JP2002002038A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer having a simple structure in which print length is not subjected to mechanical restriction of the printer and a clear print can be completed at a specified position of a print medium even when the carrying speed of the print medium is lowered or carriage of the print medium is stopped. SOLUTION: The receiving base of a thermal head 6 and a print medium 1 serves as a platen roll/feed roller 10 which can carry the print medium and a motor 8 for controlling the rotational speed and rotational angle of the feed roller 10 is provided. The print medium 1 is driven by the motor 8 through a bearing 9 in the same direction as a rotational force transmitting means 11. When the carrying speed of the print medium 1 is not lower than a specified level, the feed roller 10 is rotated by the frictional force between the feed roller 10 and the print medium 1 at an outer circumferential speed equivalent to the speed of the print medium 1. When the carrying speed of the print medium 1 drops below the specified level, the feed roller 10 is rotated by means of the motor 8 and the print medium is printed while being carried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing on a film-like printing medium or a sheet-like continuous form to be supplied to a packaging machine or the like, and in particular, it is beautiful even when the transport speed of the printing medium is reduced or stopped. The present invention relates to a printer device capable of printing on a printer.

[0002]

2. Description of the Related Art Conventionally, as such a printer device,
For example, there is one described in JP-A-10-329344. This line thermal head printing device
The thermal head can be moved from the print standby position to the platen side, that is, in the vertical direction, and in the print medium traveling direction, that is, in the front-back direction, and when the print medium stops or falls below a certain speed, the thermal head advances the print medium. The print is performed by moving the print head in the direction opposite to the printing direction so that a clean print is performed.

However, in this method, since the distance over which the thermal head can be moved in the front-rear direction is mechanically limited, this limits the printing length and, when the printing medium stops, the predetermined length on the printing medium is reduced. When the printing position is outside the range of movement of the thermal head, printing is not possible. Further, the mechanism becomes complicated because the thermal head must be moved in the vertical direction and the front-back direction. In addition, if the print medium is suddenly stopped for some reason during printing while the thermal head is stopped at a predetermined speed or more, moving the thermal head back and forth requires an acceleration rise time. There is a problem that the relative speed of the printing medium fluctuates rapidly and the printing becomes unclear.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a printing apparatus which is not subject to the mechanical limitations of the printer apparatus in terms of printing length, has a simple structure, and performs printing even when the transport speed of the printing medium is reduced or the transport is stopped. An object of the present invention is to provide a printer device capable of completing clear printing at a predetermined printing position on a medium.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a feed roller for supporting a print medium and moving in only one direction is provided at a print position or at a position closer to the print medium advancing direction than the print position. And a motor for controlling the rotation speed and rotation angle of the feed roller, and a print medium speed detection means. When the print medium conveyance speed is equal to or higher than a predetermined speed, the feed roller is connected to the print medium. By rotating at a peripheral speed equivalent to the speed of the print medium due to frictional force, and when the transport speed of the print medium is less than a predetermined speed, the feed roller is rotated by a motor so that printing is performed while transporting the print medium. It is what was constituted.

[0006]

The printing apparatus according to the present invention having the above-described structure is free from the mechanical limitations of the printing apparatus in the printing length, and rotates the feed roller even when the transport speed of the printing medium is reduced or stopped. Since the printer itself can convey the printing medium, printing can be reliably completed at a predetermined position on the printing medium.

Further, when the transport speed of the print medium is reduced, the transport speed of the print medium when the motor is started to rotate is made higher than the maximum speed of the outer periphery of the feed roller which can be generated by the rotational speed of the motor. Even if the print medium is suddenly stopped during printing for some reason, the transport speed of the print medium does not suddenly fluctuate below the outer peripheral speed of the feed roller that can be generated by the rotation speed of the motor,
Clear printing can be completed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a thermal transfer printer for printing the date of manufacture, expiration date, manufacturing serial number, etc. on a film supplied to a packaging machine will be described below with reference to the drawings. .

In FIG. 1, reference numeral 1 denotes a printing medium such as a film, which is conveyed in a direction indicated by an arrow by a conveying device such as a packaging machine (not shown). Reference numeral 2 denotes an ink ribbon which is taken up from an ink ribbon supply reel 3 to a ribbon take-up reel 5 via a ribbon guide roller 4. Reference numeral 6 denotes a thermal head, which is pressed from a standby position (not shown) to the feed roller 10 which also serves as a platen roll via the ink ribbon 2 and the print medium 1, and controls the print speed to the speed detected by the print medium speed detecting means 7. The printing speed is followed by the means 14, and heat is generated by an appropriate print pulse by the thermal head print control unit 15 to form a print.

Reference numeral 8 denotes a motor for driving a feed roller 10 via a rotational force transmitting means 11 and a one-way bearing 9. The rotational force of the motor 8 transmits the feed roller 10 only in the conveying direction of the print medium 1, and the motor 8 Is stopped, the feed roller 10 can freely rotate only in the transport direction of the print medium.

After the print command 18 is received from a packaging machine or the like and the print timing marking (not shown) already printed on the print medium is detected by the marking detection means 19, the printing medium speed detection means 7 is provided until printing is completed. If the speed detected by the motor control unit 16 is determined to be equal to or higher than the predetermined speed, the motor control unit 17
Do not rotate.

After the print command 18 is received from the packaging machine or the like, or after the print timing marking (not shown) already printed on the print medium is detected by the marking detecting means 19, the printing is completed until the printing is completed. Medium speed detecting means 7
When the speed detected by is determined by the motor drive management means 16 to be equal to or lower than the predetermined speed, the motor control unit 17 rotates the motor 8 and conveys the print medium 1 by the feed roller 10.

When the print medium 1 is conveyed by the feed roller 10 while the motor 8 is rotated, and the conveying speed of the print medium by a conveying device such as a packaging machine is smaller than the outer peripheral speed of the feed roller which can be generated by the rotation speed of the motor, the printer The printing medium is slackened in the printing medium advancing direction from the apparatus.
This slack is not beneficial for a packaging machine or the like, and can be slackened by providing an appropriate number of dancer rolls 12.

The motor 8 is preferably a servo motor or a stepping motor.

FIG. 2 shows a case where the transport speed of the print medium at the time of starting the rotation of the motor in the embodiment of FIG. 1 is higher than the maximum speed of the outer periphery of the feed roller which can be generated by the rotation speed of the motor. FIG. 4 is a diagram showing an example of a change in the transport speed of a printing medium by the apparatus, a relationship between an outer peripheral speed of a platen roll that can be generated due to the rotation speed of the motor, and an actual printing medium transport speed at that time. V2 is the maximum speed of the outer circumference of the platen roll that can be generated by the rotation speed of the motor,
A curve A is an example showing a state in which the transport speed of the print medium by the transport device such as a packaging machine varies. Curve B shows the platen roll outer peripheral speed that can be generated by the rotation speed of the motor.

The transport speed of the print medium by the transport device is A2
At this point, the printing speed becomes equal to or lower than the printing speed Vl when the motor starts to be rotated, and starts rotating by the motor force, and the possible outer peripheral speed of the feed roller 10 accelerates between Bl and B2 and reaches the maximum speed V2. However, at this time, the print medium transport speed by the transport device is higher, the rotational force of the motor is not transmitted to the feed roller 10 by the one-way clutch action of the one-way bearing, and the actual outer peripheral speed of the feed roller is determined by the transport device. It is equivalent to the print medium transport speed.

Further, the print medium transport speed by the transport device becomes equal to or less than the outer peripheral speed of the feed roller which can be generated by the rotation speed of the motor at point A3, and stops at point A4. Printing is P
Assuming that the printing is started at the point l and completed at the point P2, the actual print medium conveyance speed becomes a curve of Al-A2-A3-B3-B4, and fluctuates below the feed roller outer peripheral speed which can be generated by the rotation speed of the motor. Never.

The embodiment exemplified above shows an embodiment in which the present invention is applied to a thermal transfer printer. In applying the present invention to a thermal transfer printer, the feed roller 10 is connected to the print medium 1. The mechanism is rationalized as a platen roll for receiving the ink ribbon 2, and it goes without saying that the feed roller 10 may be arranged separately from the printing medium 1 and the receiving stand for the ink ribbon 2.

[0019]

As described above, according to the present invention, clear printing can be completed at a predetermined printing position on the printing medium even when the feeding speed of the printing medium is reduced or the feeding is stopped. When the present invention is applied to a thermal transfer printer, the thermal head moves only in one direction, up and down, and is arranged separately from the drive mechanism of the feed roller also serving as the platen roll, so the mechanism is simpler than the conventional method described above. Furthermore, since there is no need to move the thermal head back and forth, it is possible to provide a thermal transfer printer device that always performs beautiful printing without causing any mechanical restriction on the printing length.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of an operation when a conveyance speed of a print medium when a motor starts to be rotated is higher than a maximum speed of an outer periphery of a platen roll which can be generated by a rotation speed of the motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print medium 2 Ink ribbon 3 Ink ribbon supply reel 4 Ribbon guide roller 5 Ink ribbon take-up reel 6 Thermal head 7 Print medium speed detection means 8 Motor 9 One-way bearing 10 Feed roller 11 Rotation force transmission means 12 Dancer roll 13 Control part 14 Print speed management means 15 Thermal head print control unit 16 Motor drive management means 17 Motor control unit 18 Print command 19 Marking detection means

Claims (3)

[Claims] 1. A print command is received from a print medium transport device in the form of a film or a sheet, or a print timing marking already printed on a print medium is detected, and then the print speed is changed according to the transport speed of the print medium. In a printer device that performs printing while rotating, a feed roller that supports a print medium and moves in only one direction is provided at a print position or a print medium traveling direction side from the print position, and a motor that controls a rotation speed and a rotation angle of the feed roller is provided. And a printing medium speed detecting means, wherein when the conveyance speed of the printing medium becomes equal to or lower than a predetermined speed, the motor is rotated to perform printing while conveying the printing medium by a feed roller. . 2. The method according to claim 1, wherein when the transport speed of the print medium by the print medium transport device is reduced, the transport speed of the print medium when the motor starts rotating is higher than the maximum speed of the outer periphery of the feed roller which can be generated by the rotational speed of the motor. The printer device according to claim 1, wherein the printer device is large. 3. The printer according to claim 1, wherein the feed roller also serves as a platen roll.