JPS638767A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate unnecessary copying by providing a stop processing means which inhibits following image forming operations after the end of the current image forming operation if the output of a toner level sensor is in a level to indicate the absence of a toner during this image forming operation. CONSTITUTION:It is discriminated whether the output of a toner level sensor 30 is in a level B' indicating the absence of the toner or not, and it is discriminated whether the output of the sensor 30 is in a level lower than a proper level A' or not if this output is in the level higher than the level B'. If the output of the toner level sensor 30 is in the level B' indicating the absence of the toner, the machine operation is temporarily stopped after the end of the image forming operation, and a toner T is replenished to a developing device once if a new toner cartridge is loaded. If the toner density of a two- component developer agitated in the developing device is in a certain level C' higher than level B' indicating the absence of the toner in such case, toner supply is repeated until the time of a timer expires, and the machine operation is stopped when time expires.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention relates to an image forming apparatus such as an electronic copying apparatus, and in particular to an image forming apparatus that uses a two-component developer consisting of toner and a carrier to carry an image. The present invention relates to an improvement in an image forming device that makes a latent image on a body visible.

(Prior Art) In a conventional image forming apparatus of this type, a toner concentration detection means detects the toner concentration of a two-component phenomenon agent stirred in a phenomenon device during an image forming operation, and this detection output is detected by a toner concentration detection means. When the toner out level is indicated, immediately end the image forming operation even if it is in the middle of the image forming operation, or after repeating the image forming operation for the set number of sheets with the toner out level remaining at the toner out level,
Subsequent image forming operations were prohibited.

However, if the imaging operation is terminated in this way, an unusable copy will be obtained;
In the former case, incomplete copies will be obtained, and in the latter case, when the setting is made to take multiple copies, unusable copies will be obtained for the large number of copies. There was a problem.

(Problems to be Solved by the Invention) Conventionally, as described above, unusable copies are obtained, which results in wasted paper, and furthermore, usable normal copies (in order to be photographed) have to be reproduced. Therefore, the actual copying time becomes longer.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that can eliminate wasted copying.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, an image forming apparatus that performs two-component development according to the present invention, when a toner-free level is indicated during an image forming operation, The image forming apparatus is characterized by having a stop processing means for prohibiting the next and subsequent image forming operations after the forming operation is completed.

(Function) During the image forming operation, in the developing device, the toner concentration of the two-component developer stirred by the stirring means is detected by the toner concentration detection means. When this detection output indicates the toner out level, the stop processing means waits until the image forming operation is completed and prohibits the next image forming operation. You can obtain only valid copies that do not include invalid copies such as.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a perspective view showing the appearance of an image forming apparatus to which the present invention is applied.

In the figure, 1 is the main body of the copying machine. A paper feed cassette 2 that can automatically or manually feed paper is installed on the right side of the copying machine main body 1, and a paper output tray 3 is installed on the left side of the cassette 2, in which originals (not shown) are placed. A document table 4 is provided on the upper document placement plate, which is capable of reciprocating in the left-right direction (in the direction of arrow a). In the figure, reference numeral 5 indicates a display 6.5 provided on the front edge of the upper surface of the copying machine main body 1. This is an operation display section including a numeric keypad 7, an exposure setting volume 8, a print key 9, and the like.

Next, the internal mechanism of the copying machine main body 1 will be explained with reference to FIG.

In the figure, reference numeral 10 denotes a drum-shaped photoreceptor as an image carrier rotatably supported approximately at the center of the copying machine main body 1, and is moved in the direction of the arrow in synchronization with the document table 4 by a drive FMm (not shown). It is designed to be rotatably driven. This photoreceptor 1
0, a document image uniformly charged by a charger 11 and uniformly irradiated by an exposure lamp 12 is imaged onto a photoreceptor 10 by a focusing light transmitter (product name: SELFOC lens array) 13. to form an electrostatic latent image, and develop the electrostatic latent image by applying a developer (hereinafter referred to as toner) to this electrostatic latent image using a developing device described later. (referred to as an image) is sent to the transfer charge t14 side.

The transfer charge v14 is formed on the photoreceptor 10 on the copy paper P or P- that is fed from the paper feed cassette 2 that is automatically or manually fed via the paper feed roller 15 and the registration roller pair 16.16. It is used to transfer the toner image, and after the transfer, iff P or P' for copying is as follows.
It is peeled off from the top of the photoreceptor 1o by a peeling charger 17 using AC corona discharge and passed through a conveyance path 18 to a fixing device 19.
The toner acid is melted and fixed by the ejection roller pair 20.20.
The paper is discharged onto the paper discharge tray 3.

On the other hand, the residual toner on the photoconductor 10 after the toner image is transferred onto the copy paper P or P- is cleaned by the cleaning device 21, and the electric potential on the photoconductor 10 is lowered to a certain level by the static elimination lamp 22, and the next Make the copy operation possible.

Further, in the copying machine main body 1, an upper frame and a lower frame (not shown) are pivotally supported so as to be openable and closable at a desired angle (for example, 30°) to each other, and a photoreceptor 1 is attached to the upper frame.
0, and a charger 11 around the photoreceptor 10,
exposure lamp 12, focusing light transmission body 13, cleaning device 21,
Each device such as a static elimination lamp 22 and a developing device to be described later is attached by appropriate means to constitute an upper unit, and a transfer chip is attached to the lower frame. 14. Peeling 1! - image t17, fixing device 19 and ejection roller pair 20.
Each device such as 20 and other open grooves such as a power supply section (not shown) are attached to form a lower unit, and both units are connected to each other with the transport path 18 of copy paper P or P- as a boundary.
I can be closed to facilitate repairs and inspections.

The reference numeral 23 in the figure is a developing device positioned around and facing the photoreceptor 10. The developing device 23 includes a supply main body 24 that adheres and supplies toner T supplied from a toner cartridge (to be described later) to the surface of the photoreceptor 10 in a brush-like manner. A doctor is placed on a magnet roller 25, which is composed of a rotating sleeve of non-magnetic material and a fixed magnet, which are placed in opposition to each other so as to supply the toner below the surface. 26, and an agitation roller 27 for agitating the toner T.

A toner level sensor 30 using a magnetic sensor is installed behind the stirring roller 27 in a sensor part 31 to detect the toner concentration.

In addition, 32 is a toner cartridge, 33 is a hopper, 3
4 is a replenishment port, and 35 is a developer replenishment roller. Also below is toner.

Next, a control circuit for controlling the flow of toner from the replenisher 32 to the developing device 23 based on the detection output of the toner concentration detector 30 is shown in FIG.

The control circuit shown in FIG. 3 uses a microcomputer 41 of the image forming apparatus as a control center, and a toner level sensor 3 is connected to the input side of the microcomputer 41.
A detection code of 0 is added via the A/D converter 42,
Predetermined outputs are sent to a solenoid 431 for opening and closing the supply port 34, an analog switch 44, a display panel 45, etc., which are connected to the output side of the microcomputer 41, respectively.

In such a control circuit configuration, the microcomputer 41 controls the fourth controller according to the system program.
Execute the process shown in the figure.

First, when the power of the image forming apparatus is turned on, initial setting is performed (step 401), and at this time, data of toner density to be used as a toner-free level stored in the memory is read.

Next, upon receiving the detection signal from the toner level sensor 30 (step 402), it is confirmed that the toner concentration of the developer in the developing device 23 is at the appropriate density level, and if it is at the appropriate density level, a normal copying operation is performed. (Step 403).

In this way, when a normal copying operation is performed, the toner level sensor 30 is operated separately (step 404).
, step 405 until the set number of copies are completed.
(No), steps 403 to 405 are repeated, and when the copying is completed, at Step 405 (Yes), the process enters a standby state.

Steps 402 and 4 of such main processing
In each process of step 04, a subroutine process as shown in FIG. 5 is executed to detect the toner concentration level of the phenomenon agent in the phenomenon device 23.

This nub-tin process is started when the toner level sensor is turned ON, and the toner concentration is determined using the sensitivity curve X given to the toner concentration (weight ratio concentration) level sensor output characteristic as shown in FIG. control. However, in FIG. 6, A is the proper toner density value, B is the density value treated as if there is no toner, A- is the proper i11 degree level corresponding to the proper toner density value A, and B' is treated as if there is no toner. This is the toner-free level corresponding to the density value B. Note that the potential level of the density value C, which is slightly higher than the density value B which is treated as having no toner, is shown as C'.

First, it is determined whether the output of the toner level sensor 30 is the toner empty level B- or not (step 501), and if the toner level is higher than the toner empty level (step 501 negative), it is lower than the appropriate level A'. It is determined whether the density level is reached (step 502).

If the appropriate level is A' (step 502 negative), the fourth
Return to the main routine shown in the figure. If the appropriate concentration limit level is lower than the appropriate level A' (step 50
2 (Yes), the replenishment port 34 is opened by driving the solenoid 43, so one dose of toner T is supplied from the toner cartridge 32 to the developing device 23, and at the same time, the stirring roller 27 is rotated while the machine operation is stopped. (hereinafter referred to as idle rotation of the stirring roller) is performed (step 5).
03). When the processing in step 503 is completed, the process returns to step 501 and the determination in step 502 is executed again, so steps 501 to 503 are repeated until the output of the toner level sensor 30 reaches the appropriate density level.

On the other hand, if the output of the toner level sensor 30 is the toner-free level B- (step 501 affirmative), a process of temporarily stopping the machine vJ operation is performed after the image forming operation is completed (step 5o4). Next, the transfer charger 14 and the peeling charge 1-17 are turned off, the exposure lamp 12 and the charger 11 are turned off, the static elimination lamp 22 and the motor are turned on, and the fixing lamp is turned on (step 505). Next, at the same time as the 30 second timer is turned on (step 506), the supply port 34 is opened by driving the solenoid 43;
When the toner cartridge 32 is newly loaded, the toner T is supplied from the developing device 23 to the developing device 23 once (step (507)).

At the time when the toner T is replenished once to the developing device 23, the toner concentration of the two-component developer being stirred in the developing device 23 is constant and higher than the toner empty level B-, and the level is C'. If (step 508 affirmative), step 5
Until the timer 04 times up (step 50)
9), steps 507 to 509 are repeated. When the timer expires (Yes at step 509), a toner empty message is displayed on the display panel 45 (step 510), and the machine operation is stopped (step 511).

However, if it returns to the constant level C' in step 508, the process goes through step 512, enters the standby state (step 513), and returns to the main routine of FIG. 4.

For this reason, in one embodiment of the present invention, during the copying operation in step 403, the toner level sensor 3
When the output of indicates the toner-free level B' (step 5
After the image forming operation is completed, the machine operation is temporarily stopped (step 504), and since toner is not replenished in step 507 in this case, it is determined in step 508 that the machine operation is temporarily stopped for 30 seconds. A time-up output is also generated in the timer (step 509 affirmative), and the machine operation is stopped (step 511).

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent copying with imperfections and copying a large number of copies with unclear shading.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the appearance of an image forming apparatus to which the present invention is applied, FIG. 2 is a view showing the mechanical structure of the image forming apparatus, and FIG. 3 is a main part of an embodiment of the present invention. A diagram showing the circuit configuration,
FIG. 4 is a flowchart showing the main routine of an embodiment of the present invention, FIG. 5 is a flowchart showing the main operations of the structure of the present invention, and FIG. 6 is a diagram showing the toner concentration-sensor output characteristic. 23... Developing device 27... Stirring roller 30.
... Toner level sensor 32 ... Toner cartridge 33 ... Hopper 34 ... Supply port 41 ...
Microcomputer 43...Solenoid

Claims (2)

[Claims] (1) a stirring means for stirring a two-component developer consisting of toner and a carrier; a toner concentration detection means for detecting the toner concentration of the two-component developer stirred by the stirring means;
An image in which a latent image on an image carrier is made visible by a developing device including a toner concentration control means for controlling the amount of toner supplied from a toner replenishing device based on the detection output of the toner concentration detection means. The forming apparatus is characterized by comprising a stop processing means for prohibiting subsequent image forming operations after the end of the image forming operation when the detection output of the toner density detecting means indicates a toner-free level during the image forming operation. Image forming device. (2) The stop processing means prohibits subsequent image forming operations after a certain period of time has elapsed since the end of the image forming operation when the detection output of the toner density detecting means indicates a toner-free level. An image forming apparatus according to claim 1.