JPS61194462A - Print controller - Google Patents

Abstract

PURPOSE:To improve the contactness of a form with a photosensitive drum and to improve transfer efficiency by stopping applying a voltage to a separating corotron a specific time after the front end of the form leaves the photosensitive drum. CONSTITUTION:A transfer corotron 8, the separating corotron 9, and form end detecting means 6 and 11 are arranged at the transfer part of a laser beam printer 9. Then, when the detecting means 11 detects the front end of the printing form 5 after an image is transferred to the printing form 5 through the transfer corotron 5, the voltage is still applied to the separating corotron 9 before, but the voltage application is stopped. Consequently, the contactness of the form 5 with the photosensitive drum 1 is increased and the toner image on the drum is transferred efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing control method for equipment having a peeling corotron for peeling paper from a photosensitive drum, such as a cut paper laser beam printer using an electrophotographic method.

FIG. 1 shows a block diagram of the photosensitive drum circumference of a cut paper laser beam printer. In the figure, 1 is a photosensitive drum rotating at a constant circumferential speed in the direction of the arrow in the figure, 2 is a laser beam that exposes the photosensitive drum 1, and 3 is a toner that adheres to the latent image formed on the photosensitive drum 1. 4 is a charging corotron for charging the photosensitive drum 1; 5 is a printing pile means A; 7 is a paper feed roller that feeds the printing paper 5 at a speed equal to the circumferential speed of the photosensitive drum 1; 8 is a transfer corotron that transfers the toner on the photosensitive drum 1 developed by the developing device 3 onto the printing paper 5, 9 is a peeling corotron that peels off the printing paper 5 that is in close contact with the photosensitive drum 1, and 1O is a post-transfer corotron. a paper conveyance device that conveys the paper of
A paper edge detection means B1p detects the edge of the printing paper 5 peeled off from the photosensitive drum 1 by the peeling corotron 9, and a cleaner 13 cleans the toner remaining on the photosensitive drum 1 after transfer. Each device is shown.

Here, printing is performed as the photosensitive drum l rotates, charging, developing,
It is performed through a series of operations of transfer, peeling, and cleaning□.

In a cut paper laser beam printer, the charged photosensitive drum 1 and the printing paper 5 are brought into close contact with each other due to static electricity, so it is necessary to provide special means for separating the photosensitive drum 1 and the printing paper. As a means of this, exfoliation,
There is a method of mechanically peeling the printing paper 5 from the photosensitive drum 1 using a peeling tape or the like. When using this method,
Since it is necessary to bring a nail or tape into contact with a portion of the paper, there is a drawback that printing cannot be performed on that portion. On the other hand, when the peeling corotron 9 is used, the above-mentioned unprintable areas are eliminated, but there is a drawback that the adhesion between the photosensitive drum and the printing paper 5 is weakened and the transfer efficiency is reduced. Particularly in a small device, when the transfer corotron 8 and the peeling corotron 9 are mounted close to each other, the photosensitive drum 1 and the printing paper 5 may separate from each other at the end of the printing paper 5 due to the rigidity and curling of the printing paper 5. There were times when the image could not be transferred.

FIG. 2 shows a timing chart when a conventional peeling corotron is used. When printing is started, a voltage is first applied to the charging corotron 4 and the peeling corotron 9.

After a certain period of time after the leading edge of the printing paper 5 is detected by the paper edge detection means A, when the leading edge of the printing paper 5 is about to reach the photosensitive drum 1, a voltage is applied to the transfer corotron 8.

Next, when the printing paper 5 separates from the photosensitive drum 1, the voltage application to the transfer corotron 8 is stopped, but the charging corotron 4 and the peeling corotron 9 even have grooves to which voltage is applied during printing. As described above, this causes poor adhesion between the printing paper and the photosensitive drum, which in turn causes a drop in transfer efficiency.

The present invention eliminates the above-described drawbacks of the prior art and improves the efficiency of transferring toner developed on a photosensitive drum to paper.

The present invention focuses on the fact that if the peeling corotron does not operate, the paper and the photosensitive drum will stick together due to static electricity, and after the leading edge of the paper is peeled off from the photosensitive drum, the voltage application to the peeling corotron is stopped and the paper is This improves the adhesion of the photosensitive drum to the photosensitive drum and improves the transfer efficiency.

An example in which the present invention is implemented in a cut paper laser beam printer will be described.

FIG. 3 shows a timing chart of the embodiment.

In the cut paper laser beam printer of this embodiment, printing is started, and after a certain period of time after the leading edge of the printing paper 5 reaches the paper edge detection means A6, when the leading edge of the printing paper 5 reaches the photosensitive drum 1, the transfer corotron 8 and peeling corotron 9 voltages are applied. Next, the printing paper 5 is brought into close contact with the photosensitive drum 1, and the toner developed on the photosensitive drum is transferred to the transfer corotron 8. Next, the sheet is peeled off by the peeling corotron 9 and from the photosensitive drum 1, and reaches the paper transport device ship. Here, when the printing paper 5 is not wrapped around the photosensitive drum 1 and the paper can be transported by the paper transport device 10,
Stop applying voltage to the peeling corotron 9. In this embodiment, when the leading edge of the printing paper 5 reaches the paper edge detection means Bll in the paper transport device p, the voltage application to the peeling corotron 9 is stopped. As a result, the adhesion between the photosensitive drum 1 and the printing paper 5 is strong, and the toner developed on the photosensitive drum 1 can be efficiently transferred. In particular, the trailing edge of the printing paper 5 is also brought into close contact with the photosensitive drum 1 so that printing can be performed without causing transfer defects.

According to the present invention, since the adhesion between the photosensitive drum and the printing paper is improved, the toner developed on the photosensitive drum can be efficiently transferred to the printing paper.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the photosensitive drum and its surroundings in a cut paper laser beam printer, and FIG. 2 is a timing chart of a conventional example. FIG. 3 is a timing chart of one embodiment of the present invention. In the figure, 1 is a photosensitive drum, 4 is a charged corotron, and 5 is a photosensitive drum.
8 is a printing paper, 8 is a transfer corotron, 9 is a peeling corotron, and B is a printing control device.

Claims (1)

[Claims] An electrophotographic method is used that includes a photosensitive drum that rotates at a constant circumferential speed, a transfer corotron that transfers the toner developed on the photosensitive drum onto paper, and a peeling corotron that separates the paper that is in close contact with the photosensitive drum. In a cut paper printing device, after a leading edge of the paper is peeled off from the photosensitive drum, voltage application to the peeling corotron is stopped after a predetermined period of time has elapsed, and the transfer efficiency of toner developed on the photosensitive drum is improved. A printing control method featuring: