JPH02143270A - Developing device - Google Patents

Abstract

PURPOSE:To surely confirm the toner replenishing operations to a developing device by discriminating whether or not the developing operations of the device are to be restored based on the toner concentration after a toner replenishing mechanism is driven for a prescribed period of time. CONSTITUTION:This developing device does not shift as in the conventional means to developing operations indiscriminately when its cover body 9 is closed, but shifts to the developing operations based on the state of the toner concentration detected by a concentration detection circuit 11 after a toner replenishing mechanism is driven for a prescribed period of time by means of a timer 17. Therefore, when a toner empty state occurs due to various irregular troubles taking place during the period until the cover body 9 is closed again after it is opened, the state is surely detected and execution of the developing operations with an insufficient quantity of toner after the cover body 9 is closed can be prevented surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device incorporated into an image forming machine such as a printer or a copying machine, and particularly to a developing device using a two-component developer consisting of a carrier and a toner. Regarding.

"Prior Art" A developing device using a two-component developer consisting of, for example, a carrier and a toner has been known, and in this type of developing device, toner is supplied to a developing container containing the developer at a predetermined mixing ratio. The toner containers are connected via a mechanism, and a toner concentration sensor is disposed inside the developer container to measure the mixing ratio of the toner and carrier that occurs each time the toner is consumed from the developer container by a predetermined electrophotographic development operation. The change is detected by a toner 6 degree sensor, and the toner replenishing mechanism is driven and controlled based on the detection signal to sequentially supply toner from the toner container into the developer container.

In such an apparatus, when the toner in the toner container becomes empty (hereinafter referred to as "toner empty"), the image forming operation including the developing operation is stopped based on a detection signal from the toner sensor, and the image forming operation is stopped to produce an image with insufficient density. After preventing deterioration and replenishing the toner container with toner by opening the door, lid, etc. that hide the toner container (hereinafter referred to as a cover), press the reset switch to return to the stopped state. However, in such a device, a reset switch must be operated before toner replenishment, and the replenishment operation is troublesome.

For this reason, in an electrophotographic apparatus having a safety switch provided on the cover body side that is opened when performing the toner replenishment operation, and a storage means for storing the toner empty state,
A device has been proposed in which the storage means is reset based on a signal from the safety switch that is oscillated in conjunction with the cover body closing operation. (Jikko 62-4
No. 3311) "Problem to be Solved by the Invention" However, the reset operation of the - function (toner empty state confirmation function) can also be used as a switch operation for performing another function (cover closure confirmation function). This can easily cause malfunctions, such as when the cover body is simply reclosed without toner replenishment (this often happens due to door chattering, etc.), or due to troubles such as jamming. If the toner becomes empty due to inertia of the toner replenishment mechanism after opening the cover body, and the cover body is reclosed without noticing the empty state,
In either case, since the storage means is reset, the process automatically shifts to image forming operation, resulting in image defects.

In addition, if toner is accidentally spilled from the toner container when the developing device is removed from the image forming machine for maintenance due to a problem other than empty toner, in any of the above conventional techniques, the toner in the toner container is empty. It is impossible to judge whether or not this state has occurred, and in such a case, if the developing device is reinstalled into the image forming machine and the image forming operation is started, a defective image will naturally occur.

In view of the drawbacks of the prior art, it is an object of the present invention to provide a developing device that can reliably confirm toner replenishment operations while avoiding the complexity of toner replenishment operations and preventing malfunctions. do.

Another object of the present invention is to reliably detect even when the toner empty state occurs due to irregular troubles after opening the cover body, and to detect the toner empty state after the cover body is closed. It is an object of the present invention to provide a developing device that can reliably prevent a shift in developing operation.

"Means for Solving the Problems" In order to achieve the above technical problems, the present invention proposes a developing device having the following constituent elements.

■ It has a toner replenishment mechanism that sequentially replenishes the toner stored in the toner container to the developing container based on the signal from the toner concentration sensor. ■ It has a cover body that is opened and closed to replenish toner into the toner container. (1) having a timer means for driving the toner replenishing mechanism for a predetermined time in conjunction with the closing operation of the cover body; (2) based on the toner concentration state after the toner replenishing mechanism is driven for a predetermined time by the tire means; Note that the above technical means is based on the assumption that the four prefectures have a means for stopping the developing operation before the cover body closes, as is clear from the description of configuration requirement (2). However, such stopping means may be, for example, a control means that stops the developing operation when the amount of toner stored in the toner container drops below a predetermined amount. The configuration is “
The control means is reset based on the toner concentration state after driving the toner supply mechanism for a predetermined period of time.

If the stopping means is a forced shutting off means that stops the developing operation when the cover body is opened, the specific configuration of the component (2) is [Toner concentration after driving the toner supply mechanism for a predetermined time] Point J is where the forced cutoff means is reset based on the state.

"Operation" This technical means is such that, for example, when an empty toner container is replenished with toner and toner is present in the toner container before the cover body closing operation, the toner is refilled in conjunction with the cover body closing operation. By driving the replenishment mechanism for a predetermined period of time, the toner concentration state in the developer container increases, and by appropriately setting the predetermined period of time, the toner concentration can always be within the specified concentration range. , the development recovery operation is performed after determining the time-series change in the toner density and whether or not the toner density has reached a specified density.

Therefore, there is no need to provide an independent reset switch as in the prior art, and the present invention does not automatically perform the developing operation by simply closing the cover, but rather the toner is present in the toner container. Since the toner replenishment operation can be automatically shifted to the developing operation only when the toner is in use, the toner replenishment operation is simplified and no malfunction occurs.

Further, the present invention does not aimlessly shift to the developing operation by opening the cover body as in the prior art, but starts the developing operation based on the toner density state after driving the toner replenishing mechanism for a predetermined period of time. Because it migrates, even if the toner becomes empty due to the various irregular troubles mentioned above that occur after the cover is opened and before it is reclosed, this can be reliably detected and the cover can be opened. It is possible to reliably prevent the development operation from shifting when there is insufficient toner.

Further, according to the present invention, not only is there no need to provide an independent reset switch, but also existing circuits and components can be used except for the timer means, which not only simplifies the mechanism and configuration but also reduces the number of parts. Connect.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. It's nothing more than that.

FIG. 1 shows the main structure of a laser printer incorporating a developing device according to an embodiment of the present invention.To briefly explain the mechanical structure, 1 shows a carrier and toner (hereinafter referred to as developer) in a predetermined manner. In a developing container stored in a density ratio, a developing roller 4 containing a mag roll (not shown) is pivotally supported on the opening side facing the photoreceptor drum 3, and a partition plate 5 is installed above the developing container l. The toner container 2 is connected via the toner container 2.

The toner container 2 is configured such that its upper surface side opens in conjunction with the opening operation of a cover body 8 forming a part of the printer frame 23, so that toner can be replenished.

A slit opening 6a is formed at the bottom of a tapered guide recess 6 formed at an arbitrary location on the partition plate 5 below the toner container 2, and a toner replenishing roller 7 covered with a sponge is inserted into the opening 6a. It is rotatably attached to the roller 7,
A toner supplement motor, whose rotation is controlled based on a signal from a concentration detection circuit, is connected via a drive circuit 20.

On the other hand, inside the developer container 1, an agitation member 8 which is configured to be rotatable in synchronization with the developer roller 4 and following the rotation of the toner replenishment candy roller 7 is installed approximately in the center of the developer container l. The toner supplied in the container l can be uniformly stirred together with the developer in the container l, and
A toner concentration sensor l is installed on the bottom side of the container 1 below the stirring member 8.
The toner density sensor lO is configured to output a detection signal to the density detection circuit 11 side.

Now, a safety switch 12 is attached to the printer frame 23 on the side facing the cover body 9, and when the cover body 9 is opened, the fuser, charger, laser ( The high-voltage power source 14 (both not shown) is forcibly cut off, and the energized state of the high-voltage power source 14 can be restored by closing the cover body 9.

Next, to explain the circuit configuration of the parts not explained in the explanation of the mechanical configuration, 1 is an online key 15 for transmitting image signals from the computer side to the printer side, and the cover body 9 is closed. When the online key 15 is pressed, the key human power judgment circuit +e, ? A timer 17 is started via the degree detection circuit 11, and the toner replenishing roller 7 is configured to be able to be driven for a predetermined period of time.

Note that the timer 17 starts even when the toner concentration in the developer container 1 decreases, and for example, when the toner concentration sensor 1
When the toner concentration falls below the specified amount based on the signal from 0, the timer 17 is started and the toner replenishment roller 7 is driven for a predetermined period of time to replenish toner. In some cases, the amount returns to the specified amount, but if there is no toner in the toner container 2, the amount does not return to the specified amount, so it can be determined that there is no toner. Therefore, in this embodiment, there is no need to provide a separate toner sensor.

Next, the series of operations from the toner empty state to the recovery operation in this embodiment will be explained step by step based on the flowchart in FIG. When the toner in the toner container 2 runs out and the concentration detection circuit 11 determines that there is no toner (STEP 2), the detection circuit 1
1, a two-button signal is set in the toner empty register 18 (STEP 3), and the high-voltage power source 14 for the fuser, charger, laser, etc. of the laser printer including the developing device is forcibly cut off via the opening/closing control circuit 13. With L.E.
DI! Revise 3 and display Tona Empty.
(STEP and the user opens the cover body 9 by lighting the LEDI9 (STEP 5)) After replenishing the toner container 2, the user closes the cover body 9 (STEP 8)
, and press online key 15 (STEP 7)
) As a result, the toner replenishment motor old is turned on and at the same time the timer 17 is started to drive the toner replenishment roller 7 for a predetermined period of time. (STEP 8) Then, when the toner concentration returns to the specified amount during the driving (STEP 9), the toner replenishment motor is turned OFF and the replenishment operation is stopped (STEP 9).
0),) Reset the navigation register 18 and LE
Turn off 018 (STEPI+) and return to STEPI.

In addition, if the toner concentration does not return to the specified amount even after a predetermined period of time has passed due to reasons such as forgetting to replenish toner (STEPI 2), turn off the old toner replenishment motor (STEPI 3).
), return to 5TEP2.

Repeat this below.

"Effects of the Invention" As described above, according to the present invention, there is no need to provide an independent reset switch as in the prior art, and the developing operation is automatically performed by 119, which performs the closing operation of the cover body. 11), which automatically shifts to the developing operation only when there is toner in the toner container, simplifies the toner replenishment operation and prevents malfunctions. Even if the toner becomes empty due to occasional troubles, it can be reliably detected and the system can reliably prevent the development operation from shifting when the toner is insufficient after the cover is closed. have

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the main structure of a laser printer incorporating a developing device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing its operating procedure.

Claims (1)

[Scope of Claims] 1) A toner replenishment mechanism that sequentially replenishes the toner stored in the toner container to the developer container side based on a signal from a toner concentration sensor, and a toner replenishment mechanism that opens and closes to replenish the toner into the toner container. and a timer means for driving the toner replenishing mechanism for a predetermined period of time in conjunction with the closing operation of the cover member, the toner concentration state after the timer means drives the toner replenishing mechanism for a predetermined period of time. 2) A developing device characterized by determining whether or not the developing operation is to be resumed based on 2) a control means for stopping the developing operation when the amount of toner stored in the toner container drops below a predetermined amount; 3) The developing device according to claim 1), wherein the control means is reset based on the toner concentration state after the replenishment mechanism is driven for a predetermined time. 3) The developing operation is stopped when the cover body is opened. The developing device according to claim 1, further comprising a forced shut-off means for resetting the forced shut-off means based on a toner concentration state after driving the toner supply mechanism for a predetermined period of time.