also be formed by combining the timings of the leading and trailing edges of the sensor output signal. 
     In step S 124 , the CPU  101  checks whether the calculated angle α corresponds to a genuine product. If the angle α corresponds to a genuine product, the CPU  101  determines that this toner bottle is a genuine product, and completes the process. If the angle α does not correspond to a genuine product, the CPU  101  displays information indicating abnormality on the control panel and completes the process. 
     In this embodiment as described above, it is possible to discriminate whether a toner bottle is a genuine product by using a simple method. Also, different toner bottle destination versions (e.g., a domestic version, a US version, and an European version) can be set by setting several different angles α. 
     A toner stirring method and apparatus and a toner bottle adapted to fit the apparatus according to the second embodiment of the present invention will be described below.  FIG. 8  shows the procedure of this process. In step S 200 , a CPU  101  drives a motor to rotate a toner bottle  16 . This first rotational direction is a reverse direction. In step S 203 , the CPU  101  checks whether an output has changed to high level within a predetermined time. If NO in step S 203 , this means that the motor is locked, so the CPU  101  abnormally terminates the process. 
     In step S 202 , the CPU  101  checks whether the output from a sensor  102  has changed from high level to low level. 
     In step S 204 , the CPU  101  checks whether the output has changed from high level to low level within a predetermined time. If NO in step S 204 , the CPU  101  determines that the motor is locked, and abnormally terminates the process. 
     If the output has changed from high level to low level within the predetermined time, the CPU  101  stops the motor in step S 206 . 
     In step S 208 , the CPU  101  rotates the motor in a forward direction. 
     In step S 210 , the CPU  101  checks whether the sensor output has changed from high level to low level. 
     In step S 212 , the CPU  101  checks whether the output has changed from high level to low level within a predetermined time. If NO in step S 212 , the CPU  101  abnormally terminates the process. 
     If the output has changed from high level to low level within the predetermined time, the CPU  101  stops the motor in step S 214 . 
     In step S 216 , the CPU  101  checks whether the stirring operation has been performed twice. If the CPU  101  determined that the stirring operation has not been performed twice, the flow returns to step S 200 . If the CPU  101  determines that the stirring operation has been performed twice, the CPU  101  completes the process. 
     In the second embodiment described above, a toner stirring process can be performed by a simple method. 
     The number of times of the toner stirring operation is set to 2 in this embodiment, but this number of times can be freely set. When this is the case, the desired number of times is set as a stirring number N, and the stirring operation is repeated until this number is reached in step S 216 . 
     A remaining toner amount detecting method and apparatus and a toner bottle adapted to fit the apparatus according to the third embodiment of the present invention will be described below. In this embodiment, the amount of remaining toner is detected since the load of rotation of a toner bottle changes in accordance with the amount of remaining toner in the toner bottle. 
       FIG. 9  shows a change in the rotational speed when a toner bottle is rotated by giving it a fixed torque from the state in which the toner bottle is filled with toner to the state in which the remaining toner amount is 0 (toner empty). Let r 1  be the rotational speed when the toner bottle is full, r 3  be the rotational speed when the remaining toner amount is 0, and r 2  be the rotational speed when the remaining toner amount is a predetermined amount n (toner near empty) (g) close to 0. Also, let r be the rotational speed obtained by rotating the toner bottle when the remaining toner amount is m (g). 
       FIG. 10  shows the relationship between the remaining toner amount and the possible number of copies when a standard chart (a chart for use in testing with which the ratio of toner necessary to copy on one transfer material is approximately 6%) is used. Assume that the possible number of copies when the toner bottle is filled with toner is, e.g., 10,000, and the possible number of copies when the remaining toner amount is n (g) is, e.g., 2,000. 
     On the basis of the relationship between the remaining toner amount and the rotational speed shown in  FIG. 9 , when the rotational speed r detected becomes higher than the rotational speed r 2 , it is determined that toner empty is approached, and information indicating toner empty is displayed. 
       FIG. 11  shows the process procedure leading to a remaining toner amount check routine.  FIG. 12  shows the remaining toner amount check routine. 
     In step S 300 , a CPU  101  performs a copying operation. 
     In step S 302 , the CPU  101  counts the number of copies C for each copying. 
     In step S 304 , the CPU  101  checks whether the number of copies C exceeds a predetermined number of copies. If NO in step S 304 , the flow returns to step S 300 . If YES in step S 304 , the flow advances to the next step. 
     In step S 306 , the CPU  101  checks whether a developing unit has requested toner replenishment. If NO in step S 306 , the flow returns to step S 306 . If YES in step S 306 , the flow advances to a remaining toner amount check routine in step S 308 . 
     In step S 400  of  FIG. 12 , the CPU  101  replenishes toner. 
     In step S 402 , the CPU  101  drives a motor  27  to rotate a toner bottle  16 . The direction of this rotation is a forward direction because replenishment of toner is the purpose. 
     In step S 404 , the CPU  101  waits until the rotation of the toner bottle  16  becomes stable. 
     In step S 406 , the CPU  101  checks whether the output from a sensor  102  has changed from low level to high level. 
     In step S 408 , the CPU  101  starts measuring a time T 1  during which the sensor output maintains high level. 
     In step S 410 , the CPU  101  checks whether the sensor output has changed from high level to low level. The time T 1  is determined when the sensor output has changed. 
     In step S 412 , the CPU  101  starts measuring a time T 2  during which the sensor output maintains low level. 
     In step S 414 , the CPU  101  checks whether the sensor output has changed from low level to high level. The time T 2  is determined when the sensor output has changed. 
     In step S 416 , the CPU  101  stops the motor. 
     In step S 418 , the CPU  101  calculates the rotational speed r (=1/(T 1 +T 2 )) of the toner bottle. 
     In step S 420 , the CPU  101  checks whether the calculated rotational speed r is higher than the predetermined rotational speed r 2 . If the rotational speed r is equal to or lower than the predetermined rotational speed r 2 , the flow returns to step S 310  in the flow chart of  FIG. 11 , and the CPU  101  resets the counter of the number of copies C and completes the process. If the rotational speed r is higher than the predetermined rotational speed r 2 , the flow advances to step S 422 , and the CPU  101  display near empty. The flow then returns to step S 310  in the flow chart of  FIG. 11 , and the CPU  101  resets the counter of the number of copies C and completes the process. 
     In the third embodiment described above, the remaining toner amount can be detected in real time. Also, the remaining toner amount can be displayed in the state of near empty which is close to empty. 
     Each of the above embodiments is merely an example and hence does not restrict the present invention. The present invention can be modified without departing from the scope of right of the invention. For example, the outer shape of the toner bottle and the arrangement of the driving unit are not limited to those shown in  FIGS. 1  to  3 . Also, the shape of the rib formed on the outer surface of the toner bottle is not restricted to the one shown in  FIGS. 2  to  5  and can be deformed where necessary. In the second embodiment described above, both the toner stirring process and the toner bottle type discrimination process are performed. However, only the toner stirring process can also be performed. 
     Furthermore, when the CPU checks whether a toner bottle is a genuine product or whether toner is near empty, the result can be displayed on a dedicated screen or a screen for operations, such as a liquid crystal display or a CRT, commonly included in a copying machine.