JP2882447B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for performing transfer printing on paper using an ink ribbon.

[0002]

2. Description of the Related Art Conventionally, a printer for performing transfer printing includes a thermal head 1 and a roller-shaped platen 2 as shown in FIG. 5, for example, and an ink ribbon is provided between the thermal head 1 and the platen 2. 3, the paper P is guided by a paper feed roller 4 arranged upstream of the head position.

The platen 2 is driven to rotate by the same motor as the paper feed roller 4, and is moved toward and away from the thermal head 1 so as to be relatively pressed against and separated from the thermal head 1.

The ink ribbon 3 has a supply section and a winding section,
In the supply unit, the ink ribbon 3 is pulled out in accordance with the print conveyance, and in the winding unit, the ink ribbon 3 continuously carried out from the head position by the driving of the winding motor is wound up.

When the paper is fed, the platen 2 is separated from the thermal head 1, and the paper P is guided between the platen 2 and the ink ribbon 3 by the paper feed roller 4.
When the print position of the paper P reaches the head position, the platen 2 moves in the direction of the thermal head 1 and presses the paper P and the ink ribbon 3 against the thermal head 1,
In a state where the ink ribbon 3 and the ink ribbon 3 are brought into close contact with each other, the thermal head 1 transfers and transfers the print. At the same time, the winding unit is driven by a winding motor to wind up the ink ribbon 3 carried out from the head position. Further, when the printing position of the paper P has passed from the head position, the platen 2 is moved away from the head, the winding motor is stopped, and only the paper P is conveyed.
The paper P that has passed the head position is carried out by the downstream transport system.

[0006]

SUMMARY OF THE INVENTION In a conventional printer,
When the rear end of the paper P passes through the head position and is carried out by the downstream transport system, as shown by a two-dot chain line in FIG.
The ink ribbon 3 that has been in close contact with the platen 2 is pulled out together, causing a slack, and sometimes the slack portion of the ink ribbon 3 sticks to the peripheral surface of the platen 2. The platen 2 moves away with the passage of the paper P, but the platen 2 driven by the same motor to keep the paper feed roller 4 rotating for feeding the subsequent paper P is in a rotating state. When the slack portion of the ink ribbon 3 adheres to the peripheral surface of the platen 2, the ink ribbon 3 may wind around the peripheral surface of the platen 2. The occurrence of the slack of the ink ribbon 3 tends to become more remarkable as the paper P is transported at a higher speed.

When the winding of the ink ribbon 3 occurs, the ink ribbon 3 wraps around the peripheral surface of the platen 2 in a short period of time, and the platen 2 locks.
The state reaches an abnormal state such as a jam of the succeeding sheet P. When such an abnormal state is reached, it takes much time and trouble to eliminate the winding of the ink ribbon 3 and the jam of the paper P.

When the paper P passes from the head position, the platen 2 is moved away from the head, and the driving of the winding unit is stopped. However, by slightly driving the winding unit, the ink ribbon 3 is moved. Although it is possible to take up the slack by winding a certain amount, even if the slack is slightly generated, the ink ribbon 3 is further wound up by a certain amount, so that the consumption of the ink ribbon increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a printer capable of detecting winding of an ink ribbon around a platen beforehand and controlling the winding of the ink ribbon. I do.

[0010]

According to the present invention, there is provided a print head, a platen for positioning and transporting an ink ribbon and a paper to a print position facing the print head, a platen motor for rotating the platen, A take-up motor that rotationally drives a take-up unit that takes up the ink ribbon carried out from the position of the head; and detects an ink ribbon that moves along the peripheral surface of the platen on the downstream side in the conveyance direction from the position of the print head. And a control means for stopping the platen motor when the ink ribbon is detected by the detection means, and winding the ink ribbon by driving the winding motor.

[0011]

According to the present invention, when the ink ribbon is pulled out together with the paper passing through the print head position, slack occurs in the ink ribbon, and the slacked ink ribbon adheres to the peripheral surface of the platen, and the peripheral surface of the platen is rotated. Even if it moves along with the surface, the ink ribbon moving along the peripheral surface of the platen is detected by the sensor, and the platen motor is stopped, and the ink ribbon is wound by driving the winding motor. In addition, the slack of the ink ribbon is automatically eliminated, and the winding of the ink ribbon around the platen is prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the printer according to the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic structure of a printing portion of a printer. Numeral 11 denotes a printer employing, for example, a thermal head as a print head. A printing surface 12 in which heating elements (not shown) are arranged along a width direction orthogonal to the transport direction A is formed downstream of A, and a guide member 13 is attached upstream of the printing surface 12.

A platen 21 is arranged to face the printing surface 12 of the thermal head 11. The platen 21 has a roller portion 22 and a shaft portion 23. The roller portion 22 has at least a white surface and elasticity, and the shaft portion 23 is rotatably supported by a platen support mechanism (not shown). And platen 21
Is a platen motor 24 consisting of a stepping motor.
2 (shown in FIG. 2), and is selectively moved toward and away from the thermal head 11 by a platen support mechanism. The platen motor 24
Is used for driving a paper feed roller (not shown) that feeds the paper to the head position on the upstream side in the transport direction from the head position.

Reference numeral 31 denotes a ribbon cassette. In the ribbon cassette 31, a supply hub 33 and a take-up hub 34 are rotatably supported by a case 32, and an unused ink ribbon 35 is wound around the supply hub 33. The ink ribbon 35 having passed the head position is wound on the winding hub 34 by being turned. A plurality of guide members 36a, 36 are provided from the supply hub 33 to the head position.
The head is guided by the separation member 37 and a plurality of guide members 38a and 38b. Further, a back tension member 39 that applies back tension to the ink ribbon 35 by urging of a spring (not shown) is rotatably mounted in the middle of the path from the supply hub 33 to the head position.

The ribbon cassette 31 is detachably attached to and replaceable with a printer base (not shown). When the ribbon cassette 31 is mounted, the supply hub 33 is engaged with the delivery shaft 40 and the winding hub 34 is mounted.
Engages with a winding shaft 41 as a winding unit. The delivery shaft 40 gives resistance to the rotation of the supply hub 33 and gives tension to the ink ribbon 35 pulled out to the winding side. The take-up shaft 41 is driven to rotate in the direction of the arrow by a take-up motor 42 (shown in FIG. 2) composed of a DC motor.

At the downstream side in the transport direction from the head position, a sensor 51 is provided as detection means for detecting the ink ribbon 35 which has slackened along the roller portion 22 in opposition to the peripheral surface of the roller portion 22 of the platen 21. Have been. This sensor 51 is shown in FIG.
As shown in the figure, the light emitting diode 52 and the light receiving transistor 53
And a reflection type photo sensor in which the surface of the roller portion 22 normally receives the reflected light reflected in white, the transistor 53 is turned on, and the slacked ink ribbon 35 is generated.
Is moved along the surface of the roller portion 22 to the sensor position, the amount of light reflected from the non-white ink ribbon 35 such as black decreases, and the transistor 53 is turned off. The on / off signal of the transistor 53 is output to an I / O port 65 described later.

FIG. 2 is a block diagram of the printer. Reference numeral 61 denotes a CPU as control means. A system bus 62 of the CPU 61 has a ROM 63 storing a control program and the like, and a RAM 64 capable of writing and reading various data as needed. Is connected.

An I / O port 65 is connected to the system bus 62 of the CPU 61. The thermal head 11, the motor 24 for the platen, the winding motor 42 and the sensor 51 are connected to the I / O port 65. In addition, the I / O port 65
A keyboard 66 for inputting instructions such as printing start and printing stop, and a display unit 67 for displaying operation status and the like are connected.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

First, when the power of the printer is turned on (step 1), the transport system of the printer is driven for a predetermined time to carry out the paper remaining in the printer (step 2), and the winding motor 42 is turned on. Drive for a predetermined time and drive the ink ribbon.
The roll is wound up to an extent that absorbs 35 slacks (step 3), and is set in a standby state (step 4).

When the print key of the keyboard 66 is turned on (step 5), the transport system in the printer including the motor 24 for the platen is driven (step 6), and the paper is transported to the head position. The sheet conveyed to the head position is guided between the ink ribbon 35 and the platen 21 moving away from the thermal head 11.

When the printing position of the paper reaches the head position, a printing operation is started (step 7). In this printing operation, the platen 21 moves in the direction of the thermal head 11,
The paper and the ink ribbon 35 are pressed against the thermal head 11, and the paper and the ink ribbon 35 are conveyed while performing thermal transfer printing with the thermal head 11 in a state of being in close contact with the ink ribbon 35. At the same time, the take-up motor 42 is driven to take up the ink ribbon 35 carried out from the head position. When the print position of the paper passes from the head position, the platen 21
The take-up motor 42 is stopped while moving away from 11, and only the sheet is conveyed. When there are a plurality of printing positions on one sheet, the printing operation is repeated for each printing position.

Then, the printed paper passes the head position. At this time, the ink ribbon 35 that has been in close contact with the sheet is pulled out together, causing a slack, and the slack portion may stick to the peripheral surface of the roller unit 22 of the platen 21. The platen 21 moves away as the paper passes, but the platen 21 driven by the same drive source, that is, the platen motor 24, keeps the paper feed roller rotating for feeding the subsequent paper. Therefore, when the slack portion of the ink ribbon 35 adheres to the peripheral surface of the roller portion 22, the ink ribbon 35 may wind around the peripheral surface of the roller portion 22.

As described above, the ink ribbon having the slack is generated.
When the roller 35 has moved along the roller portion 22, it is detected by a sensor 51 arranged on the peripheral surface of the roller portion 22 so as to face the shaft portion 23 downstream of the head position in the transport direction (step 8).

When the sensor 51 detects the slack of the ink ribbon 35, the transport system including the motor 24 for the platen and the winding motor 42 are stopped (step 9). Thereafter, the process returns to step 2 to drive the transport system of the printer to carry out the paper remaining in the printer, and to drive the winding motor 42 to wind up the slack of the ink ribbon 35 to enter a standby state.

If no slack in the ink ribbon 35 is detected in step 8, the printed paper is carried out (step 10), and if printing is to be continued on the next paper, the flow returns to step 6 for printing. Perform the operation (Step 1
1).

As described above, the ink ribbon 35 is
It is possible to prevent an abnormal state in which the ink ribbon 35 is tightly wound around the ink cartridge 21 beforehand, and it is possible to automatically eliminate a large slack of the ink ribbon 35. In addition, since the winding is performed only when the ink ribbon 35 becomes slack, the ink ribbon 35 is not wasted.

[0029]

According to the present invention, even if the slacked ink ribbon sticks to the peripheral surface of the platen and moves, the ink ribbon is detected by the detecting means, the motor for the platen is stopped, and the winding is performed. By driving the take-up motor to take up the ink ribbon, the slack of the ink ribbon is automatically eliminated, and the ink ribbon can be prevented from winding around the platen.

[Brief description of the drawings]

FIG. 1 is a front view illustrating an embodiment of a printer according to the present invention.

FIG. 2 is a control block diagram of the embodiment.

FIG. 3 is a circuit diagram of the sensor of the embodiment.

FIG. 4 is a flowchart illustrating an operation of the printer according to the embodiment.

FIG. 5 is an explanatory diagram illustrating slack of an ink ribbon in a conventional printer.

[Explanation of symbols]

 11 Thermal head as print head 21 Platen 24 Platen motor 35 Ink ribbon 41 Take-up shaft 42 as take-up unit 42 Take-up motor 51 Sensor as detection means 61 CPU as control means

Claims (1)

(57) [Claims] 1. A print head, a platen for positioning and transporting an ink ribbon and paper to a print position facing the print head, a platen motor for driving the platen to rotate, and an ink carried out from the position of the print head A take-up motor that rotationally drives a take-up unit that takes up a ribbon; a detection unit that detects an ink ribbon that moves along the peripheral surface of the platen at a position downstream of the print head in the conveyance direction; And a control means for stopping the platen motor when the ink ribbon is detected in step (a), and winding the ink ribbon by driving the winding motor.