JPS62291680A - Toner emptiness detector - Google Patents

Abstract

PURPOSE:To accurately inform a toner feeding time by providing the titled detector with a counting mechanism and a control mechanism for detecting the empty state of a toner storing part when the number of times of toner feeding reaches the previously stored number of times of empty. CONSTITUTION:When the quantity of toner fed by a toner cartridge 61 is set to 60g, the quantity of toner fed by one feeding operation is 120mg and toner in the toner cartridge 61 is consumed by 500 times of feeding operation. Therefore, when the number N of counts is >=500, a LED 103 for empty toner display on an operation panel 101 is lighted to inform the replacement of the toner cartridge 61. After extinguishing all LEDs 1-5, the operation is returned. When the number N of counts is <500, the operation is continued without lighting the LED 103. Consequently, the toner consumption and its residue can be accurately informed in both the cases of character originals and solid black copies.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a toner empty detection device for detecting an empty state of toner in a toner storage section of a copying machine or the like.

(Prior Art) Generally, in a device such as a copying machine that uses toner to form an image, a toner storage tank is attached to the developing device in order to replenish the amount of toner commensurate with the amount consumed by development. Toner is replenished from the toner storage tank according to the situation.

Therefore, in this type of toner replenishment mechanism, a toner empty detection device is required because it is necessary to detect the toner empty state of the toner storage tank and maintain a state in which l.toner can be replenished at all times.

However, most of the conventional toner empty detection devices directly detect the amount of remaining toner, and their mechanisms are complicated and their accuracy is inaccurate.

For this reason, various types of toner empty detection devices have been proposed in recent years, and one of them is to store in advance the amount of toner consumption that is expected to be consumed depending on the paper size, Detect the paper size and number of sheets used for each size, multiply the number of sheets used for each size paper by the toner consumption m, add these to calculate the total toner consumption, and calculate the remaining amount of toner based on this calculated value. A method for detecting is disclosed in Japanese Patent Laid-Open No. 182480/1983.

(Problem to be solved by the invention) However, the amount of toner consumed depends on the object to be copied,
That is, it differs greatly depending on whether the original to be copied is a text original or one with solid black parts.

Therefore, the remaining amount of toner calculated by the toner empty detection device may differ from the actual remaining amount, and toner empty may be displayed even though there is sufficient toner remaining, or conversely, the toner empty state may occur. However, there is a problem in that the toner replenishment time cannot be accurately notified because the toner replenishment indication is not displayed even though the toner is refilled.

(Means for Solving the Problems) The present invention has been made to solve the problems previously described.
- In a toner replenishment mechanism that replenishes a fixed amount of toner each time the toner is replenished, there is a counting mechanism that counts the number of times the toner is replenished, and when the toner replenishment number reaches a predetermined empty number that is stored in advance, the toner is refilled. A control mechanism for detecting the empty state is provided.

(Example) Hereinafter, the present invention will be described with reference to the accompanying drawings which are one example.

Overall configuration FIG. 1 shows an image forming unit equipped with a developing device (20), which is one embodiment.

This image forming unit includes a photoreceptor drum (10), a developing device (20) and a cleaning device (50) disposed on both sides of the photoreceptor drum (lO), and a cleaning device (50).
0), that is, on the opposite side of the photoreceptor drum (10);
) and a charger (not shown) placed on the road.

Further, each of these members is integrated into a unit by a frame (1) (the rear side is not shown), and a developing device (20 ) is provided with a conveyance means (45).

Description of each part 1. Developing device (20) As shown in FIGS. 2 and 3, the developing device (20) includes a developing sleeve (21) facing the surface of the photoreceptor drum (10).
This is a well-known magnetic brush type rake with a built-in magnetic roller (22).

At the back of the developing sleeve (21) is a screw (24),
Developer conveyance paths (23) and (25) are provided in parallel with the developing sleeve (21), and the developer conveyance paths (23) and (25) are partitioned by a partition plate portion (27). The two ends (27a) and (27b) communicate with each other.

The screws (24) and (26) are connected to drive gears (16) and (17) provided at the end of each support shaft, respectively, through the drive gear (15) provided at the end of the support shaft of the developing sleeve (21).
) and (b). Further, the drive gear (15) meshes with a drive gear (see Fig. IIX) provided at the end of the support shaft of the photoreceptor drum (10).
1) is connected to a main motor (not shown).

Note that the developing agent used is a mixture consisting of a magnetic carrier and a non-magnetic toner.

With the above configuration, the developing device moves the conveyance path (23) along the arrow (A) based on the rotation of the screw (24) in the direction of the arrow (A).
) direction while being agitated and mixed, wraps around from the end (27a) into the conveying path (25), and is conveyed while being agitated and mixed in the direction of arrow (B) based on the rotation of the screw (26) in the direction of arrow (b). from the end (27b) to the conveyance path (23
).

That is, the developer is circulated and conveyed through the conveyance paths (23) and (25), and the toner is sufficiently charged by friction with the carrier during stirring and mixing in the conveyance path (23), and the toner is charged by the arrow in the conveyance path (25). It is magnetically attracted to the outer peripheral surface of the developing sleeve (21) rotating in the direction (C). The developer supplied to the development sleeve (21) is conveyed in the direction of arrow (c) while the height of the developer is regulated by the height regulation plate (28), and rotates in the direction of arrow (d) in the development area (R). The electrostatic latent image formed on the surface of the photoreceptor drum (10) is developed.

Note that a magnetic toner concentration sensor (29) is installed at the bottom of the developer transport path (23) so as not to interfere with the mixing and transport of Ml of the developer.

This sensor (29) detects the toner concentration in the developer based on the change in the inductance of the coil as a change in the magnetic permeability of the developer. The output voltage characteristics of the toner concentration sensor (29) used in this embodiment are as shown in the graph of FIG. 6, and are inversely proportional to the toner concentration. In addition, in this example, the adjustment value of the toner density is 6.
, 5 wt%, and the corresponding output voltage is 2.5■. Therefore, when the output voltage of the sensor (29) rises above 2.5V, the toner replenishing device (30), which will be described below, is activated.

11. Toner replenishment device (30) As shown in FIG. 1, the toner replenishment device (30) includes a toner box (31
), attach the screw (32) and rotating blade (35),
A toner cartridge (61) is removably attached to the upper cartridge accommodating portion (60).

The toner cartridge (61), as shown in FIG.
It consists of a cylindrical main body (62) and caps (64) and (67) attached to both ends of the main body, and GOg toner can be stored inside. An opening (6-3) is formed in the main body (62) along the axial direction, and a groove tape (68) is attached to the outside of the opening (63) so as to close the opening. , one cap (64)
A magnet (66) facing the outer peripheral surface is attached to the handle, and a handle (65) is formed therein.

On the other hand, as shown in FIG. 5, a self-holding reed switch (
69) is fixedly installed, and is turned on when the magnet (66) approaches.

When the reed switch (69) is turned on, the on signal is input to the microcomputer (MC) shown in Fig. 7, and the counter (100) built therein is reset to "0". .

Note that, when the reed switch (69) outputs the ON signal to the microcomputer (MC), immediately after that, a signal is input from the microcomputer (MC) and the reed switch (69) is reset.

Therefore, the toner cartridge (6
1) is inserted into the cartridge accommodating part (60) from the entrance side (not shown) of the cartridge accommodating part (60) with the opening (63) facing upward while peeling off the roll tape (68). When the magnet (66) approaches the reed switch (69) and is turned on, the signal is input to the microcomputer (MC). Next, the toner cartridge (61) is attached to the handle (65).
) and rotated 1800 times to enable toner to be supplied to the toner box (31).

Note that when replacing the toner cartridge (61), rotate the toner cartridge (61) 180 degrees and remove the opening (
63) and pull it out.

A screw (32) installed at the bottom of the toner box (31) is connected via a clutch (3=1) and can be driven to rotate in the direction of arrow (e) by an f-2 drive gear (33). This rotation moves the toner toward the hand side [arrow (E)
) direction].

The rotating blade (35) has support shafts (35a) and (35b) at both ends.
The drive gear (36) fixed to the support shaft (35b) (meshing with the drive gear (33)) can be rotatably driven in the direction of the arrow (r), and this rotation The toner is conveyed to the upper part of the screw (32).

The drive gear (33) is connected to the drive gear (1) of the photoreceptor drum (10) via an idle gear (not shown) and a drive gear (54) of the conveying coil (53), which will be described below.
1) and is driven to rotate in the direction of arrow (e). The clutch (34) is always off, and is turned on for a certain period of time when the toner concentration sensor (29) detects that the toner concentration in the developer is lower than a set value (6.5 wt%). , the screw (32) is driven to rotate to accurately take in a certain amount of toner in the toner cartridge (61).

Toner conveying means (45) The toner conveying means (45) is provided with a conveying coil (47) in the conveying pipe (16), so that the toner conveying means (45) moves from the toner replenishing device (30) to the phenomenon device (20). It is installed.

One end of the conveyance pipe (46) is connected to the front of the toner box (31) so as to surround the protruding portion of the screw (32), and the other end has an opening (46a) connected to the developer conveyance path (20) of the developing device (20). 23) is installed so as to be located above the opening (23a) at one end (see FIG. 3).

Toner is transported to one end of the transport pipe (46) by rotation of the screw (32).

The tip portion (32a) of the blade plate of the screw (32) has a substantially V-shape that expands in the rotational direction [direction of arrow (e)].
This portion makes it easy for the toner to fall into the conveying pipe (46).

On the other hand, the conveyance coil (47) is installed over the entire length of the conveyance pipe (46), and a helical gear (48) is provided at the other end.
This rotation transports toner in the direction of arrow (G) and supplies it to the end of the developer transport path (23) through the opening (46a).

The helical gear (48) is a gear (18) fixed to the shaft end of the screw (24) provided in the developer transport path (23).
) through an idle gear and a helical gear (not shown).

iv. Cleaning device The cleaning device (50) uses a blade (51) to scrape off residual toner on the photoreceptor drum (lO), and has a conveyance path (52) equipped with a conveyance coil (53).
The front end of is connected to the middle of the conveying pipe (46).

The conveyor coil (53) is connected to the drive gear (54) by the arrow (h).
The toner scraped onto the conveyance path (52) by this rotation is conveyed in the direction of the arrow (■4), that is, sent into the conveyance pipe (46).

The collected toner thus sent to the conveying pipe (46) is conveyed to the developing device (20) by the conveying means (45) together with the toner replenished from the toner replenishing device (30).

Toner replenishment operation In the above configuration, toner replenishment is performed when the toner concentration sensor (29) detects that the toner concentration in the developer is lower than the set value (6.5 wt%). 34) for a certain period of time (5 seconds in this embodiment) and rotates the screw (32). In this embodiment, the rotation speed of the screw (32) is 30 rpm, and 1206 toner particles are accurately fed into the conveying pipe (46) in 5 seconds of rotation.

The conveyance coil (47) is driven to rotate while the main motor is turned on, and sequentially conveys the toner fed into the conveyance pipe (46) to the end of the developer conveyance path (23).

By the way, for a certain period of time after the stirring and mixing operation of the developer is started until the stirring and mixing state of the developer is stabilized, toner replenishment is carried out in order to maintain a constant toner concentration in the developer in the developing device (20). Action to control (hereinafter referred to as A 'I' D
(referred to as C control) to prevent the toner density from increasing more than necessary.

Specifically, in this embodiment, the main motor is driven to drive the screws (24) and (2) in the developing device (20).
6) Execution of ATDC control is prohibited for 5 seconds after the motor starts rotating.

The timing at which the main motor is driven is when the main switch is turned on and the power is turned on, or when the print switch is turned on after the copying machine is in a standby state.

The copying machine is set to the standby state (main switch on, main morph off) if the print switch is not turned on even after 12 seconds have passed after the main switch has been turned on, or if 10 seconds have passed after copying has elapsed. This is the case when the print switch is not turned on even after

Control Figure 7 is a block diagram of the control circuit, which is mainly composed of a microcomputer (MC), which controls the signals of the main switch, print switch, and detection signal of the toner density sensor (29). The main motor, toner replenishment screw, Yu (3)
2) ON/OFF signals to the clutches (3, 1) are output.

Also, the microcomputer (~IC,) has a timer (1
), (2), and (3). Timer (1) is an auto-shut timer after the main switch is turned on, timer (2) is a prohibition timer that sets the time to inhibit ATDC control, and timer (3) is an auto-shut timer after the print switch is turned on. It is.

Furthermore, the microcomputer (MC) is connected to the reed switch (69) of the cartridge accommodating section (60), and resets the counter (100) to "0" when the reed switch (69) is turned on. Start.

The counter (100) is a microcomputer (MC)
is the clutch (34) of the toner supply screw (32)
When the on signal is output to , "B" is added.

In a microcomputer (MC), a counter (100
), the remaining amount of toner is detected according to the flowchart shown in FIG. 11, and the result is displayed on the display panel (101) shown in FIG.

The display panel (101) has two digit 7seg LEDs (1
02) and a red toner empty indicator LED (103).
) and a yellow LED l,~,5 are provided.

The 7seg LED (102) displays the number of copies, and the toner empty display LED (l O3) and LED 1
.

. . . , 5 are for displaying toner empty and toner remaining amount.

FIG. 9 shows the control when the main switch is turned on. When the main switch is turned on, the step (S
IO) initializes the microcomputer and performs initial settings to put each device into the initial mode.

Next, at Sit, the auto-shut timer (1) is set to 12 seconds, at S12, the prohibition timer (2) is set to 5 seconds, and at S+3, the main motor is turned on. This completes the preliminary rotation of the photoreceptor drum (IO) and the development device (20
Preliminary rotation of the screws (24) and (26) in ) is performed.

Subsequently, it is determined in S14 whether or not the prohibition timer (2) has expired, and if the prohibition timer (2) has expired (if 5 seconds have elapsed since the main morph was turned on), ATDC control is executed in Si5. In other words, ATDC control is prohibited until timer (2) expires.

Furthermore, in 916, it is determined whether or not the timer (1') has expired. If the timer (1') has not expired, the process returns to S14, and if it has finished, S
At step 17, the main motor is turned off and set to standby mode.

FIG. 1O shows the control when the print switch is turned on. When the print switch is turned on, first, S20
Set the prohibition timer (2) to 5 seconds with S2+
The main motor is turned on in step S22, and the copying operation is started in step S22. Then, it is determined in S23 whether or not the copying operation has been completed, and if it has not been completed, it is determined in S24 whether or not the prohibition timer (2) has expired, and if it has not been completed, the process returns to S23; ATDC control is executed in S25.

When the copying operation is completed, the auto-shut timer (3) is set to 10 seconds in S26, and this timer (3) is set in S27.
It is determined whether the
Executes TDC control. When timer (3) ends, S2
At step 9, turn off the main motor and set it to standby mode.

The operations of ATDC, remaining toner amount display, and toner empty detection control will be described below.

FIG. 11 is a flowchart showing control of ATDC, remaining toner amount detection, and toner empty detection.

First, from 5IOI to 103 is the reed switch (69)
This is the process of determining whether or not the switch is turned on. That is,
The process of detecting when a new toner cartridge (61) is installed and resetting the counter (100) is shown.

Therefore, when the toner cartridge (6) is newly installed, the reed switch (69) is turned on and the 5101 to 1
02, the count number (N) of the counter (+00) is reset to "0", and immediately thereafter, in 5103, the reed switch (69) is reset to the OFF state.

Incidentally, if the toner cartridge (61) is installed in a normal usage state, the reed switch (69) is in the OFF state, and the process suddenly advances from 1 lot to 5104. In addition, the toner cartridge (61) is replaced while the power is off, but the next time the power is turned on, the dead switch (69) is in the off state, so the change is suddenly made from lot 5 to lot 5104. .

At S+04, it is determined whether or not the toner concentration sensor (29) is on, that is, the toner concentration in the developer is at the set value (
If it is lower than 6.5wL%), operate the toner replenishment screw (32) and set the count number (N
) to the toner replenishment clutch (3).
3) Turn on for 5 seconds to replenish toner.

Subsequently, in 5107, it is determined whether the count (N) is 500 or more, and it is determined whether the toner in the toner cartridge (61) is in an empty state.

That is, the amount of toner replenished by the toner cartridge (61) is 60 g, and the amount of toner replenished by one replenishment operation is 120 mg, so the toner in the toner cartridge (61) is consumed by 500 replenishment operations. be done. Therefore, if the count number (N) is 500 or more, the toner empty display LED (103) on the operation panel (IO+) is turned on in step 8108 to notify that the toner cartridge (61) needs to be replaced.

Then, all LEDI, . . . , 5 are turned off and the process returns.

If the count number (N) is less than 500, the LED (103
) without lighting it and moves to the next step 8109.

For 5109 and 110, the count number (N) is O≦N<10
Determine whether or not it is within the range of 0, "YES", that is,
If the toner level is almost full, the LED I...
..., all 5 lights up.

Next, in 5lll and 5112, it is determined whether the count number (N) is within the range of h month 00≦N<200, and “Y
ES", lights up LEDI,..., 4, and
Turn off 5.

Thereafter, in the same way, the count number (N) is determined from 5113 to Sl 18, and the LED, ・
..., 5 turns on and off.

In this way, as the remaining amount of toner decreases, the LED
, . . , 5 will be lit, and by looking at this, you can predict when it is time to replace the toner cartridge (6).

In addition to the method of measuring the magnetic permeability of the developer, the toner concentration can also be detected by a method of measuring the electrical resistance of the developer. Furthermore, it goes without saying that the ATDC control prohibition time differs depending on the developing device.

Furthermore, in the present invention, the toner concentration detection operation is prohibited for a certain period of time, but the toner replenishment operation itself can be performed. That is, the toner concentration detection result before the copying machine enters the standby state may be stored in memory, and the toner replenishment operation may be performed in accordance with the previous detection result immediately after the developer stirring and mixing operation is started.

(Effects of the Invention) As is clear from the above description, in an apparatus having a mechanism for replenishing a fixed amount of toner, the amount of consumed toner and the amount of remaining toner are measured by counting the number of toner replenishing operations.

Therefore, it is possible to accurately notify the toner consumption amount and remaining amount regardless of whether the toner is a text original or a solid black copy.

Also special? A U1 configuration is not required, and there are no problems in terms of ease of assembly or cost.

[Brief explanation of drawings]

The drawings show an embodiment of the electrostatic latent image developing device according to the present invention, and FIG. 1 is a partially cutaway perspective view of an image forming unit equipped with this developing device, and FIG. 2 is a vertical cross-section of the developing device. Figure, 3rd
The figure is a horizontal sectional view of the developing device, Figures 4 and 5 are perspective views and front views of the toner cartridge, Figure 6 is a graph showing the output voltage characteristics of the toner density sensor, and Figure 7 is a block diagram of the control circuit. , FIG. 8 is a toner remaining amount display section of the operation panel, and FIGS. 9 to 11 are flowcharts showing the control procedure. (lO)...Photosensitive drum, (20)...Drive device, (21)...Phenomenon sleeve, (23), (25).
Developer conveyance path, (24), (26)...screw,
(2)・Toner concentration sensor, (30)...Toner replenishment device, (32)・Toner replenishment screw, (3,1
)...Crabchi, (61)...Toner cartridge,
(69)...Reed switch, (100)--Counter.

Claims (1)

[Claims] (1) In a device that employs a toner replenishment mechanism that replenishes a certain amount of toner in one replenishment operation, there is a counter mechanism that counts the number of toner replenishment times, and a toner replenishment mechanism that counts the number of toner replenishment times and a toner replenishment mechanism that A toner empty detection device comprising: a control mechanism for detecting an empty state of a storage section.