JPS60193669A - Drive controller of paper feeding roller in printer - Google Patents

Abstract

PURPOSE:To eliminate the needs to control the time of the reduction of rotational inertia and reversal action of a DC motor by a method in which an one- way clutch capable of rotation and transmission only in the normal turning direction is interposed in a reduction gear train and the DC motor is controllably turned reversely when stopping the paper feeding action. CONSTITUTION:For a line printer for example, when the head has N group of dots M, printing for every one group (dots M) is made at the start of printing, during which period the next data are started to receive. At the time when the printing of X group is ended, reversal control is applied to DC motor 2 to allow the motor 2 being turned normally to turn to some extent by its rotational inertia, but the DC motor 2 is quickly decelerated and stopped and then turned reversely alightly. Since the reversal turning is not transmitted to the platen 11 side by an one-way clutch 10, a paper is stopped at a given printing position to prevent the occurrence of overrun. The time of reversal action to be applied when stopping the paper feeding action by normal turning can be set up at a fixed value all the time or roughly regardless of normal turning speeds for each time, and the feeding of paper to given angle positions can be exactly performed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a drive control device for a paper feed roller in a printer, and particularly to a drive control device for a paper feed roller in a printer in which the paper feed roller is driven by a DC motor. It is related to the device.

[Prior art]

Generally, a stepping motor is used to drive a paper feed roller in a printer. This stepping-
In the case of a motor, the stepping motor is rotated by a predetermined angle each time the current printing line is finished, and the next printing line is fed to the set printing position.
Since the motor itself has a rotation angle detection means, it is possible to accurately feed the paper to the set printing position. However, since this stepping motor is expensive, it has been considered to replace it with an inexpensive DC motor. So, send that paper υ
It is necessary to apply braking and reversal action (in this case, a controlled time reversal so that the paper feed roller itself is not reversed) for each rotation, to reduce its rotational inertia, and to accurately stop the paper at a predetermined angular position. . However, when the rotational speed of the DC motor is constant, the braking and reversal action times can also be kept constant, but when this rotational speed changes, the rotational speed is detected each time the paper feed is performed, and the rotation This has the disadvantage that the braking and reversal action times must be controlled in accordance with the speed, making the device configuration and control extremely complex.

[Summary of the invention]

In view of these conventional drawbacks, the present invention provides a printer in which the rotation of a DC motor is transmitted to a paper feed roller through a reduction gear train. By interposing a clutch, this one-way clutch disables rotation transmission in the reverse direction, and by controlling the DC motor in reverse when the paper feed operation is stopped, rotational inertia can be reduced. This eliminates the need for time control of action.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a drive control device for a paper feed roller according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show the front and main parts of the apparatus configuration of this embodiment. In each of these figures, a DC motor 2 is mounted and fixed inside the housing side plate 1.
is capable of rotational drive in the forward direction shown by the solid line arrow and in the reverse direction shown by the dotted line arrow, and a reduction gear train 5 is connected to the motor gear 4 at the shaft end of the output shaft 3 protruding to the outside of the same side plate 1. It is connected. And this reduction gear train 5 is
A first reduction gear 6 of the first stage meshed with the motor gear 4 and an intermediate gear T coaxial therewith; a second reduction gear 8 of the second stage meshed with this intermediate gear T and a second reduction gear coaxial therewith; A one-sided clutch 10 is interposed between the first reduction gear 6 and the intermediate gear 7, and transmits rotation only in the normal rotation direction indicated by the solid line arrow.
Each of these gears is appropriately pivoted on the outer surface of the side plate 1,
Only the rotation of the DC motor 2 in the forward direction is decelerated and transmitted. Further, the platen 11 as a paper feed roller is also rotatably supported by the side plate 1, and the platen gear 12 at the shaft end taken out from the outer surface is connected to the intermediate gear 9 which is the final stage gear of the reduction gear train 5. They are meshed with each other, and printing paper (not shown) is fed by the forward rotation of the DC motor 2. The DC motor 2 is driven and controlled by a command from a control circuit 13 that controls the printer, and an impeller 14 for detecting the print position is provided in the drive system after the one-way clutch 10.

Next, the time chart of FIG. 3 shows the relationship between the two printing paper feeds and the controls for the motor in the embodiment apparatus having the above configuration. The thermal head method is used for printing here, and the printer is a line printer with a head fixed to the width of the printing paper, and the head is equipped with N groups of M dots. do.

In FIG. 3, the control circuit 13 first receives data of one dot line (MXN dots) (step 21.
22), the DC motor 2 is rotated forward (step 23), and the paper is fed to a predetermined printing position (step 24).
) and printing is started (step 25).

And to start this printing, for each group (M dot)
is printed, and during that time the next data reception starts (step 26), but when the printing of group X is finished (step 27), reverse control is applied to the DC motor 2 and it stops (step 28). be done.

At this point, the DC motor 2, which had been rotated in the normal direction due to this reversal control, is rotated to a certain extent due to its rotational inertia, but it is rapidly attenuated and stopped. It will be reversed slightly. However, this reverse rotation is not transmitted to the side platen 11 by the one-sided clutch 10 interposed in the reduction gear train 5, so that the printing paper is stopped and maintained at a predetermined printing position, and its overrun is prevented. It is.

After that, the printing of (X+1), (X+2), etc. groups continues, and the printing of the last N group is completed (
Step 2B) Then, it is determined whether the data of the next one-dot line has been received or not (Step 30). From (steps 31 and 32), the DC motor 2 is rotated forward, and similar operations are performed thereafter.

In the above time chart, the timing for reverse control of the DC motor is set at the time when the print of group X by the head is completed, but it is not necessarily limited to this point in time, and may be set at the printing position, for example. The control signal may be taken from a range that is after the printing position and can be stopped before the printing of N groups is completed, taking into account the rotational inertia of the DC motor.

In addition, in the description of the embodiment device, a printing method using a thermal head was described, but it goes without saying that any other printing method may be used. It can also be applied to the reader (transmitter) side.

〔Effect of the invention〕

As detailed above, according to the present invention, in the case of a configuration in which the rotation of the DC motor is transmitted to the paper feed roller via the reduction gear train, a one-sided clutch capable of transmitting rotation only in the normal rotation direction is provided to the reduction gear train. Since we have made it impossible to transmit rotation in the reverse direction by intervening the motor, and the DC motor is controlled in the reverse direction when the paper feed operation stops, the reverse rotation operation time given when the paper feed operation stops due to normal rotation is Regardless of the normal rotation speed, it is possible to always set a constant value, and even roughly set it to that value, so that paper feeding to a predetermined angular position can be carried out accurately, and therefore, paper feeding There is no need to detect the rotational speed for each rotation and change the reversal operation time each time.As a result, the device configuration can be simplified and control operations can be made easier. It's something you get.

[Brief explanation of the drawing]

1 and 2 are a front view and a partially cutaway plan view showing an embodiment of a drive control device for a paper feeding roller 2 according to the present invention, and FIG. 3 is a flowchart showing an example of a drive control program for the same as described above. It is. 2-...DC motor, 4...Motor gear, 5...
... Reduction gear train, B, 7... 1st reduction gear, intermediate gear, 8 + 9-@・Φ 2nd reduction gear. Intermediate gear, 10.Φ.-one side clutch, 11e@tatami/platen (paper feed roller), 12..-platen gear, 13.. control circuit. Patent Applicant: Tamura Electric Manufacturing Co., Ltd. Agent: Kazuko Yamakawa (I and 2 people) Route 1, Gyowan, 2, and 3

Claims (1)

[Claims] In a printer that uses a DC motor as a drive source and transmits the rotation of the DC motor to a paper feed roller through a reduction gear train, the DC motor can be controlled to rotate in both forward and reverse directions, and A one-sided clutch capable of transmitting rotation only in the forward direction is interposed in the reduction gear train, and when the paper is fed to a predetermined position by rotation of the DC motor in the forward direction, the DC motor is controlled in the reverse direction. 1. A drive control device for a paper feed roller in a printer, characterized in that: