JPH04313770A - Method for controlling action of image recorder - Google Patents

Abstract

PURPOSE:To prevent a black band from occurring because toner adheres to a photosensitive body or carrier from adhering at the time of starting and stopping image recording actions in an image recorder in which a reversal developing system developing device is used. CONSTITUTION:This action control method is as follows. At the time of starting the image recording actions, a main motor 16 for driving the photosensitive body 10 is driven and then developing bias is impressed on a developing roll 17 as soon as the photosensitive body 10 is electrostatically charged by an electrostatic charger 11. Thereafter, a motor 18 for developing device which drives the developing roll 17 is driven so as to make the developing device 13 in a development feasible state. At the time of stopping the image recording actions, the motor 18 is stopped to make the device 13 in a development unfeasible state, then the electrostatic charging by the electrostatic charger 11 is stopped. Thereafter, the main motor 16 is stopped and the photosensitive body 10 is stopped. At the time of starting and stopping the image recording actions, the area of the photosensitive body 10 which is not electrostatically charged is prevented from being developed by the developing device 13, and the black band is prevented from occurring because the toner adheres to the photosensitive body 10 or the carrier is prevented from adhering.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operations of a photoreceptor, a charger, a developer, etc. in an image recording apparatus such as an electrophotographic copying machine or a printer when starting and stopping an image recording operation.

0002

2. Description of the Related Art In order to facilitate operation control in a normal image recording apparatus, a photoreceptor and a developing roll of a developing device are simultaneously driven at the start of an image recording operation, and a charger is turned on a little later to record an image. When the operation is stopped, the charger is turned off, and then the photoreceptor and the developing roll of the developing machine are stopped. In this way, the photoreceptor and the developing roll can be driven and stopped at the same time, making it easier to control the operation and making it possible to use a common drive system for both.

0003

Problems to be Solved by the Invention There is a developing machine called a reversal developing system in which the photoreceptor is charged and the toner is charged with the same polarity. For example, as shown in FIG. 1(a), the photoreceptor 1 is charged to -700V with the charger 2, and as shown in FIG. As shown in 1(c), a developing bias of -500V of the same polarity lower than the potential of the photoreceptor 1 is applied to the developing roll 4 of the developing device 3, and the image area is set at a higher potential than the toner 5, and the toner 5 is applied to the image area. A developing machine using a reversal developing method for adhesion is known. In addition, in FIG. 1(c), toner 5 is -5
00, and the potential of the photoreceptor 1 other than the image area is -700V.
Therefore, the toner 5 does not adhere to areas other than the image area of the photoreceptor 1. In an image recording apparatus using a reversal development type developer as described above, if the operation control described above is performed at the start and stop of the image recording operation, toner may adhere to the photoconductor and cause a black band, or the carrier may may adhere. For example, when starting an image recording operation or stopping an image recording operation,
As shown in the figure, the area 6 that is not charged by the charger 2 is the developing device 3.
Since the electric potential of the area 6 is zero, the electric potential of the area 6 becomes higher than that of the toner 5, and the toner 5 adheres thereto, causing a black band or carriers to adhere.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for controlling the operation of an image recording apparatus that can solve the above-mentioned problems.

[Means for solving the problem] At the start of an image recording operation, the photoreceptor is driven and then charged with a charger to make the developing machine ready for development, and at the start of the image recording operation, the developing machine is put in a non-developing state and then charged. An operation control method that stops the photoreceptor by stopping charging by the device.

[Function] When the image recording operation is started or stopped, the uncharged area of the photoreceptor will not be developed by the developing machine.

[0005]

[Example of implementation] As shown in FIG.
3. A transfer device 14, a cleaner 15, etc. are arranged in sequence, the photoreceptor 10 is driven by a main motor 16, the developing roll 17 is driven by a developing machine motor 18, and a developing bias is applied by a developing bias power source 19. The charger 11 is connected to a high-voltage power source 20, and their operation is controlled by a controller 21. Paper is fed to the transfer device 14 from a paper feed mechanism 22 along a paper conveyance path 23, and the paper is A sensor 24 is provided at a pre-registration position on the paper transport path 23, and a detection signal from the sensor 24 is sent to the controller 21.

Next, the operation will be explained. When a recording operation start signal is input to the controller 21 from the print button 25, the main motor 16 is driven to rotate the photoreceptor 10, and after a preset time has elapsed, a signal is sent to the high voltage power supply 20 and the developing bias power supply 19. At the same time, a bias is applied to the developing roll 17. At the same time, the optical system 12 irradiates and exposes the surface of the photoreceptor 10 with the original image to form an electrostatic latent image. After a predetermined period of time has elapsed, for example, when the leading edge of the paper is detected by the pre-registration sensor 24, a signal is output to the developing machine motor 18 to rotate the developing roll 17 to enable development. As a result, a developing operation is performed after the charged area of the photoreceptor 10 reaches the developing device 13, so that toner may adhere to areas other than the electrostatic latent image on the photoreceptor 10, resulting in black bands, and carrier will not stick to the surface. When a predetermined number of image recording operations are completed, first the developing machine motor 18 is stopped to stop the developing roller 17, then a signal is output to the high voltage power supply 20 to stop the charging by the charger 11, and after a while, the developing roller 17 is stopped. A signal is output to the bias power supply 19 to stop the application of the developing bias, and finally the main motor 16 is stopped to stop the photoreceptor 10. As a result, when the uncharged area of the photoreceptor 10 passes through the developer 13, the developer 13 is in a state where it cannot develop, so toner may adhere to the photoreceptor 10 and cause a black band, or the carrier may Will not stick. The above operation timing is as shown in FIG.

[0007]

Effects of the Invention: Since the uncharged area of the photoconductor 10 is not developed by the developing device 13 at the start and stop of the image recording operation, toner may adhere to the photoconductor 10 and cause a black band, and carrier It can prevent the adhesion of

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a reversal development method.

FIG. 2 is a diagram illustrating a conventional problem.

FIG. 3 is a schematic explanatory diagram showing an example of an image recording apparatus that implements the method of the present invention.

FIG. 4 is a chart showing operation timing.

[Explanation of symbols]

10 photoreceptor, 11 charger, 13 developer, 1
6 main motor, 17 developing roll, 18 developing unit motor, 19 developing bias power supply, 20 high voltage power supply, 21 controller.

Claims (1)

[Claims] 1. In an image recording apparatus equipped with a developing device of a reversal development type in which the charging of the photoreceptor 10 by the charger 11 and the charging of the toner in the developing device 13 are of the same polarity, the photoreceptor 10 is turned off at the start of the image recording operation. After driving, the charger 11 charges the photoreceptor, and then the developing device 13 becomes ready for development.When the image recording operation is stopped, the developing device 13 is put in a non-developing state, and then charging by the charger 11 is stopped, and then the photoreceptor is charged. 1. A method for controlling the operation of an image recording apparatus, characterized in that the operation of the image recording apparatus is stopped.