JP3016736B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus in which a toner cartridge is detachably mounted on a main body of a developing device.

[0002]

2. Description of the Related Art In various image forming apparatuses such as copying machines, printers, and facsimile machines having a photoconductor, a developing device is provided so as to develop an electrostatic latent image formed on the photoconductor. Further, a toner cartridge for storing new toner is detachably mounted on the developing device, and new toner is supplied from the toner cartridge to the toner tank of the developing device.

At this time, when all the toner in the toner cartridge is replenished into the toner tank of the developing device, the remaining empty toner cartridge is used as a waste toner collecting container of the photosensitive member cleaning mechanism. There is something.

On the other hand, when the toner in the developing device is consumed and the amount of residual toner reaches a certain amount, a predetermined control mechanism performs a toner end display and shifts to an image forming disabled state so that the image forming process is prohibited. Has become.

[0005]

However, in such a conventional image forming apparatus, the above-mentioned toner end occurs during an image forming operation such as copying, so that an image cannot be formed. Also, if the toner supply mode is executed a plurality of times by opening and closing the door, a small number of images can be formed. When the main switch is turned on and off, the toner end state, that is, the above-described image formation impossible state is cleared.

For this reason, conventionally, the user frequently returns the toner end state to the image forming state by the above various means without replacing the toner cartridge in order to improve productivity at the time of toner end. I have.

However, if an image is formed in such an imperfect state, the image quality may be deteriorated such as a decrease in image density, and problems such as carrier scattering may occur. ing.

Further, in an apparatus using an empty toner cartridge as a waste toner collecting container of the photosensitive member cleaning mechanism, the empty toner cartridge may be mistakenly removed from the apparatus in an erroneous manner. When the toner is discharged into the apparatus and the inside of the apparatus is contaminated with toner, the new toner and the discharged toner are mixed with each other, which may cause a problem in image and mechanical quality.

Accordingly, it is a first object of the present invention to provide an image forming apparatus capable of preventing inferior deterioration of image quality due to image formation at the time of toner end and problems such as carrier scattering. It is a second object of the present invention to provide an image forming apparatus capable of preventing an erroneous removal of an empty toner cartridge when the empty toner cartridge is used as a waste toner collecting container of a photoconductor cleaning mechanism.

[0010]

According to the first aspect of the present invention,
In order to solve the above-described problems, an image forming apparatus including a developing device, a toner cartridge mounted on the developing device and supplying toner to the developing device, and a detecting unit configured to detect whether the toner cartridge is mounted is provided. When the detection means detects that the toner cartridge is detached after the toner end, and the detection means detects that the toner cartridge is mounted within the minimum time To 'required for replacement of the toner cartridge, the image forming operation is stopped. Control means for maintaining the disabled state is provided.

[0011]

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 8, the photosensitive drum 1 as a latent image carrier is rotationally driven in a counterclockwise direction by a drive mechanism (not shown).
The photoconductor drum 1 is formed of, for example, an organic photoconductor (OPC), and is initially charged uniformly to a predetermined potential by a charging charger (not shown), and a light image formed by an exposure optical system (not shown). An electrostatic latent image is formed by the imaging operation.

Further, a developing sleeve 20 made of a cylindrical member as a developer carrying member is provided in a developing casing 201 of the developing device 2 disposed near the photosensitive drum 1.
2, a part of the developing sleeve 202 is exposed from the opening provided in the developing casing 201 toward the photosensitive drum 1 side. The developing sleeve 202 is formed by forming a non-magnetic material such as aluminum into a hollow cylindrical shape, and is rotationally driven clockwise by a drive mechanism (not shown). Are arranged to face each other with a certain gap. A transition area of the toner, that is, a development area is formed in a portion where the development sleeve 202 and the photosensitive drum 1 are opposed to each other.

On the other hand, a developing magnet body 203 is provided inside the developing sleeve 202, and a magnetic carrier is formed on the outer surface of the developing sleeve 202 by a magnetic force generated from each magnetic pole of the developing magnet body 203. A magnetic brush made of toner is spiked.

The end portion of the magnetic brush is in elastic contact with the surface of the photosensitive drum 1 in the above-described developing area. A DC developing bias voltage is applied to the developing sleeve 202 from a power supply circuit (not shown) so that the DC developing bias voltage prevents background contamination and adjusts the density of a formed image. Has become.

The developer constituting the magnetic brush is initially stored in the developing casing 201, and is pumped up to the developing sleeve 202 while being stirred by the paddle wheel 204. The developer pumped up by the developing sleeve 202 is conveyed to the developing area as a magnetic brush as described above, and in the middle thereof, the developer is magnetically moved by the pre-doctor 205 and the developing doctor 206 arranged close to the developing sleeve 202. The brush is cut off, whereby the amount of the developer is regulated.

Excess developer removed from the developing sleeve 202 by the pre-doctor 205 and the developing doctor 206 is transferred to the pre-doctor 205 and the developing doctor 2.
Agitated to the inclined plate of the stirring separator 207 along the inner curved surface of No. 06, and further, as shown in FIG. It is dropped so as to be returned to the area behind the paddle wheel 204 while being moved. Further, a plurality of developer intake ports are formed in the inclined plate, and the developer dropped through the developer intake ports is agitated and moved to the rear side in the lateral direction by the transport action of the auger 208, and the opposite end portion is formed. From above to a region above the paddle wheel 204.

A toner tank 210 is connected to a rear end portion (left end portion in FIG. 8) of the developing casing 201, and a toner cartridge 211 is detachably attached to the toner tank 210. When the shutter of the toner cartridge 211 is slid open, new toner in the toner cartridge 211 is supplied to the toner tank 210. An agitator 212 is provided in the toner tank 210, and the toner agitated by the agitator 212 is reduced by a required amount by a rotating and conveying action of a toner supply roller 213 provided at an outlet portion of the toner tank 210. 201.

The rotation of the toner supply roller 213 is controlled by a toner supply CL (not shown).
Further, the toner supplied to the developing casing 201 is supplied to the paddle wheel 204 by the rotation and transport action of the developing agitator 214, and is stirred by the various stirring mechanisms described above so that the toner and the developer have a uniform developer concentration. The Rukoto. The toner cartridge 211
The toner tank 21 as shown in FIG.
It is configured to be attached and detached in a slide shape in the horizontal direction (the left-right direction in FIG. 9) with respect to 0.

On the other hand, a toner cartridge switch 215 constituting a toner cartridge detecting mechanism is provided at a rear end portion of the toner tank 210, and the presence or absence of the toner cartridge 211 is determined by the toner cartridge switch 215. It is to be detected. The signal from the toner cartridge switch 215 is input to an input / output controller of a control device described later. Further, as shown in FIG. 6, a P sensor (light reflection type photo sensor) 3 of an image density detecting mechanism is arranged opposite to the photosensitive drum 1.

As shown in FIG. 7, the P sensor 3 in this embodiment is an LED 30 as a light emitting element.
1 and a phototransistor 302 as a light receiving element. On the other hand, a reference density plate 304 is provided below one end of the contact glass 303, and a light image of the reference density plate 304 is exposed on the photosensitive drum 1 to form an electrostatic latent image of a P sensor pattern. It is formed on the photosensitive drum 1.

The electrostatic latent image of the P sensor pattern is developed by the developing device 2 and an LED of the P sensor 3 is applied to the obtained toner visible image of the P sensor pattern.
The inspection light from 301 is irradiated, and the reflected light from the P sensor pattern is received by the phototransistor 302. Further, a signal corresponding to the reflected light from the P sensor pattern is output from the phototransistor 302 to the OP amplifier 305.

The output signal from the P sensor 3 is input to the A / D converter 401 of the main control unit 4 and the A / D converter 40
The output signal corresponding to the image density is output from 1 to the input / output controller. The toner density of the toner visible image of the P sensor pattern detected in this way is captured as the toner density of the developer in the developing device 2, and a control operation such as toner supply is performed based on the toner density.

Specifically, when the sensor output obtained from the erase area before and after the toner visible image of the P sensor pattern is V _SG , and the sensor output obtained from the toner visible image of the P sensor pattern is V _SP The comparison between the reference voltage V _SG / 8 and V _SP is performed in a main control unit not shown.

For example, when V _SG / 8 <V _SP , the toner supply CL is turned on to perform toner supply.
As a result, the developer density is increased, and the density of the toner visible image of the P sensor pattern on the photosensitive drum 1 is kept constant.

FIG. 4 shows a control system of the copying apparatus according to the present embodiment. As shown in the figure, a liquid crystal display control unit 501 provided in the operation unit 5
Controls the character pattern memory 503 and the graphic memory 504, and controls the character pattern memory 503 and the graphic memory 504.
Are displayed on the liquid crystal display unit 502.

An input signal from the key 505 is once input to the CPU 402 in the main controller unit 4 through the key display controller 506.
A predetermined output is performed to the liquid crystal display control unit 501 through the interface 507 in the operation unit 5 to perform a predetermined display. Reference numeral 403 indicates a read-only memory for control (ROM), reference numeral 404 indicates a nonvolatile memory (RAM), and reference numeral 405 indicates an input / output controller.

In this embodiment, the toner end detection shown in FIG. 5 is performed. First, the data D0, D1, and T in each step are data that are reset when the toner cartridge is replaced, and are all stored in the nonvolatile memory (RAM) 404. Of these, the timer T is a timer value for measuring the ON time of the toner replenishing CL, the data D0 is adapted to be set when the count-up result is a predetermined time T ₀ or more.

Here, the toner tank 210 is filled with the toner of one toner cartridge 211 and the time required to eliminate the residual toner in the toner tank 210 by continuously rotating the toner supply roller 213 is represented by t.
Then, it is set so that T ₀ <t with respect to the predetermined time T ₀ .

The image density detection by the P sensor is executed during the copying operation. When the detection result is V _SG / 8 <V _SP (step 1), the data D0 is confirmed (step 2), and when the data D0 is reset, the toner supply CL is reset.
Is turned on and the toner supply roller is driven to rotate (step 3), whereby toner is supplied into the toner tank 210. At this time, the timer T is counted up in conjunction with turning on the toner supply CL (step 4).

Next, the timer T is compared with T ₀ (step 5), and if T ≧ T ₀ , “near end”
The display is lit on the display (step 6), and the data D
0 is set (step 7). When the data D0 is set, the data D1 is confirmed (step 8), and when the data D1 is set, the copying operation is interrupted and "interruption" is displayed on the display unit (step 9). When the data D1 is reset (step 10), a toner supply operation is performed (step 1).
1).

FIG. 1 shows a toner end reset method after the toner end. That is, in the toner end flow shown in FIG. 1, when the data D0 and D1 are set, the toner end is detected and the copying operation is interrupted.
"Toner end" and "toner cartridge replacement" as shown in FIG. 2 are displayed on the display unit (step 1), and the user is prompted to replace the toner cartridge 211.

At this time, the toner cartridge switch 2
The status signal of No. 15 is confirmed (step 2), and when the switch is reset (when the toner cartridge 211 is not set), the timer T 'is counted up (step 3). Here, 'When, T' the minimum time required for replacement of the toner cartridge 211 T ₀ when ≧ T ₀ ', That
The minimum time required to replace the toner cartridge
When a predetermined period of time has elapsed , the data D0 and D1 are reset, and the toner end is reset (step 4), thereby returning to the copy state (step 5).

As described above, in this embodiment, once the developing device 2 is shifted to the toner end state, the image forming operation is continued until the toner cartridge detecting mechanism detects that a new toner cartridge 211 is mounted. The disabled state is maintained as it is. That is, the user cannot return the toner end state to the image forming enabled state without replacing the toner cartridge 211 at the time of toner end.

Further, in this embodiment, the toner in the toner cartridge 211
When the toner is replenished to zero, the remaining empty toner cartridge 211 is used as a waste toner collecting container of the photoconductor cleaning mechanism.

When the toner cartridge detecting mechanism detects that the empty toner cartridge 211 has not been mounted, the empty toner cartridge 2
Until the mounting of the cartridge 11 is detected, the image forming disabled state is maintained, and a display urging the user to set the toner cartridge as shown in FIG. 3 is displayed.

Therefore, the toner tank 2 of the developing device 2
10, the toner cartridge 211 is replenished with new toner, and the empty toner cartridge 211 is not removed unless the toner cartridge detection mechanism detects that the toner cartridge 211 is still attached without being removed. The state is maintained as it is. That is, the user can use the empty toner cartridge 21
1 cannot be mistaken for an unnecessary one and removed from the apparatus.

[0038]

In the invention according to one of claims according to the present invention, when the developing device is once shifts to the toner-end condition, after the preparative toner cartridge withdrawal, also mounted is detected by the toner cartridge detection mechanism, Required from detachment to installation
Time to replace a new toner cartridge
When the time is shorter than the short time, a new toner cartridge
Without cognition and is replaced, its or <br/> or you keep the imaging disabled state. That user, new at the time of the toner end
The toner end state cannot be returned to the image forming enabled state unless the toner cartridge is replaced.

As described above, at the time of toner end of the developing device, there is provided a control mechanism for maintaining the image formation disabled state until the toner cartridge detection mechanism detects the installation of a new toner cartridge. Accordingly, the image operation at the time of the toner end can be completely prohibited, thereby preventing the deterioration of the image quality due to the image formation at the time of the toner end and problems such as carrier scattering.

[0040]

[0041]

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a toner end reset procedure by a control device according to an embodiment of the present invention.

FIG. 2 is a plan view showing display contents at the time of toner end.

FIG. 3 is a plan view showing display contents at the time of toner end.

FIG. 4 is a block diagram illustrating a configuration of a control device according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a toner end detection procedure.

FIG. 6 is a side view schematically showing a P sensor detection mechanism.

FIG. 7 is a block diagram schematically showing a P sensor detection mechanism.

FIG. 8 is a side view illustrating an example of a developing device provided in an image forming apparatus to which the present invention is applied.

9 is an external perspective view showing a part of the developing device shown in FIG. 8 in an enlarged manner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 developing device 3 P sensor 202 developing sleeve 205 developing doctor 210 toner tank 211 toner cartridge 215 toner cartridge switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/08 112 G03G 21/00 510 G03G 15/08 114

Claims (1)

(57) [Claims] An image forming apparatus comprising: a developing device; a toner cartridge mounted on the developing device to replenish toner to the developing device; and a detecting means for detecting whether or not the toner cartridge is mounted. When the detection unit detects that the toner cartridge has been mounted within the minimum time To 'required for replacing the toner cartridge after the detection unit detects that the toner cartridge has been detached, the image forming disabled state is maintained. An image forming apparatus comprising: