JPH0355578A - Developing device for electrophotography - Google Patents

Abstract

PURPOSE:To prevent print quality from being deteriorated owing to the deterioration of a developer by displaying the need to replace a developer with an instruction from a microprocessor circuit. CONSTITUTION:The time of the rotation of a developing device motor 2 is integrated by an integrating circuit 3, which outputs the integrated time to the microprocessor circuit 6 when the integrated time reaches a constant value. The microprocessor circuit 6 rewrites data in a nonvolatile RAM circuit 4 into new data at each time according to the sent data. The replacement period of the developer is recorded in a ROM circuit 5 in the form of the driving time of the developing device motor 2. The microprocessor circuit 6 compares the data in the nonvolatile RAM circuit 4 with the value of the data recorded previously in the ROM circuit 5 and displays the need to replace the developer by using a display device 54 when the data value in the nonvolatile RAM circuit 4 exceeds the data value in the ROM circuit 5. Consequently, the accurate replacement period is grasped and the print quality is prevented from being deteriorated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrophotographic developing device, and is particularly suitable for development using a two-component development method in which two predetermined developers are used in combination. The present invention relates to an electrophotographic developing device.

[Conventional technology]

It has been conventionally known that in this type of electrophotographic developing device, the charging characteristics of the developer decrease in proportion to the stirring time of the developer, and the developer deteriorates. If the developer is used while it has deteriorated, printing quality will be adversely affected, so it is required to replace the developer with a new one before deterioration occurs.

In order to know when to replace the developer, the stirring time is used as a criterion for determining the deterioration of the developer, and if the predetermined time is exceeded, the developer must be replaced with a new one. However, in general, the number of sheets of developed paper is used as a criterion for determining deterioration, instead of the stirring time, and the time for replacement is determined by considering that the deterioration of the developer progresses in proportion to the number of sheets of paper.

Next, FIG. 2 shows a conventional example.

In the conventional example shown in FIG. 2, the transferred paper (not shown) is conveyed and... A paper traveling section 50 that emits a signal each time a sheet of paper is conveyed, and based on this signal,
*Non-volatile RAM that constantly records the number of sheets sent
A circuit 51 and a ROM circuit 52 and a ROM circuit 52, which records the preset developer replacement period using the number of standard sheets
A macroprocessor circuit 53 compares the set number of sheets recorded in the circuit 52 with the number of transported sheets recorded in the nonvolatile RAM circuit 51, and a command from the microprocessor circuit 53 determines when to replace the developer. It has a display section 54 that displays that the time limit has been reached, and an input section 55 that inputs a command to initialize the memory of the nonvolatile RAM circuit 51 via the microprocessor circuit 53. Next, the operation will be explained.

The paper running unit 50 sends a signal to the microprocessor circuit 53 every time one page of standard paper is printed.

The microprocessor circuit 53 rewrites the data in the nonvolatile RAM circuit 5l every time the signal is input. R.O.
The memory of the M circuit 52 records the developer replacement timing as a value converted to the number of standard sheets of paper run. The microprocessor circuit 53 has a nonvolatile RAM circuit 51 and R
When the data values of the OM circuit 52 are compared and the data of the nonvolatile RAM circuit 51 becomes larger than the value recorded in the ROM circuit 52, the display section 54 indicates that it is time to replace the developer. to be displayed. The operator replaces the developer while looking at the display on the display unit 54.

Thereafter, when an input indicating that the developer has been replaced is inputted from the input section 55, the microprocessor clears the memory of the nonvolatile RAM circuit 5l and prepares for determining the next developer replacement time.

[Problems to be Solved by the Invention] However, in the above conventional example, since the judgment is made on the assumption that the deterioration of the developer is proportional to the number of sheets of paper that has been run, the printing interval of the paper is determined due to the print data editing. If the developing device rotates and prepares for printing during that time, the number of sheets of paper that has traveled is not added up, even though the developer is being agitated and is gradually deteriorating. This leads to deterioration of the product and it is continued to be used even after the replacement period has passed. This has caused the inconvenience of deteriorating print quality.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic developing device that improves the disadvantages seen in the conventional example and prevents deterioration in print quality due to developer deterioration. [Means for Solving the Problems] In the present invention, a developing device containing a developer, a developing device motor that stirs the developer in this developing device, and a predetermined amount of time are calculated by integrating the driving time of this developing device motor. and an integration circuit that issues a signal when the time of . Furthermore, there is a nonvolatile RAM circuit that records the driving time of the developer motor as needed, a ROM circuit that stores the set time that is set in advance as the developer replacement time, and a ROM circuit that stores the set time that is set in advance as the developer replacement time. The microprocessor circuit compares the current setting time with the driving time of the developer motor recorded in the nonvolatile RAM circuit, and writes the signal generated by the integration circuit into the nonvolatile RAM circuit. A display section that displays when the developer is due for replacement based on a command from the microprocessor circuit, and an input section that inputs a command to initialize the memory of the nonvolatile RAM circuit via the microprocessor circuit. We have adopted the method of having This is intended to achieve the above-mentioned purpose.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described based on FIG.

Here, the same reference numerals will be used for the same structures or members as in the prior art described above.

In the embodiment shown in FIG. 1, the developing device 1 containing developer, the developing device motor 2 that stirs the developer in this developing device 1, and the driving time of this developing device motor 2 are integrated. It also includes a non-volatile RAM circuit 4 which records the driving time of the developer motor 2 as needed, and a non-volatile RAM circuit 4 which outputs a signal when the developer motor 2 reaches a predetermined time. A ROM circuit 5 that stores the set time set as Integration circuit 3
The microprocessor circuit 6 has a macro processor circuit 6 that writes signals generated by the microprocessor into the nonvolatile RAM circuit 4. Then, a command from the microprocessor circuit 6 is inputted to the display section 54 to display that the developer is due for replacement, and a command to initialize the memory of the nonvolatile RAM circuit 4 via the microprocessor circuit 6. It has an input section 55.

Next, the operation will be explained.

An electrostatic latent image created on the surface of a photoreceptor by an electrophotographic printing device is transferred onto printing paper by a transfer device, and the printing paper is conveyed and transferred to a developing device.

A developing device l in the developing device contains two types of developer, and a developing device motor 2 stirs the developer to prepare for development. The developer motor 2 transmits the rotating time to the integration circuit 3, and when the integration time accumulated by the integration circuit 3 reaches a certain value, the integration circuit 3 outputs the integration time to the microprocessor circuit 6. The next rotation time of the developing device motor 2 is newly measured. The integration circuit 3 repeatedly performs this operation. The microprocessor circuit 6 rewrites the data in the nonvolatile RAM circuit 4 each time based on the sent data. In the ROM circuit 5, the developer replacement timing is expressed in terms of the driving time of the developer motor 2 and is recorded in advance. The microprocessor circuit 6 is a non-volatile RAM
The data in the circuit 4 is compared with the data value recorded in advance in the ROM circuit 5, and when the data value in the nonvolatile RAM circuit 4 exceeds the data value in the ROM circuit 5, it is determined that it is time to replace the developer. The display unit 54 is used to display that the target has been reached. The operator replaces the developer with new one according to this display. When the replacement is completed, the operator inputs a message to that effect from the input section 55, clears the memory of the nonvolatile RAM circuit 4, and prepares for detection of the next replacement time.

[Effects of the Invention] As explained above, the present invention is equipped with an integration circuit that integrates the driving time of the developer motor that stirs the developer in the developer and issues a signal when a predetermined time is reached. At the same time, the deterioration of the developer is determined based on the driving time of the developer motor. Therefore, the stirring time of the developer can be known extremely accurately, and the state of deterioration of the developer, which is said to be proportional to the stirring time, can be accurately grasped. This makes it possible to accurately determine when to replace the developer, prevent deterioration in print quality, and eliminate wasteful developer replacement, reducing running costs.This is an unprecedented electrophotographic developing device. can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 1...Developer, 2...Developer motor,
3...Integrator circuit, 4...Nonvolatile RA
M circuit, 5...ROM circuit, 6...Microprocessor circuit, 54...Display section, 55
...Input section.

Claims (1)

[Claims] (1) A developing device that stores developer, a developing device motor that stirs the developer in this developing device, and an integration that issues a signal when the driving time of this developing device motor is integrated and reaches a predetermined time. a non-volatile RAM circuit that records the driving time of the developer motor as needed, a ROM circuit that stores a set time that is set in advance as the developer replacement time, and this RO.
The set time recorded in the M circuit and the non-volatile R
a macroprocessor circuit that compares the driving time of the developer motor recorded in the AM circuit and writes the signal generated by the integration circuit into the nonvolatile RAM circuit; A device for electrophotography comprising: a display unit that displays when the developer is due for replacement according to a command; and an input unit that inputs a command to initialize the memory of the nonvolatile RAM circuit via the microprocessor circuit. Developing device.