JP4678213B2 - Toner supply device - Google Patents

Description

  The present invention relates to a toner replenishing device, and more particularly, to a toner replenishing device provided in an image forming apparatus using electrophotographic technology.

  In an image forming apparatus using an electrophotographic technology such as an electrophotographic copying machine or a laser printer, a reserve is provided to supply toner (developer) to a developing unit that develops an electrostatic latent image formed on a photosensitive member. A toner replenishing device including a tank (toner hopper) and a toner cartridge is provided. In addition, the reserve tank is provided with a toner sensor for detecting the remaining amount of toner. When the remaining amount of toner in the reserve tank and the toner cartridge becomes small (below a predetermined amount), it is detected. The necessity is displayed on the display of the image forming apparatus to notify the operator (for example, see Patent Document 1).

  However, in such a system using a sensor for toner detection for notification of cartridge replacement (warning display), as shown in FIG. 7A, when a new toner cartridge 100 is installed in the reserve tank 102. Since the toner filling amount (TN) in the cartridge is large, the fluidity of the toner is poor, and the amount of toner dropped and supplied to the reserve tank 102 by driving the cartridge immediately after replacement may not be stable (arrow T).

  Further, at this time, since the inside of the reserve tank 102 (near the toner sensor 104) is empty, as shown in FIG. 7B, the dropped toner TN is easily spread in the tank, and the toner TN becomes the toner TN. It takes time to accumulate (deposit) near the sensor 104 and pressurize the toner sensor 104. Further, the toner detection may become unstable because the toner TN is not sufficiently accumulated in the vicinity of the toner sensor 104 only by driving the cartridge for a predetermined time immediately after the replacement.

  As a result, accurate toner detection by the toner sensor 104 is delayed, and although the cartridge is replaced, a notification for prompting replacement of the cartridge is issued again, which confused the operator. In particular, in recent years, fluidity tends to deteriorate due to the reduction in the particle size and spheroidization of the toner accompanying higher image quality, and thus erroneous notification due to toner detection delay (response delay) immediately after cartridge replacement is likely to occur. Improvement is desired.

On the other hand, there has been proposed a technique for forcibly stopping the notification operation for prompting the replacement of the cartridge until a predetermined time elapses or a predetermined number of images are formed after the replacement of the toner cartridge. (For example, refer to Patent Document 2).
JP-A-8-160734 JP 2003-215902 A

  However, in the above-described technique, the toner is used up while the notification operation is stopped, for example, when it is not a new product and is replaced with a used toner cartridge, particularly in the case of a cartridge with a small amount of remaining toner. In such a case, there is a problem that the density of the image is lowered.

  In view of the above-described facts, an object of the present invention is to provide a toner replenishing device capable of preventing a decrease in image density that occurs immediately after replacement of a toner cartridge and an erroneous notification due to toner detection delay.

In order to achieve the above object, an invention according to claim 1 is provided in an image forming apparatus, and a toner replenishing device for replenishing toner used for image formation to a developing device of the image forming apparatus contains toner. A toner cartridge, and a reserve tank for storing the toner supplied from the toner cartridge through the intake port and supplying the toner to the developing unit when the toner cartridge is attached. A toner detecting means provided in a toner supply path of the reserve tank and below the intake port for detecting a remaining amount of toner; a toner supplying means for supplying toner from the toner cartridge to the reserve tank; conveying the toner from the lower side of the inlet of the reservoir tank to the developing device, the toner replenishing means for replenishing Control means for controlling the drive of the toner supply means and the toner replenishment means, and for determining the replacement timing of the toner cartridge based on the detection information by the toner detection means, the control means comprising the reserve After the toner cartridge is installed in the tank, the toner supply means is driven until the toner detection means detects the presence of toner, and after the toner is supplied to the reserve tank, the toner supply means is driven. And after the supplied toner is moved to the downstream side of the toner detection means, the toner supply means is stopped, and the toner supplied by the toner supply means is accumulated in the vicinity of the toner detection means. It is said.

  According to the first aspect of the present invention, when a toner cartridge containing toner to be supplied to the developing device of the image forming apparatus is mounted on the reserve tank, the control means drives the toner supply means and the toner supply means. As a result, the time until the toner supplied from the toner cartridge to the reserve tank accumulates in the vicinity of the toner detection means in the reserve tank is shortened, and the toner detection by the toner detection means after the toner cartridge is mounted is accelerated. Therefore, for example, when the notification operation for prompting the replacement of the cartridge is forcibly stopped after the replacement of the toner cartridge, it is possible to prevent a decrease in the image density that occurs immediately after the replacement of the cartridge, and further, an erroneous notification due to a delay in detecting the toner. Can be prevented.

Furthermore, in the first aspect of the invention, in the driving of the toner replenishing means, the control means controls, for example, the driving time of the toner replenishing means, and the toner that moves to the developing device side in the reserve tank is detected by the toner detecting means. After the toner is moved to the downstream side, the toner supply means is stopped. As a result, toner is deposited on the downstream side of the toner detection means, and the accumulated toner is blocked so that the toner supplied from the toner cartridge to the reserve tank does not flow downstream. Accordingly, the toner is quickly and reliably accumulated in the vicinity of the toner detection means, and the detection delay of the toner can be prevented more reliably.

Invention according to claim 2, in the toner replenishing device of claim 1, wherein the control means is characterized in that for continuously driving said toner supplying means.

According to a third aspect of the present invention, in the toner replenishing device according to the first aspect, the control unit temporarily stops the toner supplying unit while the toner replenishing unit is driven.

According to a fourth aspect of the present invention, in the toner replenishing device according to any one of the first to third aspects, the toner replenishing means is continuously driven.

According to the fourth aspect of the present invention, since the toner supplied to the reserve tank is continuously moved in the tank, it is accumulated / deposited in a short time.

According to a fifth aspect of the present invention, in the toner replenishing device according to any one of the first to third aspects, the toner replenishing means is intermittently driven.

According to the fifth aspect of the present invention, since the toner supplied to the reserve tank is intermittently moved within the tank, for example, the toner detection means detects the toner supplied to the reserve tank, and a series of operations is completed. In the meantime, it is possible to prevent the developer from being replenished with more toner than necessary. As a result, it is possible to prevent a secondary failure caused by such excessive toner supply.

According to a sixth aspect of the invention, in the toner replenishing device according to any one of the first to fifth aspects, the toner supply means is operated at a higher speed during a predetermined period after the toner cartridge is installed than after the predetermined period. It is characterized by being driven.

According to the sixth aspect of the present invention, the toner supply means is driven at a high speed for a predetermined period after the toner cartridge is mounted, even if a new toner cartridge has poor toner fluidity due to a large amount of toner in the cartridge. Thus, the toner is stably supplied to the reserve tank. Thereby, the time required for toner detection can be further shortened.

  Since the toner replenishing device according to the present invention has the above-described configuration, it is possible to prevent the image density reduction that occurs immediately after the replacement of the toner cartridge and erroneous notification due to toner detection delay.

  Hereinafter, a toner replenishing device according to an embodiment of the present invention will be described with reference to the drawings. Note that the toner replenishing device of this embodiment is a device that is provided in an electrophotographic image forming apparatus and replenishes toner to the developing device.

  The toner replenishing device 10 according to the present embodiment shown in FIGS. 1 and 2 includes a toner cartridge 12 in which toner TN is housed, and the toner cartridge 12 can be attached to and detached from the upper part. A reserve tank 14 is provided for replenishing the toner supplied from the image forming apparatus to the developing unit of the image forming apparatus while preliminarily containing the toner.

  The toner cartridge 12 is formed with a discharge port 16 for discharging toner at the lower end of the outer peripheral surface, and a metal wire such as stainless steel is bent into a spiral shape inside the cartridge containing the toner TN. The agitator 18 formed in this manner is rotatably provided.

  When the toner cartridge 12 is mounted on the reserve tank 14, one end of the agitator 18 is connected to the cartridge motor 20. The cartridge motor 20 is connected to a control unit 50 that controls the operation of each unit of the toner replenishing device 10, and is driven and controlled by the control unit 50.

  As a result, when the cartridge motor 20 is driven to rotate by being controlled by the control unit 50, the agitator 18 is rotated, and the toner in the toner cartridge 12 is conveyed to the discharge port 16 side while being stirred by the agitator 18, and downward from the discharge port 16. (Arrow A in FIGS. 1 and 2).

  In the reserve tank 14, an intake port 22 corresponding to the discharge port 16 of the toner cartridge 12 is formed in the vicinity of the corner on the upper surface. The toner discharged from the toner cartridge 12 is taken into the reserve tank 14 from the intake port 22. Further, a supply port 24 is formed at the center of the side surface opposite to the intake port 22, and this supply port 24 is connected to a developing device G provided in the image forming apparatus.

  Inside the reserve tank 14, two tank chambers 28 and 30 are provided on both sides of a partition wall 26 extending in the center. These tank chambers 28 and 30 are communicated with each other through openings 32 and 34 formed at one end and the other end of the partition wall 26. Further, the discharge port 16 communicates with only one tank chamber 28, and the supply port 24 communicates with the tank chamber 28 and the tank chamber 30 through the opening 34.

  The tank chambers 28 and 30 are rotatably provided with two spiral augers 36 and 38 disposed in parallel with the partition wall 26 therebetween. The spiral augers 36 and 38 are connected to a reserve tank motor 40, and the reserve tank motor 40 is also connected to the control unit 50.

  Accordingly, when the reserve tank motor 40 is driven to rotate under the control of the control unit 50, the spiral augers 36 and 38 rotate, and the toner in the tank chamber 28 supplied from the reserve tank 14 is stirred by the spiral auger 36. It is conveyed to the opening 34 and the supply port 24 side (arrow B in FIG. 2) and moves to the tank chamber 30 side through the opening 34 (arrow C in FIG. 2), or is supplied from the supply port 24 to the developing device. (Supply) (arrow D in FIG. 2). The toner that has entered the tank chamber 30 is conveyed to the opening 32 side while being agitated by the spiral auger 38 (arrow E in FIG. 2), and returns to the tank chamber 28 through the opening 32 ( Arrow F) in FIG.

  In the tank chamber 28 of the reserve tank 14, a toner sensor (pressure sensor) 42 is provided below the intake port 22. This toner sensor 42 is connected to the control unit 50 described above, and detects the presence or absence of toner existing near the lower side of the intake port 22 in the tank chamber 28 by the pressure received from the toner, and detects according to the pressure. The signal is output to the control unit 50. Specifically, toner detection / non-detection is output by a High / Low signal. The toner sensor 42 detects the remaining amount of toner in the reserve tank 14 and the toner cartridge 12.

  Further, the reserve tank 14 is provided with a memory 46 built in the toner cartridge 12 and an antenna 44 for transmitting and receiving data by wireless communication. The antenna 44 is connected to the control unit 50. Data indicating an ID number (identification information) unique to the cartridge is stored in advance in the memory 46 of the toner cartridge 12. When the toner cartridge 12 is mounted on the reserve tank 14, the control unit 50 is stored in the memory 46. Various data received from the antenna 44 and stored in a memory provided in the control unit 50.

  In addition, the control unit 50 manages the usage history of the toner cartridge 12 and data (toner cartridge drive) regarding the drive time of the cartridge motor 20 driven by the toner replenishment operation described above for the toner cartridge 12 that has acquired the ID number. (Accumulated time data) and data related to the drive time of the reserve tank motor 40 (reserve tank drive accumulated time data) are stored. Then, the driving time data of each motor is transmitted from the antenna 44 and stored in the memory 46. As a result, the service center or the like that has collected the used toner cartridge 12 reads the data stored in the memory 46 and collects the usage history information of the toner cartridge 12, and the user uses up the cartridge from the information, for example. This makes it possible to grasp the tendency of the cartridge replacement time, such as whether to replace the cartridge before replacement or before replacement.

  Next, the operation and action of the toner replenishing device 10 configured as described above will be described.

  In the image forming apparatus including the toner replenishing device 10 of the present embodiment, when the toner is consumed by the developing device G in association with image formation, the reserve auger motor 40 is driven to rotate the spiral augers 36 and 38 and consumed. An amount of toner is supplied from the reserve tank 14 to the developing device G. Further, when the amount of toner in the reserve tank 14 decreases with the replenishment, the pressure on the toner sensor 42 due to the toner in the reserve tank 14 is weakened, and the toner detection sensitivity of the toner sensor 42 is lowered. The toner sensor 42 outputs a Low signal indicating a toner non-detection state. When the Low signal is continuously input a predetermined number of times (for example, 5 times), the cartridge motor 20 is driven. Then, the agitator 18 is rotated to supply the toner in the toner cartridge 12 to the reserve tank 14.

  In such a toner replenishing operation, when the amount of toner in the toner cartridge 12 decreases, the amount of toner supplied from the toner cartridge 12 to the reserve tank 14 gradually decreases. As a result, the toner detection sensitivity of the toner sensor 42 decreases, and the toner sensor 42 frequently outputs a Low signal, so that a toner amount that can be detected by the toner sensor 42 can be supplied even when the cartridge is driven. Disappear.

  Then, the toner non-detection state by the toner sensor 42 continues, and as shown in FIG. 3, a first threshold value (near empty warning display threshold value) in which the cumulative time of the Low signal input to the control unit 50 is preset. If it exceeds, the control unit 50 determines that the toner cartridge 12 is approaching empty, and causes the display (not shown) of the image forming apparatus to display “near empty warning”.

  Here, when the toner cartridge 12 is continuously used, the accumulated time of the Low signal input to the control unit 50 further increases. When the accumulated time exceeds a second threshold (empty warning display threshold) set in advance higher than the first threshold by a predetermined value, the control unit 50 causes the toner cartridge 12 to be almost empty. The “empty warning” is displayed on the display of the image forming apparatus.

  In the graph shown in FIG. 3, the cumulative addition of the Low signal (toner non-detection) is indicated by a positive vector, and the cumulative addition of the High signal (toner detection) is indicated by a negative vector.

  Here, as shown in FIG. 3, when the toner cartridge 12 is replaced, that is, as shown in FIG. 4A, a new toner cartridge 12 is loaded into the image forming apparatus and stored in the reserve tank 14. When mounted, the control unit 50 drives the cartridge motor 20 for 20 seconds to rotate the agitator 18 as shown in FIG. 5, and the new toner cartridge 12 in the new toner cartridge 12 as shown in FIG. 4B. The toner TN is supplied to the reserve tank 14. Here, the toner TN enters the reserve tank 14 from the discharge port 16 of the toner cartridge 12 through the intake port 22 and falls to the vicinity of the toner sensor 42.

  Further, the controller 50 drives the reserve tank motor 40 for 5 seconds to rotate the spiral auger 36 during the drive of the cartridge motor 20, specifically, 10 seconds after the start of the drive of the cartridge motor 20. Then, the toner TN dropped in the vicinity of the toner sensor 42 moves to the downstream side of the toner sensor 42 (in the direction of supplying toner to the developing unit G) as shown in FIG. And deposited in a wall shape (dam shape).

  Further, after the wall-shaped toner TND is formed, the toner TN supplied to the reserve tank 14 is blocked by the toner TND so as not to flow downstream by continuing driving of the cartridge motor 20. When the drive of the cartridge motor 20 is stopped 5 seconds after the drive of the reserve tank motor 40 is stopped, a large amount of toner TN is accumulated in the vicinity of the toner sensor 42 as shown in FIG. Is pressurized by the toner TN and outputs a High signal indicating toner detection.

  Here, conventionally, it takes time until the toner dropped and supplied to the reserve tank spreads in the tank and pressurizes the toner sensor, or the toner is sufficiently accumulated in the vicinity of the toner sensor only by driving the cartridge for a predetermined time. Therefore, the toner detection may become unstable, and therefore accurate toner detection by the toner sensor is delayed, and even after the cartridge replacement, as shown by the NG side graph line in FIG. It increased again, and the near empty warning / empty warning may be erroneously notified.

  On the other hand, in the present embodiment, the toner sensor 42 quickly and reliably detects the toner supplied from the toner cartridge 12 to the reserve tank 14, and therefore, as indicated by the graph line on the OK side in FIG. The accumulated time of the signal gradually decreases, and the near empty warning / empty warning is not erroneously notified.

  As described above, in the toner replenishing device 10 of this embodiment, when the toner cartridge 12 is attached to the reserve tank 14, the control unit 50 drives the cartridge motor 20 and the agitator 18, the reserve tank motor 40 and the spiral auger 36. . Thereby, the time until the toner supplied from the toner cartridge 12 to the reserve tank 14 is accumulated in the reserve tank 14 near the toner sensor 42 is shortened, and the toner detection by the toner sensor 42 after the cartridge replacement is accelerated. Therefore, there is no decrease in image density caused by forcibly stopping the notification operation after cartridge replacement as in the prior art, and it is possible to prevent erroneous notification due to toner detection delay.

  In the present embodiment, the controller 50 controls the drive time of the reserve tank motor 40 in the drive on the reserve tank 14 side, and moves the toner to be moved to the developing device G side in the tank to the downstream side of the toner sensor 42. Since the reserve tank motor 40 is stopped after the movement, the toner is accumulated in a wall shape on the downstream side of the toner sensor 42, and is then supplied from the toner cartridge 12 to the reserve tank 14 by the accumulated toner. The blocked toner is blocked so that it does not flow downstream. Accordingly, the toner is quickly and reliably accumulated in the vicinity of the toner sensor 42, and the toner detection delay can be prevented more reliably.

  Further, in this embodiment, when the cartridge motor 20 is driven, the reserve tank motor 40 is also driven, and each motor is driven by providing an overlapping period, so that each motor is driven without providing an overlapping period. The time until the toner sensor 42 first detects toner can be shortened (responsiveness can be improved). Further, here, since the toner supplied to the reserve tank 14 is continuously moved in the tank, it is accumulated / deposited in a short time.

  In the present embodiment, the reserve tank motor 40 is continuously driven. However, this may be intermittent driving as shown in FIG. In the example shown in FIG. 6, the operation of driving the reserve tank motor 40 for 1 second and stopping the drive for 1 second is repeated for 9 seconds (the total motor drive time is 5 seconds). In the case of such intermittent drive control, since the toner supplied to the reserve tank 14 is intermittently moved in the tank, for example, the toner sensor 42 detects the toner supplied to the reserve tank 14, Until the series of operations is completed, it is possible to prevent the developer G from being replenished with more toner than necessary. As a result, it is possible to prevent such a secondary failure caused by excessive toner supply.

  In this embodiment, the reserve tank motor 40 is driven for a predetermined time (5 seconds) while the cartridge motor 20 is being driven (20 seconds), and each motor is driven with an overlapping period. Each motor may be driven in different periods, such as temporarily stopping the cartridge motor 20 when the reserve tank motor 40 is driven. In such a case, or when driving the reserve tank motor 40 after a predetermined time (10 seconds) from the start of driving of the cartridge motor 20 as in this embodiment, when the driving of the cartridge motor 20 is started, the reserve is started. Since the tank motor 40 is stopped, the toner supply position (dropping position) in the reserve tank motor 40 is fixed. Then, the accumulated toner is reliably formed by driving the reserve tank motor 40 after the toner supply (after the driving of the cartridge motor 20 is stopped) or during the toner supply (while the cartridge motor 20 is being driven).

  Further, in the toner replenishing device 10 of the present embodiment, the predetermined period after cartridge replacement is, for example, after the predetermined period, from the toner cartridge 12 to the reserve tank 14 accompanying toner replenishment from the reserve tank 14 to the developing device G. The cartridge motor 20 may be driven at a higher speed than during the toner supply operation (when the normal cartridge is driven). In that case, even if a new toner cartridge 12 whose toner fluidity deteriorates due to a large amount of toner in the cartridge, the cartridge motor 20 is driven at a high speed for a predetermined period after the cartridge replacement, so that the toner is reserved. The tank 14 is stably supplied. Thereby, the time required for toner detection is further shortened.

  As mentioned above, although this invention was demonstrated in detail by specific embodiment mentioned above, this invention is not limited to that embodiment, Various other forms can be implemented within the scope of the present invention.

  For example, in the above-described embodiment, the drive time of the reserve tank motor 40 is controlled in order to move the toner to the downstream side of the toner sensor 42 and stop (accumulate). It is also possible to control the rotation amount of 36.

1 is a configuration diagram illustrating an overall configuration of a toner supply device according to an embodiment of the present invention. It is a perspective view showing a reserve tank of a toner replenishing device according to an embodiment of the present invention. FIG. 6 is a graph showing a warning display operation performed based on toner detection (low signal accumulated time of toner sensor) in the toner supply device according to the embodiment of the present invention. (A)-(D) are operation | movement explanatory drawings for demonstrating the toner detection operation | movement performed after cartridge replacement | exchange in the toner supply apparatus which concerns on one Embodiment of this invention. 6 is a timing chart showing drive timing of a motor driven after cartridge replacement in the toner supply device according to the embodiment of the present invention. It is a timing chart which shows the modification of FIG. (A) and (B) are operation explanatory views for explaining a toner detection operation performed after cartridge replacement in a conventional toner replenishing device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Toner supply apparatus 12 Toner cartridge 14 Reserve tank 18 Agitator (toner supply means)
20 Cartridge motor (toner supply means)
36 Spiral auger (toner supply means)
40 reserve tank motor (toner supply means)
42 Toner sensor (toner detection means)
50 Control unit (control means)
G Developer TN Toner

Claims (6)

In a toner replenishing device provided in an image forming apparatus for replenishing toner used for image formation to a developing device of the image forming apparatus,
A toner cartridge containing toner;
A reserve tank for storing the toner supplied from the toner cartridge via the intake port in a mounted state of the toner cartridge and replenishing the developing device, the toner cartridge being detachable;
A toner detecting means provided in a toner supply path of the reserve tank and below the intake port for detecting a remaining amount of toner;
Toner supply means for supplying toner from the toner cartridge to the reserve tank;
Toner replenishing means for transporting and replenishing toner from below the intake port in the reserve tank to the developer;
Control means for controlling the drive of the toner supply means and the toner replenishing means, and for determining the replacement timing of the toner cartridge based on detection information by the toner detection means;
Have
Wherein, after the toner cartridge in the reserve tank is mounted, until the toner detection means for detecting a state there the toner, the drives the toner supplying unit, after supplying the toner to the reserve tank And driving the toner replenishing means to move the supplied toner to the downstream side of the toner detecting means, and then stopping the toner replenishing means to bring the toner supplied by the toner supplying means near the toner detecting means. A toner replenishing device that accumulates toner. The toner replenishing apparatus according to claim 1 , wherein the control unit continuously drives the toner supply unit. 2. The toner replenishing apparatus according to claim 1 , wherein the control unit temporarily stops the toner supply unit while the toner replenishing unit is driven . The toner replenishing device according to any one of claims 1 to 3, characterized in that for continuously driving said toner replenishing means. The toner replenishing device according to any one of claims 1 to 3, characterized in that to intermittently drive the said toner replenishing means. Wherein the predetermined period of time after the toner cartridge mounted, the toner supply device according to any one of claims 1 to 5, characterized in that said toner supplying means to high-speed driving than its subsequent predetermined period.

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