JPS6158773A - Paper feed apparatus - Google Patents

Abstract

PURPOSE:To make it possible to prevent paper from engaging with a feed mechanism part of detaching from a paper support part, by making it possible to selectively perform the correction operation of the mechanistic shift generated at the time of paper feed corresponding to the setting position of the paper. CONSTITUTION:At the time of paper feed in a positive direction, a correction operation unnecessary paper feed signal is outputted to a motor driving circuit 24 to rotate a motor 19. At the time of paper feed in the reverse direction, the feed amount L ahead the press roller part 13 of paper 12 is counted and detected by RAM21 to detect the present position of the paper 12 and a correctable min. feed amount L' is read from ROM22. When L>L', reverse feed is performed to perform correction operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a paper feeding device applied to, for example, a printing device, and in particular to a paper feeding device that corrects uneven printing position due to mechanical deviation of a gear mechanism. Regarding equipment.

[Technical Background of the Invention and Problems Therewith] Generally, a paper feeding device applied to a printing device uses a mechanism that includes a combination of a drive motor, a gear, a toothed belt, a toothed pulley, and the like.

However, in such a mechanism, there is a small gap between the teeth, which causes mechanical misalignment, which reduces the accuracy of feeding the valve assembly, resulting in uneven printing positions.

Conventionally, the following methods have been used to overcome this drawback. In other words, when the paper finally stops before printing, only when the paper is fed in the opposite direction, the specified feed is This is a method of backward feeding by the maximum amount that exceeds the structural deviation between the gear mechanism and the gear mechanism (hereinafter referred to as the correction amount), and then feeding it back in the forward direction by the above correction amount. According to this method, since the contact surface of each tooth of the gear is always on the same side, the stopping position of the paper becomes constant, and therefore the printing position by the print head is made uniform.

However, conventionally, this method has been performed regardless of the initial set position of the paper. Therefore, depending on the position of the paper, there is a problem in that when the correction operation is performed, the end of the paper may get caught in the binding mechanism in the conveyance path or come off the paper support.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to selectively perform correction operations due to structural deviations during paper feeding depending on the set position of the paper. To provide a paper feeding device capable of preventing paper from being caught in a conveyance detection section or coming off from a paper support section.

[Summary of the Invention] The present invention provides a platen that supports paper, a presser roller that presses the paper against the platen, a guide that supports the paper and forms a conveyance path for the paper, and a rotational force applied to the platen. In a paper feeding mechanism having a drive motor that gives a rotational force of Also, by detecting the position of the paper, it is determined whether the paper is at a predetermined position, and the feeding direction of the paper is in the opposite direction;
And when the paper position is at a predetermined position, the drive motor first reverses the paper by an amount that is the sum of the feed amount to the predetermined position and the correction amount due to the rock structure deviation of the gear vibration mechanism. A control means is provided for outputting a control signal that supports sending the correction amount in the forward direction and then returning it by the same correction amount in the forward direction.

Therefore, in the present invention, the correction operation can be performed selectively depending on the position of the paper, and during the correction operation and when feeding the paper after the correction operation, the paper is not in the transport path. This prevents the paper from getting caught in the paper mechanism or coming off the paper support.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 11 denotes a platen, and a paper 12 for printing is pressed against the platen 11 by a warping presser roller 13 and a presser roller 14.

A gear 15 is directly connected to the shaft of the platen 11. The gear 15 is connected via a gear 16 to a gear 17 that is directly connected to the shaft of a drive motor 19, which will be described later. That is, when the drive motor rotates, its rotational force is transmitted to the platen 11 by the gear 17.16.degree. 15, and the binding paper 12 is sent along the guide 18.

FIG. 2 shows the configuration of the control section 20 in the paper feeding mechanism. This control unit 20 controls the feed f of the paper 12 from the presser portion to the leading end C by the warpage presser roller 13.
A RAM (Random Access System) that counts and detects f1L and stores the position of the paper 12.
r'yf) 21, the minimum feed ffiL (min) that can be corrected for the above-mentioned feed ff1L, that is, the leading edge C of the paper 12 will not come off the warpage presser roller 13 even if extra reverse feeding is performed to perform the above-mentioned correction operation. ROM (Lead Ω-n I
Viemor'T/ ) 22, these RA
CPU 23 receives and receives data from M21 and ROM 22 and outputs control signals;
The motor drive circuit 24 receives a control signal from the drive motor 19 and outputs a drive signal to the drive motor 19.

Next, the operation of the paper feeding mechanism will be explained with reference to the flowchart shown in FIG. First, CPU 23 is ROM2
Recognize the need for paper feeding according to the program in 2 (
In step S1>, a paper feed signal that does not require a correction operation in the case of forward paper feed is output to the motor drive circuit 24. As a result, the motor drive circuit 24 outputs a forward rotation signal to the drive motor 19. Therefore, the motor 19
The gear 17 rotates in the direction shown by arrow A in the figure, and the rotational force is transmitted to the gear 17.
．． 16.15 to the platen 11, as a result of which the platen 11 rotates in the direction of arrow B. Since the paper 12 is supported by the presser roller 14, it is fed along the conveyance path 18 in the direction of arrow C (forward direction). At this time, if the paper 12 is located between the platen 11 and the warping press roller 13 in the initial state, the edge of the paper 13 will not come off the warping press roller 13 (step S2
).

Next, in the case of paper feeding in the reverse direction, the RAM 21 counts and detects the feed ff1L of the paper 12 from the presser roller 13 section, and the current position of the paper 12 is detected (
Step 33). The detection signal of this RAM21 is
23. On the other hand, a signal indicating the correctable minimum feed IL (min) is read into the CPU 23 from the ROM 22 (step 84). However, C.P.
In U23, input RAM21 and ROM
Data L and L (min) from 22 are compared and calculated,
Either paper feeding with a correction operation or paper feeding without a correction operation is selected (step S5), and the motor drive circuit 2
A control signal is sent to 4. That is, l<l(m
In), if the paper 12 is fed backwards for the correction operation, the leading edge C of the paper 12 will come off the presser roller 13, so the paper 12 is not fed backwards. Also, conversely, L>L (m
In the case of (i), the leading edge C of the paper 12 does not come off the presser roller 13 even if the correction operation is performed, so in this case, reverse feeding is performed and the correction operation is performed. (Step Ss). Therefore, the paper 12 is sent in the opposite direction by an amount equal to the amount of feed to the predetermined position plus the amount of correction due to the structural deviation in the column for each gear, and then returned in the forward direction by the same amount of correction m. The printing position is corrected.

In the above embodiments, an example was explained in which the present invention was applied to a paper feeding device of a printing device, but the present invention is not limited to this, and of course can be applied to a paper feeding device of a copying device, etc. .

[Effects of the Invention] As described above, according to the present invention, the paper feed correction operation can be performed by
This can be done selectively depending on the paper position.
During the correction operation and during the paper feed after the correction operation, the paper does not get caught in the mechanical part in the conveyance path or comes off from the paper support part, and stable paper feed can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a paper feeding device according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control circuit of the device, and FIG. 3 is a flowchart showing the operation of the device. DESCRIPTION OF SYMBOLS 11...Platen, 12...Paper, 13. Curved press roller, 15, 16.17...Gear, 18...Transport path, 19...Motor, 2°...Control unit, 21・RA
M, 22-ROM, 23-CPU. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] A platen that supports paper, a presser roller that presses the paper against the platen, a guide that supports the paper and forms a conveyance path for the paper, a drive motor that applies rotational force to the platen, and this drive motor. A gear mechanism that transmits the rotational force of the paper to the platen, and a gear mechanism that determines whether the feeding direction of the paper is forward or reverse, and detects the position of the paper so that the paper is at a predetermined position. If the feeding direction of the paper is in the opposite direction and the paper position is at a predetermined position, the drive motor is first given the feed amount to the predetermined position and the paper feed amount to the predetermined position. The paper is characterized by comprising a control means for outputting a control signal to send the paper in the reverse direction by an amount equal to the amount of correction due to mechanical deviation of the gear mechanism, and then to send the paper back in the forward direction by the same amount of correction. paper feeding device.