JPS63316072A - Electrophotographic recording device - Google Patents

Abstract

PURPOSE:To prevent the deterioration of image quality in forming an image after leaving a developer for a long time by stirring the developer every previously set specific time. CONSTITUTION:The titled device has at least an electrostatic latent image carrier 1, an exposure means 2 for executing an exposure according to an image signal and forming a latent image on the electrostatic latent image carrier 1, developing means 8a and 8b for developing the latent image, developer stirring means 8c and 8d for stirring the developer equipped in the developing means 8a and 8b and a control means for making the developer stirring means 8c and 8d actuate every previously set specific time while the action of forming the image is not executed and the developer stirring means 8c and 8d are made to be actuated every previously set specific time while the action of forming the image is not executed. namely, the developer is not left in a still state for a long time while the action of forming the image is not executed. By actuating the developer stirring means every previously set specific time, the developer is properly stirred so as to mix air with the developer. Thus, the density of amount of the developer can be prevented from increasing and the image quality is not deteriorated because electrostatic charging and stirring can be fully executed in forming the images after leaving the developer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to electrophotographic recording devices such as copying machines and printers.

2. Description of the Related Art Conventionally, in this type of apparatus, as is known, the developing means and/or the developer type means are generally in a non-operating state during the non-operation of image formation when the power is on and no operation command is input. , the developer was configured to be stationary.

Problems to be Solved by the Invention However, in such a configuration, the developer (toner) used generally has a small particle size, and the developer is left in a stationary state for a long time without performing an image forming operation. If this is done, there is a problem in that the bulk density of the developer becomes high and the developer is not sufficiently charged or stirred in the image forming operation after being left standing, resulting in a deterioration of image quality. The degree to which the bulk density of the developer increases varies depending on its particle size and the environment in which it is used. In particular, non-magnetic component developers have small particle sizes and are developed with one component without mixing carrier, If the developer absorbs moisture at high temperatures, the bulk density tends to increase.Therefore, one possible method is to keep the stirring means in constant operation even when image formation is not in progress.
In that case, problems arise in terms of noise, power consumption, etc., as well as problems such as deterioration of the developer and shortening of its life.

Means for solving the problems and the technical means of the present invention for solving the above problems are at least an electrostatic latent image carrier and a method for exposing the electrostatic latent image carrier to light according to an image signal. An exposure means for forming a latent image, a developing means for visualizing the latent image, a developer agitating means for stirring the developer provided in the developing means, and a device configured in advance during non-operation of image formation. and a control means for operating the developer agitating means at predetermined time intervals set in advance, and operating the developer agitation means at preset predetermined time intervals during non-operation of image formation.

action The effect of this technical means is as follows.

That is, instead of leaving the developer in a stationary state for a long time during non-operation of image formation, the developer stirring means is operated at preset intervals to agitate the developer at appropriate times for development. Air is mixed into the developer, which prevents the bulk density of the developer from increasing, and even during image forming operations after being left unused, sufficient charging and agitation can be performed without deteriorating image quality.
In addition, since the developer stirring means is not constantly operated during non-operation of image formation, there is no problem in terms of noise and power consumption, and since unnecessary stirring operations are not performed, the developer does not deteriorate. Hateful.

Examples Examples of the present invention will be described below. FIG. 1 is a conceptual diagram of an electrophotographic recording apparatus according to the present invention, which is equipped with means for operating a developer stirring means at predetermined time intervals during non-operation of image formation.

Reference numeral 1 denotes an electrostatic latent image carrier, which is formed by forming a film of a photoconductive material such as selenium on a cylinder made of aluminum or the like.

Incidentally, the electrostatic latent image carrier 1 may be an ordinary photoreceptor sheet coated with an organic photoconductor, etc., and 2 is a laser or LED.
An exposure means such as the above is driven by the driver circuit 3 to expose the electrostatic latent image carrier 1 dot by dot. 3 is a driver circuit that selectively drives the exposure means 2 to emit light or stop it in accordance with an image signal. 7 is a charger, and exposure means 2
The electrostatic latent image carrier 1 is charged to a certain surface potential before being exposed to light. A developer of each color is electrostatically attached to the electrostatic latent image to form a visible image (toner image). 8C58d is a developer stirring means, which is provided in the developing devices 8a and 8b, respectively.
In response to a drive command from the PU 5a, the developer is rotated by a motor (not shown) connected to each of them to agitate the developer and supply it to the developing rollers 8e and 8f. Developing rollers 8e and 8f hold the developer in the developing device in a thin layer and continuously supply it to the developing position. Reference numeral 9 denotes recording paper, and ordinary plain paper for copying machines is used. 10 is a transfer charger that transfers a visible image onto recording paper 9; 5a is a CPU, which inputs a signal (not shown) obtained in synchronization with the rotation of the electrostatic latent image carrier 1 to perform sequence control of the image forming process, and also starts and stops the timer counter 5b, or controls the timer counter 5b. The value is cleared, and the developer stirring means is operated through I10 baud) 5c in response to an interrupt signal from the timer counter 5b. 5b is a programmable timer counter, and CPU5
A predetermined time is set in advance by a, and when the count value reaches the predetermined time after activation, an interrupt signal is sent to the CPU 5a. 5c is an I10 board that operates predetermined equipment (not shown) according to predetermined timing based on data from the CPU 51L. 5d is ROM, CPU5a
It stores an image forming sequence program to be executed by the CPU, a predetermined time set in the timer counter 5b, and the like. Note that the predetermined time period set in the timer counter 5b until the developer stirring means is operated during the standby state is experimentally determined in advance depending on the developer to be used. 5e is a FLAM, which is temporarily used for block execution and calculation by the CPU 5a. Note that the CPU 5a, timer counter 5b, I10 port 5c% ROM 5d, and RAM 5e are connected by a pass line 4. 6a and 6b are motor drivers! 10 baud) When an operation signal is input from the CPU 5a through 5c, the developer stirring means 8c,
A motor (not shown) connected to 8d is driven.

The operation of the image forming sequence of this embodiment will be described below, but for the sake of clarity, images of two different colors are transferred to an electrostatic latent image carrier using negative-positive development (reversal development) used in laser printers, etc. An example will be described in which an experiment was conducted using a process in which the image is formed on the recording paper and then transferred all at once to the recording paper.

The electrostatic latent image carrier 1 is a selenium photoreceptor, and is rotated at a constant speed in the direction of R in FIG. 1 at a circumferential speed of about 100 mm/sec by a drive motor (not shown) at the start of the process. The charger 7 applies a positive direct current high voltage between the body and the core wire, and charges the entire surface of the electrostatic latent image carrier 1 by the generated corona. The driver circuit 3 selectively causes the exposure means 2 to emit or stop the exposure means 2 in accordance with an image signal to be formed using the color of the retained developer, thereby forming a negative electrostatic latent image (not shown). In this experiment, the exposure means 2 had a length of 210 mm (short side of A4 paper) and 240 mm.
A combination of a DPI LED array and a rod lens array with an aperture angle of 20° was used. Further, the developer stirring means 8c stirs the developer and supplies it to the developing roller 8e, and the supplied developer is charged to a developer charging means (not shown).
The developer is charged to a positive polarity, made into a thin layer by a developer thinning means (not shown), and held on the developing roller 8e. The developer is continuously supplied to the developing position by the rotation of the developing roller 8e, and is scattered onto the negative electrostatic latent image at the developing position.

In this way, the first color latent image is visualized.

Subsequently, the visible image of the first color is charged again by the charger 7, and the exposure means 2 charges the first color with an image signal corresponding to the image of the second color, that is, the color of the developer held in the developing device 8b. A second electrostatic latent image is formed by exposing the second electrostatic latent image to light, and the second electrostatic latent image is visualized by a developing device 8b holding a second color developer. In addition, at this time, the developer stirring means 8d and the developing roller 8
The operation is the same as when f is the first color. After a visible image (toner image) (not shown) of two different colors is formed on the electrostatic latent image carrier 1 in this way, a recording paper is 9 is fed into the electrostatic latent image carrier 1
A two-color toner image is transferred to the recording paper 9 at once by a corona generated by applying a negative direct current high voltage between the casing of the transfer charger 10 and the core wire at the portion in close contact with the core wire. The recording paper 9 is removed by a peeling means, a paper film feeding means, a fixing means (in both cases, unnecessary developer (toner) remaining on the electrostatic latent image bearing member 1 is removed by a cleaning means 11, and then used for the next image forming process). Be prepared.

Below, the means for operating the developer stirring means at predetermined time intervals during non-operation of image formation, which is the main part of the present invention, will be explained.

CPU5a is ROM5d, RAM5e
, r/0 baud) 5c along with timer counter 5b
is connected to the timer counter 5b by the pass line 4.
connected to start, stop, or clear the counter value. Further, the timer counter 5b is programmable and is set in advance as a predetermined time as a count value until an interrupt is issued to the CPU 5a. First, C.P.
The U5a sets the predetermined time read from the ROM 5d to the timer counter 5b, clears the count value, and then starts the timer counter 5b. The timer counter 5b is the CPU
Starts timer counting in response to the start command from 5a,
The cPU 5a counts up to a predetermined time, and when an operation command is input by the set predetermined time, the cPU 5a stops counting the timer counter 5b and executes the image forming sequence, but the count value does not change until the operation command is input. When the time reaches a predetermined time, the timer counter 5b interrupts the CPU 5a. And the interrupted cpub
a executes an interrupt program. That is! 10 sends operation commands to motor drivers 6a and 6b through boat 5c. The motor drivers 6a and 3b that receive the operation command drive respective motors (not shown) to rotate the developer stirring means.The CPU 5a also drives the I10 boat 5C.
After sending an operation command to the motor drivers 6a and 6b through the controller, the timer counter 5b is cleared to prepare for the next cycle of counting.

Next, the operation will be explained using FIG. 2. FIG. 2 is a flowchart illustrating the present invention in detail.

First, in step S1, interrupts are prohibited. Then, in step S2, the CPU 5a initializes the I10 port 5c and the counters and flags on the program.
The PU 5a sets the predetermined time read from the ROM 5d in the timer counter 5b. In step S4, the CPU 5a clears the timer counter 5b, and in step S5, activates the timer counter 5b to start counting. After starting the timer counter 5b, an interrupt is permitted in step S6 in preparation for an interrupt from the timer counter 5b. In step S7, the CPU 5a monitors the presence or absence of an operation command and enters a so-called standby state for image forming operation.When an operation command is input, interrupts are prohibited again in step S9, and the process proceeds to step S10, where the timer counter 5b starts counting. Then, in step S11, an image forming sequence is executed. When the image forming sequence is completed, the process returns to step S4 and after clearing the timer counter 5b, it is activated and enters the standby state again.

On the other hand, the timer counter 5a continues to count up in a standby state in which no operation command is manually input to the CPU 5a, and when a preset predetermined time is reached, an interrupt is issued to the CPU 5a. Then, when an interrupt is issued in step S8, the CPU 5a executes the operation of the developer agitating means, which is an interrupt program, in step S12. That is, an operation command is output to the motor driver (3a, 6b) through the I10 boat 5C, and the motor is driven to rotate the developer stirring means 8c, 8d.Then, after the developer stirring means 8a, 8b rotates and stirs the developer. , returns to step S4, clears the timer counter 5b, and starts counting for the next cycle.In other words, when the predetermined time set in the timer counter 5b elapses in a standby state in which no operation command is input, the developer stirring means 8a, 8b is operated to agitate the developer and prevent the bulk density of the developer from increasing due to being left in a stationary state for a long time.If the standby state continues, the predetermined time set in the timer counter 5b is activated. The developer stirring means 8a and 8b are operated periodically.

In this embodiment, there is only one type of predetermined time stored in the ROM 5d and set in the timer counter 5b, but the temperature sensor, humidity sensor, and their outputs t! :The CPU 5a is equipped with an A/D converter for A/D conversion, and further stores a plurality of predetermined times determined experimentally in advance in the ROM 5d, and outputs the A/D converted temperature sensor and humidity sensor. By selecting a predetermined time according to the temperature and humidity at that time from among a plurality of predetermined times read and stored in the ROM 5d and setting it in the timer counter 5b, the developer can be It becomes possible to change the predetermined time period during which the stirring means is operated. Note that if a predetermined period of time elapses without an operation command being input during the image forming nose operation, after operating the developer stirring means,
By reading the temperature and humidity at that time again and resetting the predetermined time accordingly, it is possible to cope with the changing surrounding environment even during non-operation of image formation.

Further, in this embodiment, an example of negative-positive development (reversal development) has been described, but it is clear that similar effects can be obtained with a developer used in positive-positive development (regular development).

The present invention has been described above with reference to embodiments, but it is not limited to those described in the above examples, and includes, for example, an image device that forms a monochromatic image, an image device that forms an image of two or more colors, etc. It goes without saying that the present invention can be effectively applied to

Effects of the Invention The present invention provides at least an electrostatic latent image carrier, an exposure means for forming a latent image on the electrostatic latent image carrier according to an image signal, and a developer (toner) for electrostatically applying a developer (toner) to the latent image. A developing device for electrically depositing the developer to form a visible image, a developer stirring means provided in the developing device for stirring the developer, and a predetermined developer stirring means set in advance during non-operation of image formation. It has a means for operating the developer stirring means every time, and instead of leaving the developer in a stationary state for a long time even when image formation is not in operation, the developer is stirred at every preset predetermined time. This prevents the bulk density of the developer from increasing and allows the developer to be sufficiently charged and stirred, thereby making it possible to prevent image quality from deteriorating even in image formation after being left for a long time.

Furthermore, it is possible to change the predetermined time for operating the developer stirring means according to the surrounding environment. In environments where the bulk density is difficult to increase, by lengthening the cycle and reducing the number of times of stirring, it is possible to save power consumption and suppress deterioration of the developer.

Further, since the developer agitating means is not constantly operated during non-operation of image formation, it has great practical effects, such as being able to suppress the shortening of the lifespan due to deterioration of the developer.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of an electrophotographic recording apparatus according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of the apparatus. 1... Electrostatic latent image carrier, 2... Exposure means, 3...
Driver circuit, 4...pass line, 5a...CPU
, 5b... timer counter, 5c... I10
Boat, 5d-・FLOM, 5e...RAM, 6
a, 6b...Motor driver, 7...Charger, 8a
, 8b...Developer, 8C58d...Developer type means, 9...Recording paper, 10...Transfer charger, 11...
Name of agent for cleaning means Patent attorney Toshio Nakao Haka 1 person 1 ・-Evaluation row image carrier Button, island-Motor de Diva 2-Tip + stage 7...Obi TA 3-Driver circuit sa, sb '-Rikagai 4-・
Pass line 8cFJ, J-31i image cutting means 5a -
CPU 8e, 8f -' rjL110-ra 5b-timer counter 9-R paper 5C・-rlo, I? -t +0
-1 turn 2 leather ta sea RO/'f
If -Cleaning means 5e-RAr'+ Fig. 1

Claims (4)

[Claims] (1) At least an electrostatic latent image bearing member, an exposing means for exposing to light according to an image signal to form a latent image on the electrostatic latent image bearing member, and a developing means for visualizing the latent image; It has a developer stirring means for stirring the developer provided in the developing means, and a control means for operating the developer stirring means at predetermined time intervals during non-operation of image formation. An electrophotographic recording apparatus configured to operate a developer stirring means at predetermined time intervals during operation. (2) The control means includes at least a CPU, a timer counter, and a ROM, and the predetermined time stored in the ROM is controlled by the CPU.
is read and set in the timer counter, the CPU starts the timer counter, and when the count value of the timer counter reaches a predetermined time, the timer counter interrupts the CPU, and in the interrupt program, the CPU operates the developer stirring means. An electrophotographic recording apparatus according to claim 1, wherein the electrophotographic recording apparatus is configured to output a signal that causes a signal to be generated. (3) The electrophotographic recording apparatus according to claim 1, wherein the developer is a non-magnetic one-component developer. (4) The electrophotographic recording apparatus according to claim 1, wherein the developing means for visualizing the latent image includes a plurality of developing means each containing a developer of a different color.