JPH02178148A - Print positioning control method - Google Patents

Abstract

PURPOSE:To make highly accurate registration securable at high speed conveyance even in case of stopping a sheet temporarily for being on standby as well as to simplify a memory circuit in structure by controlling a conveying speed at time of a startup according to the timing of print positioning. CONSTITUTION:In print positioning control over a printer which conveys a sheet in a state of being allowed of its sliding again and transfers and fixes a toner image after a sheet of paper 2 conveyed out of a hopper 16 is once stopped by a resist mechanism 9 and registration with the toner image on a sensitizer is carried out, the resist mechanism 9, which stops the paper 2 once through detection by an optical sensor 10 at a tip of the paper 2 and reopens the conveyance at timing congruous with the registration, is rotated at a lower startup speed than a startup conveying speed of the paper 2 via a timing belt 8, guiding the paper 2, and then it is constituted so as to be opened from the paper 2 after being reached to the constant conveying speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to positioning control between a toner image on a photoreceptor and paper in a printer, and in particular, print positioning control suitable for improving conveyance accuracy at high speeds. Regarding the method.

[Conventional technology]

In the conventional printing positioning control method,
As described in Japanese Patent No. 1.90144, opening and closing of the registration gate (registration mechanism) was simply performed by on/off control.

Generally, high-speed printers (high-speed LBP) employ a method in which printing information is stored in a memory and is printed on a photoreceptor in accordance with the timing of printing paper. This method requires a large-capacity memory in the electronic circuit section, which inevitably increases costs. Therefore, it is necessary to adopt a method for transporting paper in accordance with the font development of print information. However, when aligning the toner image on the photoreceptor with the paper, the paper must be temporarily stopped by a registration mechanism, and there was no registration mechanism that could transport and stop the paper at high speed and with high precision.

[Problem to be solved by the invention]

Conventional print positioning control methods do not take into account the unstable behavior of the paper when it leaves the registration mechanism, and there is a problem in that the registration performance deteriorates in the case of high-speed conveyance.

An object of the present invention is to provide a print positioning control method that ensures highly accurate registration performance even when paper is conveyed at high speed.

[Means to solve the problem]

In order to achieve the above object, the print positioning control method according to the present invention separates and conveys a sheet of paper from a hopper,
A printer that uses a registration mechanism to temporarily stop the paper to align it with the toner image on the photoreceptor, then conveys the paper again while allowing slippage, transfers the toner image, and fixes the toner image on the paper. In the print positioning control method of the registration mechanism, the registration mechanism, which temporarily stops the paper upon detection of the leading edge of the paper and resumes conveyance at the timing when alignment is matched, is rotated at a rising speed lower than the rising conveyance speed of the paper. It is configured to guide the paper and release it from the paper after the paper reaches a certain conveyance speed.

[Effect]

According to the print positioning control method of the present invention, the registration mechanism operates to release the paper by moving at an acceleration lower than the rising acceleration of the paper.

As a result, the leading edge of the paper is regulated and braked until it reaches a certain conveyance speed, so the conveyance speed when the paper rises, which has the greatest variation, is the timing for print alignment. controlled accordingly.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 7.

As shown in FIG.
After the paper 2 is temporarily stopped by the registration mechanism (registration gate) 9 and aligned with the toner image on the photoreceptor (not shown), the paper 2 is transported again in a state where slipping is allowed. In a printing positioning control method of a registration mechanism 9 of a printer that transports a toner image and fixes the toner image on a paper 2, the paper 2 is temporarily stopped by detection by an optical sensor 10 at the leading edge of the paper 2, and the paper 2 is aligned. The registration mechanism 9, which restarts the conveyance at the same timing, is rotated via the timing belt 8 at a rising speed lower than the rising conveying speed of the paper 2 to guide the sheet 2 until the sheet 2 reaches a certain conveying speed. After that, the paper 2 is released.

To explain in more detail, the sheets 2 separated one by one from the hopper 16 are sent to the registration gate (registration mechanism) 9 by the conveyor belt 1. Note that a plurality of conveyor belts 1 are arranged in parallel on drive shafts 3 disposed perpendicular to the conveyance direction, and timing belts 8 . A plurality of register storage giant gates 9 and conveyance rollers 5 are arranged in parallel on respective drive shafts 7 and 4, and drive shafts 3, 4 and 7 are pivotally supported by a support plate 11.

The registration gate 9 is triggered by a signal output by the optical sensor 10 when the leading edge of the paper 2 is detected.

The registration gate 9 releases the paper 2 in response to a signal output from a central processing unit (not shown) as a trigger. The paper 2 is accelerated by the conveying force (frictional force) of the conveying belt 1 and is held between the conveying rollers 5 .

Next, the operation of the registration gate 9 will be explained with reference to FIGS. 2 to 6.

As shown in FIG.
0 is separated one by one by a vacuum separation device composed of a suction chamber 13, a separation belt 14, and a pulley 15 for driving the separation belt, and sent to the conveyor belt 1 on the downstream side.

The registration gate 9 operates using a signal when the leading edge of the paper 2 crosses the optical sensor 10 as a trigger. The registration gate 9 consists of a plurality of registration gates 9 and 9A that are fixed to the timing belt 8 at respective positions dividing the circumference of the belt into approximately two equal parts, and are arranged in parallel as described above. It operates via a north motion source (not shown). Note that the operation will be explained below using the registration gate 9 as a representative.

The speed V of the registration gate 9 is controlled over time t in the speed pattern shown in solid lines in FIG.

First, using the signal from the optical sensor 10 as a trigger, the registration gate 9 is accelerated to a speed equal to the transport speed υ of the transport belt 1. In this section from 0 to a, the registration gate 9 must be located on the downstream side of the leading edge of the paper 2.

After that, the registration gate 9 decelerates,
It collides with the leading edge of paper 2 in section β. Paper 2 is guided to registration gate 9.

At point 0, it stops in the state shown in FIG.

In the process of decelerating the paper 2, the paper M on the conveyor belt 1
2, slippage is allowed.

The registration gate 9 is accelerated at point d in response to an output signal from the central processing unit, thereby opening the paper 2 as shown in FIG.

At this time, as shown in FIG. 6, the paper 2 tries to accelerate due to the conveying force (frictional force) of the conveying belt 1, but -
As shown by the dashed line, the acceleration behavior is not stable. Therefore, if the sheet 2 is held between the conveyance rollers 5 at point Q, the area A of the diagonally shaded portion is the conveyance distance of the sheet 2 from the stop position of the registration gate 9 to the conveyance roller 5. The time t required at this time is d-0 time.

However, at time d-0, there is a large variation in speed due to slipping of the paper 2, so the alignment accuracy between the paper 2 and the toner image on the photoreceptor (not shown) becomes insufficient.

Therefore, FIG. 7 shows a speed pattern in which the registration gate 9 according to this embodiment is raised at an acceleration lower than the rising acceleration of the sheet 2. In FIG.

Using the print timing signal output from the central processing unit as a trigger, the registration gate 9 is gradually raised in the first acceleration region α (between d and P), and suddenly raised at point P. It has a second acceleration region α2 (between P''e).

The movement of the paper 2 with respect to the speed pattern of the registration gate 9 at this time is shown in FIG.

The paper 2 tries to rise at an acceleration higher than the rise acceleration of the registration gate 9, but the paper 2 tries to rise at an acceleration higher than the rise acceleration of the registration gate 9,
In this case, the movement of the paper 2 is controlled by the operation of the registration gate 9.

Then, when the speed of the paper 2 reaches point P, the registration gate 9 changes to the second acceleration range α2, and the relative speed difference between the paper 2 and the conveyance speed of the conveyor belt 1 decreases, so that the paper 2 runs on the run-up. As shown between R and R, the paper accelerates and is transported in a relatively stable manner, and is held between the transport rollers 5. Therefore.

Since the dR time is always stable, the paper 2 and the toner image on the photoreceptor (not shown) are aligned with high precision.

〔Effect of the invention〕

According to the print positioning control method of the present invention, by rotating the registration mechanism at a rising speed lower than the rising transport speed of the paper, high-accuracy registration can be achieved even when the paper is temporarily stopped and put on standby. Since the memory circuit for storing high-speed printing information can be simplified, a printer such as a high-speed LBP can be realized at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of one embodiment of the present invention, and FIGS.
This figure is a sectional view of FIG. 1 showing the operation of the registration mechanism, and FIGS. 6 and 7 are graphs showing the relationship between time t and the speed of the registration mechanism and paper. DESCRIPTION OF SYMBOLS 1... Conveyance belt, 2... Paper, 5... Conveyance roller, 9... Registration gate (registration (1)
). 10... Optical sensor 16... Hopper.

Claims (1)

[Claims] 1. Separate a sheet of paper from the hopper, transport it, pause the paper using the registration mechanism to align it with the toner image on the photoreceptor, and then transport the paper again in a state where slipping is allowed. In the print positioning control method of the registration mechanism of a printer that transfers the toner image by conveying and fixes the toner image on the paper, the paper is temporarily stopped by detecting the leading edge of the paper, and the alignment is coincident. A registration mechanism that restarts conveyance at a timing when the sheet is conveyed is rotated at a rising speed lower than a rising conveying speed of the sheet to guide the sheet, and the sheet is released from the sheet after the sheet reaches a certain conveying speed. Features printing positioning control method.