JPH0815804B2 - Paper transport control method in printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a sheet conveyance control method in a printing apparatus such as a facsimile or a printer.

<Prior Art> There are various methods for cutting a roll-shaped recording sheet, but a cutting method by pressure contact between a fixed blade and a sliding blade is generally used from the viewpoint of cost and reliability.

This sliding blade is pushed down when cutting and returns to the upper side after cutting, but one edge of the cut paper at the time of returning is caught on the upper part of the sliding blade, which hinders the conveyance of paper after cutting. May cause Therefore, after cutting, the paper is retracted by a predetermined amount, and the caught paper is separated from the sliding blade.

The structure will be described with reference to FIGS. 6 and 7. FIG. 6 shows a state when the paper is cut. In the figure, 1 is a roll paper 1A is printed paper, 2 is a thermal print head, 3 is a paper conveying roller connected to a belt gear 3A, and 4 is a fixed blade. ,
5 is a sliding blade, 6 is a paper ejection roller connected to the belt gear 6B, 7 is a leaf spring for pressing the paper against the paper ejection roller, 8
Is a belt, 9 is a belt gear connected to a motor for driving the paper carrying roller, 10 is a paper guide member for guiding the paper fed from the roll paper between the thermal print head and the paper carrying roller, and 11 is a paper ejecting member. It is a belt gear connected to a motor for driving the feeding roller.

At the time of printing, the paper transport roller 3 and the paper discharge roller 6
Prints with the thermal print head 2 while rotating at a constant speed and gripping the paper. For example, when printing of one page is completed, the sliding blade 5 rotates in the direction of the arrow to engage with the fixed blade. Press and cut the paper.

When the cutting is completed, the sliding blade 5 returns in the direction of the arrow in FIG. 7, but if it returns as it is in FIG. 6, the leading edge of the cut paper is caught on the leading edge of the sliding blade 5, so that the paper conveying roller 3 is The sheet is rotated in the direction of the arrow to retract the sheet by a predetermined amount.

If there is no print data to continue at this time, the paper transport roller is rotated in the direction of the arrow as shown in FIG. 7 and the printed paper 1A is discharged to the outside of the apparatus. If there is continuous print data, the paper discharge roller 6 is stopped when the paper transport roller 3 is driven to retract the paper, and starts to rotate at the same speed as the paper transport roller 3 when printing the next data.

<Problems to be Solved by the Invention> In the above-described method, the cutting tip is not caught by the sliding blade and highly reliable paper conveyance is possible. A motor for driving the paper discharge rollers is required for each, and the control for that is complicated.

The present invention has been made in order to solve the above-mentioned conventional problems, and has been made to solve the problem. Even though the number of motors for driving the paper transport roller and the paper discharge roller is one, the front end of the cut paper is slid. By separating and retracting from the moving blade, it is possible to transport the paper with high reliability.

<Means for Solving Problems> A method of controlling paper transportation in a printing apparatus according to the present invention includes a paper transportation roller provided to face a print head, and a paper ejection roller for ejecting printed paper to the outside of the apparatus. Cutting means provided between the paper transport roller and the paper discharge roller for cutting the paper transported by the fixed blade and the movable blade (conventional example, sliding blade in the illustrated embodiment of the present invention). In the printing device, which has the above-mentioned function, the rollers are rotated in the same direction during a printing operation to convey a sheet, and when the printing is completed, the rollers are stopped to cut the printed sheet by the cutting means. A motor serving as a common drive source for the roller and the paper discharge roller, and a power transmission system between the motor and the paper discharge roller are interposed, and the power is transmitted to the paper discharge roller only when the motor rotates in the normal direction. One-way crack The motor is rotated in the reverse direction once the cutting of the printed sheet is completed, and then the motor is rotated in the forward direction to discharge the printed sheet to the outside of the apparatus, and then the motor is rotated in the reverse direction. Control to retract the unprinted paper to the print start position.

<Operation> According to the above control method, by rotating one motor, which is commonly used for the paper transport roller and the paper discharge roller, in the forward and reverse directions, the paper is transported during the printing operation and the movable blade is returned after the paper is cut. Unprinted paper can be prevented from catching, printed paper can be ejected to the outside of the device, and unprinted paper can be set to the print start position, and highly reliable paper transportation can be realized with an extremely simple configuration. .

<Example> Hereinafter, a preferred example of the present invention will be described with reference to the drawings.

FIG. 1 shows the printing operation. The same parts as those in FIG.
The paper discharge roller 6 is connected to the paper transport roller 3 by a belt 8 and the motor 11 is eliminated, and the belt gear 6B is changed to a belt gear 6A composed of a one-way clutch.

When printing is started in this configuration, the belt gear 9 is first rotated by the motor in the arrow direction. This rotation is transmitted to the belt gear 3A by the belt 8 and further transmitted to the belt gear 6A via the belt 8. Therefore, the sheet conveying roller 3 and the sheet discharging roller 6 connected to the respective belt gears start to rotate at the same speed, whereby the recorded sheet 1A is sandwiched by the respective rollers and discharged to the outside of the apparatus. When the printing of data for one page is completed, the paper is cut page by page. The operation is roughly divided into rotation of the sliding blade, restoration of the sliding blade, ejection of printed paper, and unprinted paper. Is set to the print position, and each operation will be described below.

1. Rotation of sliding blade FIG. 2 shows this operation. When printing is completed, the belt gear 9 connected to the motor is stopped. Therefore, the sheet conveying roller 3 and the sheet discharging roller 6 are stopped.
In this state, that is, in the state where the sheet is stopped, the sliding blade 5 rotates in the direction of the arrow, and the sheet is pressed and cut by the engagement with the fixed blade 4.

2. Return of Sliding Blade FIG. 3 shows this operation. When the cutting of the paper is completed by the rotation of the sliding blade 5, the sliding blade 5 returns in the direction of the arrow. Since the tip of the cutting paper may be caught on the tip of the sliding blade 5, the belt gear 9 is driven by a predetermined amount in the direction of the arrow, and the paper transport roller is also rotated in the direction of the arrow to slide the tip of the cutting paper. The moving blade 5 is detached from the tip portion and retracted. At this time, the belt 8 intervening between the belt gear 3A and the belt gear 6A also interlocks, but since the belt gear 6A is configured by a one-way clutch, this rotational force is not given to the paper discharge roller 6. Therefore, when the paper moves backward,
The printed paper 1A is held at the cutting position.

3. Ejection of Printed Paper FIG. 4 shows this operation, and when the sliding blade 5 is completely returned, the printed paper 1A is ejected to the outside of the apparatus. Since this operation is performed by driving the belt gear 9 in the direction of the arrow, it is similar to the printing operation, but the paper transport speed is higher than that during printing.

4. Setting unprinted paper to the printing position Figure 5 shows this operation.
When the sheet is completely discharged to the outside of the apparatus, the unprinted sheet is also conveyed in association with the sheet discharging operation, so that the leading end of the sheet is located near the sheet conveying roller 6. When the next data is printed in this state, the margin of the leading end of the printing paper becomes large. Therefore, the leading end of the unprinted paper is moved back to the next data printing start position by driving the belt gear 9 in the arrow direction. At this time, as described above, the belt gear 8 does not rotate due to the operation of the one-way clutch.

When the series of cutting operations have been completed and there is data to be printed next, the printing operation of FIG. 1 is started again in this state (when the setting operation of the unprinted paper to the printing position is completed).

<Effects of the Invention> As described above, according to the paper conveyance control method in the printing apparatus of the present invention, one motor can be shared as a drive source for the paper conveyance roller and the paper discharge roller, and the motor and both It is not necessary to provide multiple systems as a power transmission system between the rollers, and moreover, forward rotation and reverse rotation of one motor can be repeated to prevent paper from being caught during printing operation and catching unprinted paper when the movable blade returns after cutting paper. It is possible to discharge printed sheets to the outside of the apparatus and set unprinted sheets to the print start position, and it is possible to realize highly reliable sheet conveyance with a simple configuration and control. .

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention, and FIGS. 6 to 7 are views showing a conventional embodiment. 2: Thermal print head, 3: Paper transport roller, 4: Fixed blade,
5: Sliding blade, 6: Paper discharge roller, 6A: Belt gear composed of one-way clutch, 7: Leaf spring, 8: Belt, 9: Drive belt gear.

Claims (1)

[Claims] 1. A paper carrying roller provided to face the print head, a paper discharging roller for discharging printed paper to the outside of the apparatus, and a paper discharging roller provided between the paper carrying roller and the paper discharging roller, It has a cutting means for cutting the paper conveyed by the fixed blade and the movable blade, rotates both rollers in the same direction during the printing operation to convey the paper, and stops both rollers at the end of printing. In a printing device that cuts printed paper by the cutting means, a motor serving as a common drive source for the paper transport roller and the paper discharge roller, and a power transmission system between the motor and the paper discharge roller are interposed. A one-way clutch that transmits power to the paper discharge roller only when the motor rotates in the normal direction, and reverses the motor once after the cutting of the printed paper is completed, and then rotates the motor in the normal direction. By reason And the discharging of the printing paper sheet outside the apparatus, thereafter, the sheet conveyance control method in a printing apparatus characterized by retracting the unprinted paper is reversed the motor to the print start position.