JPS61248066A - Toner replenishing device - Google Patents

Abstract

PURPOSE:To remove the detection of malfunction due to wiper operation while keeping the volume of toner in a developing device at a fixed value and refreshing the surface of a toner sensor precisely by forming a toner residual detecting means, a control device for executing the sequence operation of an image forming device and a means for alarming toner empty status. CONSTITUTION:When toner in the developing part A is reduced, a toner sensor S is exposed, so that a replenishing roller 6 is rotated by a motor M and toner is dropped from a hopper part B. A lower agitation shaft 3 rotates at a slow speed synchronously with the rotation of a sleeve 1 so as to collect the toner to the sleeve side by an agitation rod 4 and sweep off the surface of the sensor S by a wiper 5. Even if toner is removed temporality from the surface of the sensor when toner exists, the toner is returned to the original status during one rotation of the wiper and toner replenishing operation is not executed. At the absence of toner, the wiper continues its work during the operating period of the replenishing motor even is the copying operation has been completed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner replenishing device for an image forming apparatus such as a copying machine or a laser beam printer.

(Description of the Prior Art) In laser beam printers and copying machines, magnetic toner or non-magnetic toner is used as a developer when printing images. This toner is attracted to and adheres to the charged area on the photoreceptor, and is then transferred onto copy paper to form an image. Therefore, the amount of toner consumed tends to be influenced by the density of the original image and the quality of the image information. Further, although toner is normally stored in the container of the container, only a certain amount can be accommodated.

Therefore, if the toner content in the constant button developer container is not managed, the toner will run out during copying and the copy will become blank. Therefore, it is necessary to provide a toner remaining amount detection device and replenish toner before the toner is completely used up.

In recent years, a small amount of toner replenishment method has been used to improve image quality. This is done by creating two accommodating parts in the developing container, with the first accommodating part serving as a toner accommodating chamber, and the second accommodating chamber having a developing sleeve and an agitating section, and stirring the toner inside the second container. The amount of toner in the second storage chamber is kept constant by replenishing toner from the first storage chamber by the amount consumed from the developing sleeve. The amount of triboelectric charge can be kept constant, and stable developing conditions can be obtained.Therefore, a detection device for the remaining amount of toner is provided in this second storage chamber, and this detection device can keep the amount of toner constant. Keep it.

In the method for replenishing a small amount of toner configured in this manner, as described above, it is necessary to perform fine replenishment according to the amount of toner consumed. Therefore, the timing for detecting the remaining amount of toner and the timing for supplying toner from the first storage chamber to the second storage chamber must be determined as appropriate while constantly monitoring the toner amount. In contrast to the conventional method of detecting and replenishing the remaining amount of toner after a copy is completed or when the copier is stopped, this new method uses a method of replenishing a small amount of toner to improve image quality, and a new method that increases the number of copies per 1,000 sheets at a time. This is due to the increasing number of high-end machines that can make large numbers of copies.

Currently, the following sensors are generally used to detect the amount of toner. For example, a dielectric material is pasted on a thin metal disk to form a piezoelectric vibrator, which is then formed as a feedback element on an oscillation circuit to cause oscillation at a natural frequency as the mechanical resonance frequency of the piezoelectric vibrator. The surface of this vibrator is brought into contact with a toner detection part in the developer container, etc., and depending on the toner contact situation, the difference between the mechanical resonance frequency that the piezoelectric vibrator originally has and the resonance frequency due to toner contact is detected. It is used to detect the amount. Such a toner sensor is set in the developing device, the amount of toner adhering to the surface of this sensor is detected, and the toner is dropped from the first container at the top to the container with the developing sleeve at the bottom, By supplying the toner to a point where it comes into contact with a part of the sensor, the consumed amount is replenished, and the amount of toner is kept constant by returning the toner.

(Problems to be Solved by the Invention) Conventionally, in a copying apparatus configured in this manner, this operation was likely to occur. This operation is due to the fact that in order to accurately detect toner 1 adhering to the surface of a part of the sensor, a means is employed to constantly clean the sensor surface at regular intervals.

This cleaning means is used to remove toner from the entire developer container due to toner adhering to the sensor surface.
However, this is to prevent the sensor from determining that there is toner due to a small amount of attached toner. Such means usually include a blade that mechanically scrapes the sensor surface, a spring tongue, or a thin metal rod, and the configuration of this part is determined by the density of the toner and the particle size of the powder. Such leaning means are usually attached to the stirring means.

One of these operations is to detect that there is no toner even though there is toner. The problem is that the toner on the toner detection surface is removed by the stirring means and the toner temporarily disappears from the detection surface, causing excess toner to accumulate in the container where the sensor is placed, making it impossible to perform copying operations with proper image density. This has the disadvantage of causing the toner to solidify, and furthermore, it may cause an accident in which the developing device is damaged due to the solidification of the toner.

Second, there is a malfunction in which the presence of toner is detected even though there is no toner. This is because, as mentioned above, if the stirring means stops at the position of the toner detection surface, the sensor detects that there is toner. (Objective of the Invention) The present invention eliminates the above-mentioned drawbacks. In addition, the toner replenishing device in the image forming apparatus is designed to forcibly stop the copying operation and warn the user to replenish toner if it detects that there is no toner during close-up close-up photography. It is intended for the purpose of providing.

(Means for Solving the Problems) The present invention includes a toner remaining amount detection means disposed in a developing device of a UIIF* forming apparatus, a control device that causes the image forming apparatus to perform sequence operations, and a system that warns of an out-of-toner state. When the control device receives the output of the remaining toner amount detecting means to control the image forming operation and warn of the out-of-toner state, the remaining amount of toner is detected by the developer carrier during the image forming operation. When the toner is rotated, the toner replenishment operation is performed after detecting that there is no toner for a certain period of time, and if the toner does not become available within a certain period of time after the start of this replenishment operation, the image forming operation is stopped or after a certain number of sheets have been counted. After the forming operation is forcibly stopped, a toner out warning is displayed, or the image forming operation is stopped until the image forming operation can be ended within a certain period of time after starting the replenishment operation (even if toner is present). A toner replenishing device is characterized in that it continues and if there is toner, it stops, and if there is no toner, a toner out warning is displayed (Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

Figure @1 is a cross-sectional view of the developing device 3 according to the present invention. When the main body of the copying apparatus is set, the sleeve cover 2 is opened and set to the dotted line position. The developing sleeve 1 has a magnet 1a inside, and a non-magnetic cylinder 1b rotating around the magnet 1a in the same direction as the photoreceptor transfers the toner on the cylinder surface to the photoreceptor to perform so-called jumping development. When the amount of toner in the developing section B becomes low, the toner sensor S becomes exposed, and a motor V rotates the replenishment roller 6 in response to a signal indicating that the toner is running out, causing the toner to fall to the hopper section B. This replenishment is carried out using a magnetic replenishment roller 6 on the back plate 7.
The toner is scraped out from the gap between the toner and the front plate 8, but other methods are also possible.Motor M rotates the upper stirring shaft and 9, and 6. This rotation causes the toner to be brought closer to the supply roller by the stirring rod 10.

The lower stirring shaft rotates at a slow speed in synchronization with the rotation of the 3-piece sleeve 1,
The stirring rod 4 brings the toner closer to the sleeve, and the wiper 5 wipes the surface of the senna S. This is due to toner sticking to the surface of the senna due to high humidity, high temperature, etc.
This is because it may be difficult to wrap around and may cause it to stick.

FIG. 2 is a block diagram showing a configuration example of a toner replenishment device according to the present invention, in which the developing device B has a toner sensor S1 and a toner replenishment motor M, and the output of the toner sensor and the 0N10 FF control of the toner replenishment motor V are connected to each other. /Troll input is routed to controller C. Control device C is a controller that controls the copying operation of a copying machine or a laser beam printer, and although not shown in the figure, it receives the 0N10FF of the drive unit motor, transfer paper conveyance control, and sensor signals to check whether the operation is appropriate. It also controls the high-voltage power supply for the electrostatic transfer process, and controls the timing for the paper feed clutch and document scanning.
It usually consists of a microcomputer consisting of ROM, RAM 110, timer, CPU, etc.

The data programmed into this ROM
The replenishment judgment according to the present invention also relates to this setting.

The out-of-toner warning lamp notifies the user of the machine when the microcomputer determines that there is no toner, prompts the user to replenish toner, and prevents blank copies from being made when there is no toner. It shows.

This will be explained in more detail using the timing chart in FIG. 3(T)-(■).

(I) When copying one sheet and toner is present When the copying operation is started, the photoreceptor sleeve 1 and wiper 5 shown in FIG. 1 begin to rotate.

The wiper 5 is rotating about the shaft 3 in the direction of the arrow shown while scraping the surface of the sensor S. (1)
The output of the toner detection signal shown in (a) is valid only during the copying operation period shown in (a).

When the wiper 5 stirs the toner T1 on the surface of the sensor S, the sensor output shows a changing waveform as shown in (b). This is because the toner is removed by the wiper and temporarily disappears from the sensor surface. At this time, since the out-of-toner signal does not continue for a certain period of time, the control device determines that there is no toner out, and (C)! As shown in the IC, the replenishment motor does not rotate and the toner replenishment operation does not occur.

This judgment time is determined based on the time required for one rotation of the wiper. In other words, if there is toner, even if the toner temporarily disappears from the sensor surface, it will return to its original state within one rotation of the wiper, so the time required for one rotation should be set to the minimum, or a little longer than this.

(■) After toner was detected at one time when copying one sheet, when the copying operation was started when there was a toner, the toner-less state indicated by IC (1) IK immediately occurred, and this state continued for 11 hours. This 11 hours corresponds to a somewhat longer time than the one rotation time of the wiper mentioned in (I)K above. Since there is still no toner even after this period of time has elapsed, it is indicated that there is no toner temporarily due to the moving operation of the wiper, so in order to drop the toner from the upper hopper, the control device sends an instruction to rotate the replenishment motor (as shown in cl K). put out.

Since the toner falls into the lower hopper from K and some toner is present on a portion of the toner sensor, the toner detection signal shows the normal 1H'' level and the copying operation is completed.

(Ill When there is no toner immediately after the toner is detected immediately before the copy is completed. In this case, the detection is the same as the state described in (II) K above, but even if the replenishment motor starts operation, there is no toner. At this time, during operation time 1 of the replenishment motor, even if the copying operation is completed, the drive motor of the main body continues to rotate so that the wiper operates.At this time, the electrostatic transfer process of the high voltage section etc. It is not necessary to operate the replenishment motor.It is best to determine the time t by the operation time of the replenishment motor from the level of a part of the second hopper that detects the lack of toner until it becomes full. Even if the sensor's signal detection circuit itself is destroyed, it will stop within the time it takes to reach the groove bar, which prevents the accident of overfilling a part of the hopper with toner and damaging the developing device. Also, the reason why the copying operation is maintained for 11 hours at 1t when no toner is detected even though the electrostatic transfer process is finished at 7'tK is to enable the detection operation to be performed under the same conditions. For example, in the middle (
11. As in (II), it is also possible to finish the copying operation in the time required for one copy, add the previous copying time to the next copying time, and stop the copying operation at the integrated time t7. However, with modern copying machines, it is possible that the colorization of toner may become too powerful and cause the machine to change to a color developer after the copying operation is complete, so the data from the previous copy is no longer valid. Therefore, it is better to use K as in this operation. Then, after the time period 7 has elapsed, the copying operation is stopped, and the toner out indicator lamp is turned on as shown in (d) to prevent the machine from operating again in the toner out state.

(■ Multi-copy temporary button When there is no toner after toner is detected. In this case, when making many copies in succession, this is to prevent the operation from being forced to stop midway due to no toner. This is a case where the amount of toner in the copy is lower than the level at which the toner sensor detects the presence of a toner sensor, and the number of sheets that do not become blank is specified as multiple copies.This allows the copying operation to continue for the specified number of sheets. This makes it easy for the user to make a break because the user is prompted to replenish the toner after the work is completed.

(■ The number of copies exceeds the limited number of copies, and in the middle of the process, it is detected that there is no toner, and at this time, the number of copies exceeds the capacity of the second hopper when the number of copies exceeds the capacity of the second hopper. In this case, the toner will completely run out during this process, so
The copying operation is always forcibly stopped at the limited number of copies determined by this capacity to prevent blank copying from being performed.

At the same time, a toner out warning is displayed to prompt the user to replenish toner.

(Effects of the Invention) As described above, according to the present invention, in order to maintain a constant image density, the wiper operates while keeping the toner capacity in the developing device constant and reliably refreshing the surface of the toner sensor. It is possible to eliminate malfunction detection caused by

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a developing device according to the present invention, and FIG.
3 is a block diagram showing a configuration example of a toner replenishing device according to the present invention, and FIGS. 3(1) to 3(V) are timing charts for explaining the present invention. Sleeve B...Developer D...Photoconductor S...Represents the fist toner sensor. (C)'a compression motor 4 L 3 diagram (IL) 00 ↑-Mai Lno ii-

Claims (1)

[Claims] The image forming apparatus has a remaining amount of toner detection means disposed in a developing device, a control device for performing sequence operations of the image forming apparatus, and a means for warning of an out-of-toner state, and the control device detects the remaining amount of toner. When controlling the image forming operation and warning of the out-of-toner condition based on the output of the means, the amount of remaining toner is detected while the developer carrier is rotating during the image-forming operation, and the amount of remaining toner is detected when the toner is out for a certain period of time. If the replenishment operation is performed and the toner does not become available within a certain period of time after the start of the replenishment operation, a toner out warning will be displayed when the image forming operation is stopped or after the image forming operation is forcibly stopped after counting a certain number of sheets. Even if the image forming operation can be completed within a certain period of time after starting the replenishment operation, the image forming operation will continue until there is toner, and if there is toner, it will stop and the toner will run out. A toner replenishing device characterized in that if there is no toner, a warning message indicating that there is no toner is displayed.