JPH0431071A - Printing device - Google Patents

Abstract

PURPOSE:To remove a sag in a sheet due to the rotating-amount of a feed roller during reverse rotation by allowing a rotation equal to a single signal automatically in a forward feed direction immediately after backward rotation of the feed roller in a fixing part when the sheet is fed backward for adjustment of a sheet printing start position. CONSTITUTION:When a sheet 1 is moved in a forward direction (arrow 12), a motor 26 and a stepping motor 25 are allowed to rotate in a forward direction through a control part 27 by pressing a forward feed button 32. Subsequently, the transport mechanism of a tractor wheel part and a feed roller 24 are allowed to rotate in a forward direction. In this case, the rotating amount of the motor 26 is controlled by the number of button pressings. When the sheet is moved in a backward direction (arrow 13), a reverse rotation signal equal to pressing value is connected to the motor 26 by the control part 27, if a backward feed button 33 is pressed. A motor forward rotation signal (c) is automatically connected to the stepping motor 25, unless a motor feed rotation signal equal to a pressing value is issued to the stepping motor 25 and a next backward feed button is pressed. This forward rotation signal is equal to a signal generated by the single pressing of the forward direction feed button.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device, and more particularly to a printing device having a function of aligning the paper start position and performing forward and reverse feeding.

[Conventional technology]

Conventional printing devices that use continuous paper use an electrophotographic method to fix toner as a visible image on the paper using a heated roll. Furthermore, since the printing start position of the paper is determined, a paper feeding function is provided to perform positioning.

Next, an example of a conventional printing device will be described with reference to the drawings. In FIG. 2, a continuous sheet of paper 1 is fed from a paper feed section 2, and a tractor section 3 transfers toner 11, which has been reimaged at an electrophotographic section 4, and attaches it to the paper. It is fixed by passing between the pressed rollers 21 and 22), and is discharged and folded into the stacker section 6 via foot rolls 23 and 24.

The two heat rollers are in pressure contact only during printing; otherwise they are separated as shown in the figure to prevent the sheets from coming into contact with each other.

There are indication marks 3 on the tractor section for aligning the starting position of the paper.
1, and before printing, adjust the printing start position using the paper forward feed button 32 and the reverse feed button 33. The paper is fed in the forward direction or in the reverse direction using only the conveyance mechanism section of the tractor section and the feed roll.

[Problem to be solved by the invention]

In the above-mentioned conventional printing apparatus, the amount of paper feeding is accurately determined by the paper conveying section of the tractor section, and the feed roller rotates more than the amount of paper movement to give tension to the paper. Therefore, when reverse feeding is performed, the amount of rotation of the feed roller is greater than the amount of movement of the paper, causing the paper to become slack. If the sheet is repeatedly fed backwards, the amount of slack increases, causing friction with the heat roller (lower side) which is constantly rotating in the forward direction, and the roller, which is normally charged, becomes even more frictionally charged and causes the paper to wrap around it.

[Means to solve the problem]

In order to solve the above-mentioned problems, the printing device of the present invention includes a first paper feeding means and a second paper feeding means provided at two places on the conveyance path for conveying one sheet of paper, and a a process of driving the first and second paper feeding means in the first direction when feeding paper by a set length without printing from the paper feeding means to the first direction of the second paper feeding means; and a process of driving the first paper feeding means in a direction opposite to the first direction.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

To move the paper 1 in the forward direction (arrow 12) during paper feeding to align the paper with the print start position, press the forward feed button 32 to control the motor 2 via the control unit 27.
6 and a command to rotate the stepping motor 25 in the forward direction. Upon receiving the command, the motor rotates the conveyance mechanism of the tractor unit 3 in the forward direction, and the stepping motor rotates the feed roller 2.
Rotate 4 in the forward direction. At this time, the amount of rotation of the motor is controlled by the number of button presses.

When moving the paper in the opposite direction (arrow 13),
When the reverse feed button 33 is pressed, the control unit displays a as shown in FIG.
A signal is received from the control section, and a reverse rotation signal corresponding to the depression is output to the motor 26. The stepping motor 25 that rotates the feed roller is given a motor feed rotation signal corresponding to the amount of press.
If the next reverse feed button is not pressed, a motor forward rotation signal C is automatically sent to the stepping motor 25. This forward rotation signal is a signal equivalent to one press of the forward direction feed button.

〔Effect of the invention〕

As explained above, the present invention includes a control that automatically rotates the feed roller of the fixing unit by one signal in the forward feed direction immediately after the feed roller of the fixing unit is rotated in the reverse direction during reverse feed for paper print start position alignment. This has the effect of eliminating slack in the paper due to the rotation amount of the feed roller during feeding.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a paper feeding mechanism according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing a printing apparatus to which the embodiment of the present invention is applied, and Fig. 3 is a signal diagram showing its control method. FIG. l... Continuous paper, 2... Paper feed section, 3...
...Tractor, 4...Electronic photography department, 5...
... Fixing section, 6 ... Stacker section, 11 ...
・Toner, 12...Paper feed forward direction arrow, 13...
・Paper feed reverse direction arrow, 21 ・Heat roller (top),
22...Heat roller (lower), 23...Feed roller 24...Feed roll, 25...Stepping motor, 26...Motor, 27...
Control unit, 31... Instruction mark, 32... Forward feed button, 33... - Reverse feed button. Agent Patent Attorney Susumu Uchihara 23 Sue): '0-tl/ No.!

Claims (1)

[Claims] A first paper feeding means and a second paper feeding means provided at two places on a conveyance path to convey one sheet of paper, and a first direction from the first paper feeding means to the second paper feeding means. a process of driving the first and second paper feeding means in the first direction when feeding the paper by a set length without printing; and a process of driving the first paper feeding means in the opposite direction to the first direction. A printing device characterized in that it has a process of driving the paper to