JP2006154148A - Development apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development apparatus capable of discharging only the residual toner without wastefully discarding toner which can be normally used. <P>SOLUTION: In the development apparatus where toner replenishment is performed by a toner replenishment means 7, the residual toner is forcibly consumed from a replacement request of a toner replenishment means to start of toner replenishment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a developing device and an electrophotographic image forming apparatus equipped with the developing device.

  In a developing device capable of replenishing toner by replacing toner replenishing means such as a toner bottle and a toner cartridge, the toner remaining in the developing device before setting the new toner replenishing means when replacing the toner replenishing means Includes many which exhibit charging characteristics and particle size distribution that are difficult to use under normal development conditions, and often remain even after a plurality of replacements of toner replenishing means.

Since these residual toners have been exposed to agitation for a long period of time, they also drive in and dissolve out additives, failing to meet the conditions originally required for their physical properties, and in subsequent printing, such as density reduction and scumming This is a factor that causes image quality deterioration and contamination such as toner scattering and toner overflow.
An object of the present invention is to provide a developing device and an image forming apparatus that can discharge only residual toner that causes various problems without wastefully disposing normally usable toner. .

In order to achieve the above object, a first aspect of the present invention provides a developing device comprising a toner replenishing device that replenishes toner in the developing device and a control means, wherein the control means is a toner replenishing means replacement request. And a toner forcible consumption operation for forcibly consuming the remaining toner after the toner supply means is replaced and before the start of toner supply.
The invention according to claim 2 is characterized in that, in the developing device according to claim 1, the developing device having a determining means for determining the time and the end timing of the forced toner consumption operation.
According to a third aspect of the present invention, in the developing device according to the second aspect, the determining means is mainly characterized by a developing device which is data obtained in advance.
According to a fourth aspect of the present invention, in the developing device according to the second aspect, the determining means is characterized by a developing device which is a toner amount / density detection sensor.
The invention according to claim 5 is characterized in that, in the developing device according to claim 2, the time and the end timing of the forced toner consumption operation are variable.
According to a sixth aspect of the present invention, in the developing device according to the first aspect, a toner forcible consumption operation is mainly characterized by a developing device that is operated by a toner end.
According to a seventh aspect of the present invention, in the developing device according to the first aspect, the toner forcible consumption operation is mainly characterized by a developing device in which toner near-end is performed.
According to an eighth aspect of the invention, an image forming apparatus including the developing device according to any one of the first to seventh aspects is the main feature.

  According to the present invention, it is possible to discharge only toner that is difficult to be used for actual image formation in the minimum necessary operation time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an image forming unit of an image forming apparatus according to an embodiment of the present invention. Around the image carrier 1, a charger 2, a developing device (developing device) 3, a toner adhesion amount detection sensor 4, a transfer device 5, and a cleaning device 6 are arranged.
The developing device 3 includes a developing roller 31, a stirring screw 32, a toner amount / density detection sensor 33, a case 34 that supports these, and a control unit 40. A toner bottle 8 that can be attached and detached is provided on the developing unit 3, and the toner bottle 8 and the case 34 are connected via a toner supply port 7. The electrophotographic process operation is well known and will be omitted. The toner bottle 8 constitutes a toner supply device (toner supply means).
One of the characteristic configurations of the present invention is that in a developing device including a toner replenishing device that replenishes toner in the developing device 3 and a control means (CPU or the like), the control means fulfills certain conditions. Then, a toner forced consumption operation for forcibly consuming the remaining toner is performed between the toner supply means replacement request output and the toner supply start after the operator replaces the toner supply means 8 based on the request. In the point.
Further, it is also characterized in that it has determination means for determining the time and end timing of the forced toner consumption operation. This determination means is, for example, data obtained in advance (data relating to determination of the time and end timing of the forced toner consumption operation). Alternatively, the determination means is a toner amount / density detection sensor 33. In addition, since the time and end timing of the toner forced consumption operation can be made variable, it is possible to cope with changes in the situation.

FIG. 2 is a flowchart showing the operation when the toner end is detected. The toner end in the case 34 of the developing device 3 is detected by the toner amount / density detection sensor 33 (S1). In the conventional apparatus, the control means stops operation at this stage, displays a request to replace the toner bottle (to the display unit 41), prompts the operator to replace the toner bottle, and replenishes the toner after replacing the toner bottle. Return to the printable state.
In the present invention, after the toner end is detected, the control unit 40 forms an image on the image carrier 1 in order to discharge the residual toner in the developing device 3, and consumes the toner (S2). The toner image on the image carrier 1 formed at this time is collected by the cleaning device 6 without being transferred to the paper.
After the toner forcible consumption operation, the toner bottle replacement request is displayed for the first time to prompt the replacement of the toner bottle 7 (S3). After the replacement of the toner bottle (Y in S4), the toner replenishing operation is performed until the inside of the developing device 3 reaches an appropriate amount of toner as in the conventional case (S5).
FIG. 3 is a flowchart showing the operation when toner near-end is detected (No. 1). Generally, an apparatus is designed to display a toner bottle replacement preparation request by detecting the toner near end before detecting the toner end and requesting replacement of the toner bottle 7, and to notify the operator that the toner end is near by the display unit 41. In many cases, the operator may replace the toner bottle at this point. The operation corresponding to this will be described with reference to FIG.
When the toner near end is detected (S1), a toner bottle replacement preparation request is issued (S2). If the toner bottle 7 is replaced (Y in S3), a forced toner consumption operation is performed (S4), and toner is replenished (S5). After the toner end is detected (Y in S6), a toner bottle replacement request is issued (S7). If the toner bottle 7 is replaced (Y in S8), a forced toner consumption operation is performed (S4), and toner replenishment is performed (S5). ).

FIG. 4 is a flowchart showing the operation at the time of toner near-end detection (No. 2). When the toner near end is detected (S1), a toner bottle replacement preparation request is issued (S2). If the toner bottle 7 is replaced (Y in S3), a forced toner consumption operation is performed (S4), and toner is replenished (S5). After the toner end is detected (Y in S6), a forced toner consumption operation is performed (S7), a toner bottle replacement request is issued (S8), and if the toner bottle 7 is replaced (Y in S9), toner supply is performed (S5). ).
In this example, since the apparatus shifts to the toner replenishing operation immediately after the toner bottle replacement and returns to the printable state, the return time from the toner bottle replacement at the toner end as an operator operation can be shortened.
The operation time of the forced toner consumption shown above can be managed by data related to the time required for discharging the residual toner obtained in advance through experiments or the like, and can also be managed based on the residual toner amount detected by the toner amount / density detection sensor 33. Similarly, the management is performed by any one of the management from the toner discharge amount by the image formation detected by the toner adhesion amount detection sensor 4 or a combination thereof. These threshold values can be set to arbitrary values.

1 is a configuration diagram of an image forming unit of an image forming apparatus according to an embodiment of the present invention. 6 is a flowchart illustrating an operation when toner end is detected. 7 is a flowchart (part 1) illustrating an operation when toner near-end is detected. 7 is a flowchart (part 2) illustrating an operation when toner near-end is detected.

Explanation of symbols

3 Developing device (developing device), 7 Toner bottle (toner supply means)

Claims (8)

  In a developing device comprising a toner replenishing device for supplying toner in the developing device and a control means, the control means is from the toner replenishing means replacement request to the start of toner replenishment after replacing the toner replenishing means. And a toner forcible consumption operation for forcibly consuming the remaining toner.   2. The developing device according to claim 1, further comprising a determining unit that determines a time and an end timing of the forced toner consumption operation.   3. The developing device according to claim 2, wherein the determining means is data obtained in advance.   3. The developing device according to claim 2, wherein the determining means is a toner amount / density detection sensor.   3. The developing device according to claim 2, wherein the time and end timing of the forced toner consumption operation are variable.   The developing device according to claim 1, wherein the toner forced consumption operation is performed by detecting a toner end.   2. The developing device according to claim 1, wherein the toner forcible consumption operation is performed by detecting a toner near end. An image forming apparatus comprising the developing device according to claim 1.

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