JPS63205679A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent 'fogging' by driving agitating means for prescribed time to agitate two-component developers after stop of a replenishing operation when the stop of the non-stationary replenishment operation is commanded. CONSTITUTION:This image forming device has a developing device 4 for visualizing an electrostatic latent image to a visible image by a toner, the agitating means 41, 42 for agitating the two-component developers in the developing device, toner replenishing means 43, 44 for replenishing the toners into the developing device, a replenishment input means 91 for commanding the non-stationary replenishment operation by the toner replenishing means, a stop input means 93 for commanding the stop of the non-stationary replenishment operation, and a control means 2 for agitating the two-component developers by driving the agitating means for the prescribed time after the stop of the replenishment operation when the stop of the non-stationary replenishment operation is commanded. The toners and carriers in the developing are, therefore, agitated for the prescribed time when the non-stationary toner replenishment is commanded and the interruption of the toner replenishment is thereafter commanded. The toners and carriers are thereby sufficiently commanded. The toners and carriers are thereby sufficiently triboelectrostatically charged and the 'fogging' is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image forming device with improved toner replenishment method. By improving the I-electric current, 11 phenomena of "fogging" can be reduced.

The image forming apparatus of the present invention is used in copying machines, laser printers, and the like.

[Prior Art] In a copying machine or a laser printer, a static 1llW1 image formed on a photoreceptor is converted into a two-component I! 2. Description of the Related Art An image forming device is used that creates a visible image using toner in a developer and transfers the visualized toner image onto copy paper or the like. In such an image forming apparatus, the toner in the developer stored in the developer container is consumed and reduced, so it must be replenished as appropriate.

Therefore, conventionally, as a method for regularly replenishing an appropriate amount (an amount commensurate with the amount consumed) of toner in synchronization with the image forming operation during (1) developing device WlfFvj, there have been two methods: (1) placing a magnetic sensor in the developing device; (ATDC), which detects the amount of toner in the developer and replenishes the toner by bringing the detected value closer to the reference value; A method (AIDC) is used in which a toner image is formed on the surface, the density of the toner image is optically detected, and toner is replenished by bringing the detected value closer to a reference value. (2) As a method of forcibly (non-regularly) replenishing an appropriate amount of toner (an amount commensurate with the consumption amount or expected consumption amount), regardless of the image forming operation, a "toner density low" warning display is displayed. There is a method for replenishing a predetermined amount of toner by commanding forcible toner replenishment using an external input means, when a toner shortage is expected in advance due to continuous printing of documents with dark images, etc. Proposed.

In the above method (2), the method (1) assumes replenishment of toner consumption due to the image forming operation for a standard AS document, and the replenishment operation is also Due to the fact that this is done within a limited short period of time during the image forming operation (therefore, the amount of replenishment is also reduced), for example, if the amount of toner erased is excessive than the standard due to a series of documents with dark images, This method has been proposed in view of the fact that the method (1) tends to be unable to supply sufficient toner.

[Problems to be Solved by the Invention] A two-component developer consisting of toner and carrier is stirred in a developing device and triboelectrically charged. Due to the rIJ frictional charge, the toner and carrier are strongly combined to some extent, thereby preventing the so-called "fogging" phenomenon. The "fogging" phenomenon is a phenomenon in which the toner is uniformly and lightly applied to areas on the photoreceptor that do not require development, and as a result, the toner is also uniformly and lightly transferred onto the paper. This is a phenomenon that tends to occur in some cases.

Up! , c! In method (2), there are cases where it is desired to interrupt toner supply and restart the image forming operation. In such a case, if the replenishment operation is simply stopped and image formation is started, the frictional charging becomes insufficient and the "fogging JIJ1 phenomenon" occurs.

The present invention has been made in view of the above circumstances, and it is possible to replenish an appropriate amount of toner as needed. In other words, it is possible to interrupt toner replenishment in the method (2) above. In addition, even when coughing is interrupted, the above-mentioned "fogging" can be prevented by stirring the toner and carrier sufficiently.
This is an attempt to prevent this phenomenon.

Means and operation for solving aS between E and A] The image forming device of the present invention includes a developing device that visualizes electrostatic S* with toner, and a stirring device that stirs a two-component developer in the developing device. a toner replenishing means for replenishing toner into the developing device; a replenishment input means for instructing an unsteady replenishing operation by the toner replenishing means; and a stop input means for instructing a stop of the unsteady replenishing operation. - a control means for stirring the two-component developer by driving the stirring means for a predetermined period of time after stopping the replenishment operation when the stop input means commands to stop the unsteady replenishment operation; has.

In the above configuration, when the replenishment input means commands non-regular toner replenishment unrelated to toner replenishment during image forming operation, and then commands to interrupt the toner replenishment, the replenishment input means commands for a predetermined period of time ( The predetermined time can be determined depending on, for example, the replenishment duration time.) The toner and carrier in the developing device are stirred. As a result, the toner and carrier are sufficiently charged *m, and the above-mentioned "fogging" phenomenon is prevented.

[Example] The present invention will be described below with reference to specific examples shown in the drawings.

(Description of the copying machine body) First, the mechanical configuration and copying principle of the copying machine to which the present invention is applied will be explained.

FIG. 1 is an oblique view showing the external appearance of the main body of the copying machine of this embodiment. fI
FIG. 2 is a schematic diagram illustrating the configuration of the vicinity of the developing device of the copying machine.

The copying machine of this embodiment has an optical system 5 that scans the original for exposure and continuously projects a light image corresponding to the original onto the surface of the photoreceptor drum.
(50 to 55), an electrostatic recording section 6 (61 to 69) that records the projected optical image as an electrostatic latent image on the photoconductor drum, and an electrostatic recording section 6 (61 to 69) that records the projected optical image as an electrostatic latent image on the photoconductor drum 61, and a static latent image 1i on the photoconductor drum 61 with toner. A developing device 4 (40-45) that visualizes the toner image, and a transfer unit 7 (71-45) that transfers the visualized toner image onto copy paper.
72), a paper feed/delivery system and constant II unit W1 (not shown) that supplies copy paper and fixes images, and a glass document table 8 on which a document is placed. The control panel 94 (see FIG. 1) and sensor input are detected to perform predetermined operations and displays.

(a) Optical system 5 The optical system 5 includes a light source 50 and mirrors 51, 52, 53, 54.
, a lens 55, and a drive mechanism (not shown), which moves forward and backward along the lower surface of the document table 8, and exposes and scans the document surface during forward movement #J. That is, the reflected light from the original is reflected by the mirror 51.
After being reflected by 52 and 53, it passes through a lens (variable magnification lens block) 55, is further reflected by a mirror 54, reaches a photosensitive drum 61, and a light image corresponding to the original is projected onto the surface of the drum 61. .

The mirrors 51, 52, and 53 are connected to the same exposure scanning motor (
(not shown).

The moving speed of the light source 50 and the mirror 51 is V/N (N: copy magnification) with respect to the circumferential speed rxv of the photosensitive drum 61, and the mirrors 52 and 53 keep the optical path length constant. It is V/2N. On the other hand, the mirror 54 and the lens 55 are driven in conjunction with each other by a magnification setting motor (not shown). Here, the lens 55 moves on the optical axis to change the copying magnification, and the mirror 54 moves and swings to correct the image point.

(b) Electrostatic Recording Unit 6 The electrostatic recording unit 6 includes a photosensitive drum 61 that can be rotated in the direction of the arrow, a main eraser lamp 62 arranged around the drum 61, a sub charger 63, and a sub eraser. It has a lamp 64, a main charger 65, and a blade type cleaning device 69.

A photoreceptor layer is formed on the surface of the drum 61, and the photoreceptor layer is sensitized and charged by passing through the eraser lamp 62, 64 and the charger 63, 65, and the photoreceptor layer is sensitized and charged by the optical system 5. The electrostatic latent image is formed by continuously receiving the optical image in the form of a slit.

(C) Developing FIIKe4 The developing device 4 includes the developing sleeve 42 and the developing sleeve 4.
This is a magnetic brush type device equipped with a magnetic roller 41 built into the magnetic roller 2 and a built-in magnetic roller 41. The developing sleeve 42 has its axis parallel to the axis of the photoreceptor drum 61, and its outer surface faces the outer surface of the photoreceptor drum 61 with a predetermined gap, so that the developing sleeve 42 is inserted into the developer container 45. It is located in In addition,
A developing bias power source 40 is connected to the developing sleeve 42 via a self-bias resistor Ro. Further, as the developer, a two-component developer consisting of toner and magnetic carrier is used.

A toner tank 43 is arranged above the developer container 45,
By rotating the toner replenishment roller 44 that is attached to the bottom of the toner tank 43, the toner in the toner tank 43 is transferred to the developer container 2145 through a notch formed on the circumferential surface of the toner replenishment roller 44. It is configured to be refilled. Therefore, one of the toner supply rollers 44
The amount of toner replenishment per rotation is constant.

Further, a toner concentration sensor 11 is disposed at a predetermined location within the developer container 845, and transmits an electrical signal at a level corresponding to the toner concentration at the predetermined location to the control path 2 via the toner concentration detection circuit 1. ing.

Here, the toner saturation sensor is a magnetic sensor that detects the magnetic permeability of the current rutting agent.

The control circuit 2 is mainly composed of a microcomputer as described above, and when the current 1 [1 is created To (image creation 8#)
In order to carry out regular toner replenishment and unsteady toner replenishment based on the input signal from the toner replenishment switch 91° (FIG. 1), the replenishment roller is driven in accordance with the detection signal from the toner concentration sensor 11, etc. Controls mechanism 3.

(d) The image visualized by the toner such as the transfer portion 7 is transferred to the transfer charger 71
The image is electrostatically transferred onto the copy paper at , and the similar copy paper is separated from the photosensitive drum 61 by the separation charger 72 . Incidentally, after the copy paper is guided to the transfer section 7 by a paper feeder (not shown), it is transferred to a constant I (not shown).
It is discharged from the copying machine via the I device.

(Description of Control Circuit 2) FIG. 3 is a circuit diagram showing details of the control circuit 2 shown in FIG. 2.

As shown in the figure, the control circuit 2 includes a CPU 20 consisting of a 1-chip microcomputer, and the CPLJ 20 includes:
It is connected to other input/outputs and other microcomputers via an interface 21.

The output port PAO of the CPU 20 has a driver IC 31.
A solid state relay (SSR) 32 is connected through the SSR, and the toner replenishing motor 33 can be driven by the 25V AC 'Wiii34. The drive is
The output signal level from PΔO is in a low level state.

Further, a solid state relay (<5SR) 402 is connected to the output boat PA1 via a driver IC 401, and a developing motor 403 is connected to the output boat PA1 by a 100V AC power supply 404.
(The developing motor drives the developing sleeve, magnetic roller, developer stirring member, etc.). Note that driving is performed when the output signal level from the FAI is at a low level, as described above.

Further, a replenishment request display LED (see Fig. 1) 96 is connected to the output boat PA2 via a driver IC 960, and is configured to be lit when the output signal level from PA2 is at a low level. . □ On the other hand, there is a toner replenishment switch 91 on the input capo-PBO.
(see FIG. 1) is connected, and the on state of the switch 91 is inputted to the PBO as a low level signal.

A toner concentration sensor 11 is connected to the input boat PB1 via a toner concentration detection circuit 1, and when the detected toner concentration is lower than a predetermined setting value (5 wt% toner concentration in this embodiment), The state is inputted to PBl as a high level signal.

Further, a print switch 92 (see FIG. 1) is connected to the input port PB2, and when the switch 92 is turned on, a low level signal is input to PB2.

Furthermore, the input boat PB3 has a clear/stop key 9.
3 (see FIG. 1) is connected, and the on state of the switch 93 is represented as a low level signal. The clear/stop key 93 is a key that commands to stop the copy operation and clear the set number during copying, and commands to stop toner replenishment while toner replenishment switch 91 is replenishing toner.

(Operation Description) FIG. 4 is a flowchart showing II ill by the #J&l CPU 20.

For example, the CPLJ20 starts processing when the power is turned on, and first performs initial settings (8102) and sets an internal timer that defines the time and timer count for one routine (8102).
5104).

Next, input processing from various keys, sensors, etc. (8106
), toner replenishment control (S108: detailed below), and display data setting processing (SIIO: detailed below) are executed.

Next, in 8112, it is determined whether the copy operation is possible or not.
1 (see 5118).

If possible, execute copy 11JIII processing (8114: details' described later); if not, execute abnormal processing (8116).
).

Next, the input data at 8106 causes a jam.

Other troubles are detected, and if an abnormality that makes copying impossible is detected, the flag F1 is lowered.

At 5120, the count of the timer used for various 1IIJt2Il is increased, and when the internal timer ends (
3122> Return to step 8106 and repeat the above process.

FIG. 5 is a flowchart showing details of 8108 in FIG.

First, the toner replenishment flag is determined (8202).

This flag is set when the toner replenishment switch 91 is turned on (8) when the copying machine is not in the copying operation.
204, 8206).

When the toner replenishment flag is set, the timer 1 (timer that specifies the duration of toner replenishment) and the timer 1 flag are set (8212, 8214), and the timer 2 flag (timer 2 that specifies the stirring time) is set (8212, 8214). The corresponding flag) is reset (8216).

When the toner replenishment flag is set (8202) and the timer 1 flag is set (8220) (that is, when forced toner replenishment is being performed), the clear/stop key 93 is turned on. (822
2), timer 1 and timer 1 flag are reset, and timer 2 and timer 2 flag are set (82
24.5226.8228). Here, the value of timer 2 is set to 70% of the count value of timer 1 that is counted when timer 1 is reset (8226).
This is just an example, and you may change it accordingly depending on the circumstances.
Further, it may be made variable according to the count value of timer 1. Alternatively, it may be a predetermined value unrelated to timer 1.

The clear stop key is not pressed (8222),
If timer 1 has not ended (S230), li!
The image motor and toner supply motor are turned on (23
2) During this period, toner supply continues. Note that timer 1
Upon completion of , the timer 1 flag is reset (8
230, 8236 > If the timer 1 flag is reset and the timer 2 flag is set (8220, 82
40), the toner replenishment motor is set to the off state M (8244>).As a result, toner replenishment is stopped, but since the developing motor remains in the off state, stirring continues. Upon completion of , the timer 2 flag is reset (8242.8246).

When the timer 2 flag is reset, the toner replenishment flag is reset and the developing motor is turned off (82
40.5250.8252>.

In the manner described above, unsteady toner replenishment control is executed.

FIG. 6 is a flowchart showing details of 8110 in FIG.

That is, if a paper jam, paper empty, or toner empty is detected (8302, 5310
, 8320) sets corresponding display data (8304, 8312, 8322). The vapor jam, paper empty, or toner empty is displayed on the segment display 194 as a corresponding predetermined pattern (8330). In addition, if none of vapor jam, paper empty, or toner empty is detected, segment display! Copy number data is displayed on I94 (8324
).

FIG. 7 is a flowchart showing details of 8114 in FIG.

In other words, the copy start flag F2 should be set on condition that the print key 92 is manually operated.8402.5404.8406
), performs various II controls necessary for copying operations, such as paper feeding/conveyance control, optical system a control, and control around the photoreceptor (
8410, 8412, 8414).

Thereafter, after the copy is completed, the flag F2 is reset (8416.8418).

The image forming device according to this embodiment operates as described above.

[Effects] As described in detail above, the present invention provides an image forming apparatus that can perform unsteady toner replenishment unrelated to image forming operation and stop the toner replenishment in response to an external command, This is a device that stirs the developer in the developing device for a predetermined period of time when the process is stopped.

As is clear from the examples described, according to the present invention, the developer is sufficiently stirred! ! ! ! Because of frictional charging, the "fogging" phenomenon is effectively prevented.

In addition, since necessary and sufficient toner can be replenished by non-regular toner replenishment, toner shortage can be avoided even if dark documents continue to be produced.

Furthermore, if it is desired to resume copying during irregular toner replenishment, the replenishment can be promptly stopped.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the appearance of the main body of the copying machine of this embodiment, and FIG. 2 is a schematic diagram illustrating the structure of the vicinity of the developing device of the copying machine. Figure 3 shows the control circuit 2 shown in Figure 2.
FIG. 2 is a circuit diagram showing the aT line of FIG. FIG. 4 is a flowchart showing control by the CPU 20. FIG. 5 is a flowchart showing details of 8108 in FIG. FIG. 6 is a flowchart showing details of 8110 in FIG. FIG. 7 is a flowchart showing details of 8114 in FIG.

Claims (2)

[Claims] (1) a developing device that visualizes an electrostatic latent image with toner; a stirring device that stirs a two-component developer in the developing device; and a toner replenishing device that replenishes toner in the developing device; a replenishment input means for commanding an unsteady replenishment operation by the toner replenishing means; a stop input means for commanding a stop of the unsteady replenishment operation; and a stop input means for instructing a stop of the unsteady replenishment operation. and a control means for stirring the two-component developer by driving the stirring means for a predetermined period of time after the replenishment operation is stopped. (2) The image forming apparatus according to claim 1, wherein the control means determines the predetermined time depending on the duration of the non-regular replenishment operation.