JP2000016691A - Paper folding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hardly cause paper jam and realize a stable folding work by detecting a reference position of a roll action of a swing fin which applies a folding force to a continuous paper having pleats and by changing an inversion timing of the roll action based on the feeding speed of the continuous paper. SOLUTION: As for a delay time (loss time) of an actual swing fin to the ideal speed of the swing fin in changing the paper feed speeds W, W', the loss time generally shows no change with the change in paper feed speed. However, the loss time increase, as the paper feed speed W enhances. The standard position (home position) of the swing fin facing its right below is detected and values T1, T2 of the inversion timing T are changed according to the paper feed speed so as to be set to their optimal values. The swing fin folding back timing is changed according to the paper feed speed so that the stable folding performance with less paper jam can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper folding apparatus provided with a swing fin for applying a folding force to continuous paper having a fold.

[0002]

2. Description of the Related Art A laser beam printer is illustrated in FIG. 2 as a typical apparatus to which a paper folding apparatus is applied.
When a signal for starting a printing operation is issued from a controller for controlling the laser beam printer,
The photoconductor 1 starts rotating. The photoconductor 1 rotates at a speed corresponding to the printing speed of the laser beam printer, and continues to rotate until the printing operation ends. When the photoreceptor 1 starts rotating, for example, a positive high voltage is applied to the charger 2 to uniformly charge the surface of the photoreceptor 1 with a positive charge. The polygon mirror 3 is a polyhedral reflecting mirror. The polygon mirror 3 starts rotating as soon as the power is turned on. The polygon mirror 3 rotates at a constant speed with high accuracy as long as the power is turned on. The light is reflected by the polygon mirror 3 and is emitted while scanning the photoconductor 1 through the Fθ lens 5.

[0003] Character and graphic data converted to a dot image are issued from a controller to a laser beam printer as a laser beam on / off signal, and a portion of the photoreceptor 1 irradiated with laser light and a portion not irradiated are formed.
The irradiation of the laser beam causes the charge on the photoconductor 1 to disappear, and when that portion reaches the front of the developing device 6, the positively charged toner is attracted by static electricity and a toner image is formed on the photoconductor 1. When the head of the print data formed on the photoreceptor 1 by the laser beam comes before the transfer device 7,
The tractor 8 is driven such that the head of the paper 13 on which the data is printed (paper folding perforation) comes before the transfer device 7.

[0004] The paper 13 is moved by the tractor 8 from the hopper to the developing unit including the photoreceptor 1, the developing unit 6 and the transfer unit 7.
The sheet is transported to the fixing unit. The sheet 13 that has reached the fixing unit 9 is preheated by a preheating plate 10, and then heated by a heat roller 11 and a pressure roller 1.
2, the toner image is melted and fixed on the sheet 13 by being conveyed while being pressed and heated. Printed paper 1
The stacker table 3 is folded by the swinging operation of the swing fin 14 according to the folding perforation, and the folding state is adjusted by the rotating paddle 15.
6 on top of each other.

FIG. 3 shows a conventional swing fin unit. The rotation of the stepping motor 30 is reduced by the gear head 31. The rotation of the motor is transmitted by a timing belt 32 to a pulley 33 fixed to a swing fin shaft 34. The swing fin 14 is fixed to the swing fin shaft 34.
That is, in the swing fin unit, in order to swing the swing fin 14, the stepping motor 30 may be rotated by switching the rotation direction in the CW / CCW direction. Therefore, the swing angle of the swing fin 14 can be freely selected by controlling the number of operation steps of the stepping motor 30.

[0006] An encoder plate 37 is fixed to the swing fin shaft 34, and the position of the swing fin 14 is detected based on the positional relationship with the photo interrupter 36. In this conventional example, a position where the swing fin 14 faces directly below will be described as a basic position (hereinafter, referred to as a “home position”).

The control of the swing fin unit according to the conventional example will be described with reference to FIGS. When the signal P FEED-P rises as a signal inside the printer in synchronism with the DVS-P signal generated at a cycle corresponding to the time for feeding 1/6 inch paper, and the microcomputer section 38 rises. A signal SWING DRV-P for operating the stepping motor 30 is issued to the stepping motor control unit 39. This signal rises in synchronization with the first input DVS-P signal after the rise of PFED-P.

In this configuration, a timing chart when the swing fin 35 starts moving from the home position in the CCW direction is shown. CW to move the stepping motor 30 in the CCW direction from the microcomputer 38
-P signal is issued at "L" level. Further, the microcomputer increments a counter for counting the number of steps each time the stepping motor 30 is operated by one step.

As shown in FIG. 5, if the turning point on the CCW side is assumed to be n, the number of CCs until the counter value becomes n is reached.
The swing fin 35 operates toward the W side, and the SWING
DRV-P becomes “L”, and the swing fin 35 stops. Next, when TURN-P is input, the operation direction of the swing fin 35 is changed to CW-P in order to operate in the CW direction.
Becomes “H”. After the TURN-P signal is input, the swing fin drive is restarted at the first DVS-P input. The TURN-P signal is issued at a sheet feeding time interval corresponding to the sheet length of the sheet to be printed, and the issuing timing is to count the DVS-P signal so that the swing fin 35 should reach the turning point. Is managed by In FIG. 5, m is the count value.

While the swing fin 35 moves in the CW direction, the encoder plate 37 and the photointerrupter 3 are moved.
6 from the home position sensor consisting of
-P changes from "L" to "H", which forcibly corrects the counter to 2n. In the same manner, the swing fins 14 are controlled in the same manner, and the swing fins are turned back at the point of the counter 3n. When the HOME-P changes from "H" to "L", the counter is forcibly rewritten to 0.

If the swing fin 14 is operating at the time when the TURN-P signal is received, an immediate stop operation is started and the system waits for the next DVS-P. P FEED-P falls,
When the paper feeding operation is completed, the SWING DRV-P is depressed by the next DVS-P signal input, and the swing fin 14 is stopped.

As described above, by clearing the counter upon detection of the home position, the swing fin 1
By correcting the position information of No. 4 and determining the turn-back timing by the TURN-P signal, it is possible to correct the temporal phase shift of the swing fin 14 with respect to the paper feed. Further, by providing the value of the turning point n for each sheet length, a swing angle according to the sheet length can be selected. The rotation speed of the stepping motor 30 is substantially constant because the swing angle is small for short paper and large for large paper. FIG. 9 shows an outline of the operation of the swing fin 14 controlled as described above.

[0013]

In the above-mentioned conventional control,
The turning-back timing of the swing fins 14 was the same regardless of the paper feed speed. That is, the value of m at which the TURN-P signal is generated in FIG. 5 is determined so that the position of the folding perforation is generated at the same time as passing through the same position with respect to the tip of the swing fin 14.

FIG. 6 shows the relationship between the speed of the swing fin 14 and the paper feed time t. The timing 55 indicated by A in FIG. 6 is the timing at which the perforation passes through the tip of the swing fin. In the figure, a solid line 51 is an ideal speed of the swing fin 14, and a broken line 52 is a speed of the swing fin when the motor for driving the swing fin is controlled by rotating the motor forward / reverse and no motor start-up time is required. The dotted line 53 indicates the speed of the swing fin when the motor is required to start up and the control is performed by rotating the motor forward / reversely. The solid line 54 indicates that the motor driving the swing fin is rotated in one direction by the link mechanism. This is the speed of the swing fin. Swing fin 14 is solid line 5
As shown in FIG.
Is ideally changed from −V to −V, but in an actual method including the method shown in the conventional example, a delay always occurs.

For example, even in the case of a link system in which the motor is controlled to rotate in one direction and the motor does not need to be reversed, the point at which the tip of the swing fin 14 switches the moving direction is determined by the swing fin rotation circumferential tangent. Since the speed in the direction becomes slow, a delay corresponding to the area 58 shown by C in the figure and a loss time 58 occur. In addition, when a forward / reverse rotation is performed by using a stepping motor as described in the conventional example, a start-up time is required, or a swing after the TURN-P signal is output as described in FIG. A fixed control time (including processing time of a microcomputer or the like) until the fin motor 30 starts rotating
Is required.

When the paper feed speed is constant, it is necessary to take this delay into account, that is, to set the value of m in FIG. 5 to a value taking into account the loss time 58. By adjusting the timing at which the sheet 14 is inverted, the sheet can be folded so as not to cause a jam or the like.

However, when the paper feeding speed changes, such as in a printer having a plurality of paper feeding speeds or in a post-processing device connected to a printer having various paper feeding speeds, the value of m is constant, ie, the swing fin In the conventional control in which the reversal timing and the positional relationship between the tip of the swing fin 14 and the perforation at that timing are constant, it has been difficult to achieve stable paper folding at all paper feeding speeds.

An object of the present invention is to provide a sheet folding apparatus which is less likely to cause a sheet jam at various sheet feeding speeds and can realize a stable folding operation.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to provide a swing fin which is swingably supported and applies a folding force to a creased continuous paper, and a reference position for the swing operation of the swing fin. And a control means for changing the reversal timing in the swinging operation of the swing fin based on the feed speed of the continuous paper.

[0020]

Embodiments of the present invention will be described below. Since the basic configuration is the same as that of the conventional example, description thereof will be omitted, and control of the swing fin will be described below.

In this embodiment, a case where the mechanism shown in FIG. 3 can be operated at a usable speed without slowing up the stepping motor will be described as an example. FIGS. 7 and 8 show the paper feed speed (shown as W and W ′ in the drawings).
Delay time (loss time) of the actual swing fin with respect to the ideal speed of the swing fin when the angle changes
Is shown.

FIG. 7 shows the case where the paper feed speed is slow, and FIG. 8 shows the case where the paper feed speed is faster than FIG. In FIG. 7 and FIG. 8, a region B58 is a loss time generated when the swing fin is reversed and started up. In the present embodiment, since the stepping motor is not slowed down, it is a control delay time of a stepping motor controller such as a microcomputer. is there.

Generally, the loss time does not change even if the paper feed speed changes. However, as is clear from FIGS. 7 and 8, the loss time 57 shown in the area B58
Increases as the paper feed speed W increases. In the present invention, the value of m in FIG. 5, that is, the value of T in FIG.

[0024]

As described above, according to the present invention, since the swing fin folding timing is changed according to the paper feeding speed, a stable folding performance with less paper jam can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a swing fin turnback timing according to the present invention.

FIG. 2 is a schematic view of a laser beam printer.

FIG. 3 is a perspective view of a swing fin unit.

FIG. 4 is a block diagram of a swing fin drive unit.

FIG. 5 is an explanatory diagram of a swing fin operation timing.

FIG. 6 is an explanatory diagram showing a relationship between a swing fin turnback timing and a swing fin speed.

FIG. 7 is an explanatory diagram showing the relationship between the swing fin turning timing and the swing fin speed when the paper feed speed is low.

FIG. 8 is an explanatory diagram showing the relationship between the swing fin turning timing and the swing fin speed when the paper feed speed is high.

FIG. 9 is a diagram illustrating the operation of a swing fin.

[Explanation of symbols]

14 is a swing fin, 15 is a paddle, and 16 is a stacker table.

Claims (1)

[Claims] 1. A swing fin which is swingably supported and applies a folding force to a continuous sheet provided with a fold,
Reference position detecting means for detecting a reference position of the swinging fin's swinging operation, and control means for changing a reversal timing in the swinging fin's swinging operation based on a feed speed of the continuous paper. Paper folding device.