JP2000335033A - Thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer printer in which tension of an ink ribbon can be set normally even immediately after replacement of the ink ribbon. SOLUTION: The thermal transfer printer comprises a ribbon replacement sensor 13 for detecting the mounted/demounted state of a thermal transfer ribbon, and means 11 for turning a ribbon feed motor at a rotational speed corresponding to the ribbon diameter detected when replacement of the thermal transfer ribbon is detected by the ribbon replacement sensor 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer, and more particularly to a thermal transfer printer which detects that a thermal transfer ribbon has been replaced.
The present invention relates to a thermal transfer printer that detects a ribbon diameter and rotates a ribbon feed motor at a rotation speed corresponding to the detected ribbon diameter.

[0002]

2. Description of the Related Art A color thermal transfer printer that performs printing using a plurality of ink ribbons has a plurality of print blocks including a thermal head and a platen arranged in series along a paper transport path.

Each ink ribbon is housed in an ink ribbon magazine. The ink ribbon magazine includes a feed roller that winds an unused ink ribbon in a roll shape and a take-up roller that winds the ink ribbon printed by the ink ribbon.

The rotation of the feed roller and the take-up roller is controlled by a DC motor. Then, by detecting the rotation of the slit plate synchronized with the rotation axis of the feed roller with a sensor, the ribbon diameter is calculated, and the voltage of the DC motor is controlled in accordance with the calculated ribbon diameter, thereby controlling the ink ribbon. Optimum tension applied to

More specifically, the control is performed such that the rotation speed of the DC motor decreases as the ribbon diameter increases, and the rotation speed of the DC motor increases as the ribbon diameter decreases.

By controlling in this way, the tension applied to the ink ribbon is optimized.

Such detection of the diameter of the ink ribbon has been performed when printing is performed.

[0008]

By the way, in a color thermal transfer printer in which printing is performed using a plurality of ink ribbons by a plurality of thermal heads, if the ink ribbon of the color to be printed is not set as an ink ribbon magazine. Is to remove the unused ink ribbon magazine set in the printer and replace the ink ribbon magazine of the color to be printed.

However, even if the ink ribbon magazine is replaced, the ribbon does not rotate unless printing is performed, so that the ribbon diameter cannot be detected. That is, immediately after the replacement of the ink ribbon magazine, the rotation speed of the DC motor is controlled in accordance with the ribbon diameter of the previously mounted ink ribbon magazine.

Therefore, if the ribbon diameter of the ink ribbon magazine before replacement is small and the ribbon diameter of the ink ribbon magazine after replacement is large, the ink ribbon of the ink ribbon magazine after replacement is replaced with the ink ribbon before replacement. Since the ink ribbon is fed at a high rotation speed corresponding to the ribbon diameter, wrinkles are generated on the ink ribbon, and there is a problem that the print quality is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to detect the ribbon diameter and set the ink ribbon tension to a normal one even immediately after the replacement of the ink ribbon. It is an object of the present invention to provide a thermal transfer printer capable of performing the above.

[0012]

According to a first aspect of the present invention, there is provided a thermal transfer printer for performing printing by transferring ink on the thermal transfer ribbon to a print medium by using heat generated in a thermal head using the thermal transfer ribbon. Detachable state detecting means for detecting the state of detachment of the thermal transfer ribbon to the printer, and detecting the ribbon diameter when the thermal transfer ribbon has been replaced by the detachable state detecting means, and detecting the detected ribbon diameter And rotation control means for rotating the ribbon feed motor at a rotation speed corresponding to the rotation speed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic system configuration of the thermal transfer printer.

In FIG. 1, reference numeral 11 denotes a controller for controlling the thermal transfer printer. This controller 1
1, a timer for counting the time and a flag F which is set when the ribbon is replaced are provided in addition to the program for performing the control shown in the flowcharts of FIGS.

The controller 11 has a sheet sensor 12 for detecting the leading end of the sheet P conveyed as shown in FIG. 5A, and a ribbon sensor for detecting a ribbon exchange which will be described later with reference to FIGS. 7 and 8. Is connected to a ribbon exchange sensor 13 as a detachment state detecting means.

Further, the controller 11 is connected to a motor control unit 14, a head control unit 15, and a ribbon control unit 16.

The motor control unit 14 controls the rotation of a motor M1 for controlling the conveyance of the sheet P.

The head controller 15 controls energization of the thermal head 17 based on print data sent from the controller 11.

The ribbon control section 16 controls a motor M2 for controlling the rotation of a feed roller for feeding the ink ribbon and a winding roller. Here, although the motors for controlling the rotation of the feed roller and the winding mora are provided separately,
Here, only the motor M2 for controlling the rotation of the winding roller is shown.

Next, the configuration around the thermal head will be briefly described with reference to FIG. In FIG. 5A,
A platen roller 21 is provided so as to face the thermal head 17. The rotation of the platen roller 21 is controlled by the motor M shown in FIG.

A transport path formed upstream of the thermal head 17 has a paper sensor 12 for detecting the leading edge of the paper P.
Is provided.

In addition, the above-described motor M
1 is provided with a transport roller 22 whose rotation is controlled.

Next, a schematic configuration of a color thermal printer to which the present thermal transfer printer is applied will be described with reference to FIG.

On the paper transport path 32, ink ribbon magazines 33 to 36 are sequentially and detachably provided in series.
In these ink ribbon magazines 33 to 36, ink ribbons of yellow, magenta, cyan, and black are set, respectively.

Each of the ink ribbon magazines 33 to 36 is provided with four
Head blocks 37 to 40 are provided. Each of the head blocks 37 to 40 is provided with platens 41 (21) to 44 facing each other with the transport path 2 interposed therebetween.

For example, the paper supplied from the paper supply port 45-1 via the transport roller 46 (22) and the auxiliary roller 47 disposed opposite to the transport roller 46 is transported through the transport path 32, and Ink ribbon magazine 33
To 36 (each head block). Then, the paper passes through the ink ribbon magazines 33 to 36, and printing is performed.
1 is discharged outside.

The transport path 32 from the paper supply port 45-1 to the first ink ribbon magazine 33 for printing is provided with a transport roller 46 and an auxiliary roller 47 arranged opposite to the transport roller 46. I have.

The auxiliary roller 47 is rotatably supported by an auxiliary roller mounting member 47-2 rotatably provided on the color printer main body 31 by a rotary shaft 47-1. Further, a guide roller 47-3 for urging the sheet toward the conveyance path 2 is provided on the auxiliary roller attaching member 47-2.
Is provided. The auxiliary roller mounting member 47
The state where −2 is turned upward is shown by a broken line in FIG.

The surface of the transport roller 46 is made of a material having a high coefficient of friction, such as rubber, and has a higher friction coefficient than the surface of each of the platens 41 to 44. The conveying force (holding force) of the continuous paper by the auxiliary roller 47 is equal to each of the platens 41 to 44.
Is greater than the continuous paper transport force (tensile force). The transport roller 46 is formed by a roller called a projection roller or a thermal spray roller.

A gear is connected to the rotation shaft of the first transport roller 46, and this gear is connected via a plurality of gears to a gear connected to the rotation shaft of a first motor 48 composed of a stepping motor. The rotation of the transport roller 46 is controlled by the first motor 48.

The rotation axis of the platen 41 disposed opposite the first printing head block 37 in the magazines 33 to 36, and the second printing head block 3.
Gears having different gear ratios are respectively connected to the rotation shafts of the platen 42 disposed opposite to each other, and each gear is connected to the rotation shaft of a second motor 49 composed of a stepping motor via a plurality of gears. The rotation of the platens 41 and 42 is controlled by the second motor 49.

The rotation axis of the platen 43 disposed opposite the head block 39 for printing third,
Gears having different gear ratios are respectively connected to the rotation shafts of the platen 44 disposed opposite to the head block 40 for printing, and each gear is a third motor composed of a stepping motor via a plurality of gears. The third motor 50 controls the rotation of the platens 43 and 44. The third motor 50 controls the rotation of the platens 43 and 44.

The second motor 49 and the third motor 49
Motor 50 and a plurality of gears connected between the two motors 39 and 50 and the platens 41 to 44 adjust the rotation speed of each motor 49 and 50 and the gear ratio of each gear. Thus, the peripheral speed of each of the platens 41 to 44 is designed to be higher than the peripheral speed of the transport roller 46, and to gradually increase in the order of printing.

Each of the head blocks 37 to 40 has a printing position which moves vertically above the platens 41 to 44 and has a down position in contact with an up position separated from the platens 41 to 44. Thermal heads 51 to 54 are provided as heads. In FIG. 6, each of the thermal heads 51 to 54 is located at a down position where printing can be performed on paper.

Further, each of the thermal heads 51
The entirety of the head blocks 37 to 40 having the heads 54 to 54 are rotatably provided in the main body of the color printer 31 by a fulcrum shaft 55 in a vertical direction.

FIGS. 7A and 7B schematically show the ink ribbon magazines 33 to 36, the closed head blocks 37 to 40 in the cantilever state, and the open head blocks 37 to 40 in the open state. FIG. 3 is a diagram illustrating a configuration.

An ink ribbon is mounted on the ink ribbon magazine 33.
Is detachably attached to the printer body 31.
A microswitch 61 is provided at a portion where the printer main body 31 and the ink ribbon magazine 33 are joined, as a detachable state detecting means. In other words, when replacing the ribbon,
Since the ink ribbon magazine 33 is detached from the printer main body 31 and another ribbon magazine is set in the printer main body 31, it is possible to detect that the ribbon has been replaced by monitoring the on / off state of the micro switch 61. Can be.

FIGS. 8 and 9 are diagrams for explaining another example of the detached state detecting means for detecting ribbon exchange.

In FIG. 8, side plates 71 and 72 are provided in a part of the printer main body 31. This side plate 71
And 72 are provided with a head release shaft 73. At one end of the head release shaft 73,
A head-up lever 74 is attached. The rotation of the head-up lever 74 causes the head-up lever 7 to rotate.
The head mounting bracket 75 attached to the rotary head 4 rotates to move the thermal head 51 to the up position or the down position.

The other end of the head release shaft 73 has a D-cut shape as shown in FIG. A micro switch 76 for detecting rotation of the head release shaft 73 is provided in the lower half of the D-cut shape.

That is, when ribbon exchange is performed,
The head release shaft 73 is rotated, the head release shaft 73 is rotated, the thermal head 51 is set to the up position, the ink ribbon magazine 33 is removed from the printer main body 31, and another ribbon magazine is set in the printer main body 31. Therefore, by monitoring the on / off state of the microswitch 76, it is possible to detect that the ribbon has been replaced.

Each of the ribbon feeding mechanism and the winding mechanism is 1
Are provided one by one. The ribbon winding mechanism will be described with reference to FIG. In the figure, reference numeral 81 (M2) denotes a ribbon winding DC motor. A ribbon winding shaft 82 is provided in parallel with the rotation shaft 81a of the DC motor (M2) 81. Between the rotation shaft 81a of the DC motor (M2) 81 and the ribbon winding shaft 82, a transmission mechanism 84 constituted by a gear train formed by meshing a plurality of gears 83 is provided. A winding roll (not shown) is attached to the ribbon winding shaft 82.

On the outer peripheral portion of the ribbon winding shaft 82, a slit disk 85 having a number of slits 85a formed on the outer peripheral portion at predetermined intervals is provided so as to rotate in synchronization with the ribbon winding shaft 82. It is. Further, an optical sensor 86 for detecting the presence or absence of the slit 85a is provided with a slit disk 85.
Is provided on the outer peripheral side. Then, by detecting the time until the next slit 85a is detected from the slit 85a by the sensor 86, the change time of the slit 85a is detected. Here, since the running speed of the ribbon is constant, the ribbon diameter can be calculated from the time. That is, as the ribbon diameter increases, the radius at which the ribbon is wound from the center of the ribbon winding shaft 82 increases, so that the change time of the slit 85a changes according to the ribbon diameter. Then, by driving the DC motor M2 (81) with a voltage corresponding to the calculated ribbon diameter, the ribbon tension can be kept good.

Next, the operation of the embodiment of the present invention configured as described above will be described. First, signal processing output from the ribbon exchange sensor 13 will be described with reference to the flowchart of FIG. Ribbon exchange sensor 13
Are input to the controller 11. And
The controller 11 determines whether the ribbon exchange sensor 13 has been turned on (step S1). Ribbon exchange sensor 1
When it is determined that No. 3 has been turned on, the ribbon exchange flag F is set (step S2).

By the way, the label issuing process is performed in the flow chart of FIG.
This is performed by the processing of the chart. First, controller 1
1 outputs a control signal to the motor control unit 14, the rotation of the platen motor M is started, and the conveyance of the paper P is started at time t0 as shown in FIG. 5A (step S1).
1).

Next, it is determined whether or not the leading edge of the sheet P is detected by the sheet sensor 12 (step S12). When the position shown in FIG. 5B and the leading end of the sheet P reach the position of the sheet sensor 12 while the sheet P is being conveyed, "YES" is determined in the step S12, and the process proceeds to the step S13. In this step S13, the timer T is driven (time t1).

Next, it is determined whether the ribbon replacement flag F has been set (step S14). If the determination in step S14 is "NO" (that is, the ribbon replacement flag F
= 0), the time t3 at which the timer T measures the predetermined time T1 at which the sheet P comes to the position shown in FIG.
Waiting is performed (step S15). here,
The position shown in FIG. 5D shows the position where printing is started when the paper P reaches the thermal head 17.

At time t3, a control signal is output to the head control unit 15 and the ribbon control unit 16, so that the ink ribbon is fed and wound, and printing is performed in the thermal head 17 (step S16).

Then, it is determined whether the printing is completed (step S17). Then, when it is determined that the printing has been completed, a series of processing ends.

The above-described printing process is for the case where the ribbon has not been replaced.

In step S14, "YE
If "S" is determined, that is, it is determined that the ribbon has been replaced, the ribbon replacement flag F is first reset (step S18).

The time t at which the leading edge of the sheet P is detected
After a lapse of a predetermined time T0 from 1, the sheet PT is changed to the state shown in FIG.
A process of waiting for the vehicle to reach the position is performed (step S1).
9). Here, T0 <T1 is set. here,
FIG. 5C shows the position of the sheet sensor 1 as shown in FIG.
5 shows an intermediate position from the detection of the leading end of the sheet P to the position shown in FIG.

At time t2, the ribbon control unit 16
A control signal is output to drive the ribbon,
The ribbon diameter is measured (Step S20).

Then, the motor M2 is rotated at a rotation speed corresponding to the ribbon diameter measured in step S20 (step S21).

Then, a process of waiting for the sheet P to reach the position shown in FIG. 5D is performed (step S22). That is, a process of waiting for the timer T to measure the predetermined time T1 is performed.

That is, when the ribbon is exchanged,
As shown in FIG. 2, the ribbon diameter is detected after a predetermined time T0 from the time t1 when the leading edge of the sheet is detected, and the rotation of the ribbon winding and ribbon feed motor is controlled at a rotational speed according to the ribbon diameter. (Rotation control means). Therefore,
The tension of the ink ribbon can be set to a normal value even immediately after the replacement of the ink ribbon.

On the other hand, when the ribbon is not replaced, as shown in FIG. 2, the time t1 when the leading edge of the sheet is detected.
After a predetermined time T1 (> T0), the ribbon control is performed.

Thereafter, the above-described processing after step S16 is performed, and printing is performed.

Although the ribbon control section 16 is provided separately from the controller 11 in the above-described embodiment, the ribbon control section 16 may be provided in the controller 11.

[0060]

According to the first aspect of the invention, immediately after the replacement of the ink ribbon, the diameter of the ribbon is calculated, and the rotation of the motor for transferring the ribbon at a rotational speed corresponding to the ribbon diameter is controlled. Accordingly, even immediately after the replacement of the ink ribbon, the tension of the ink ribbon can be set to a normal value.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a thermal transfer printer according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the embodiment.

FIG. 3 is a flowchart for explaining an issuing process according to the embodiment;

FIG. 4 is a flowchart for explaining a ribbon replacement monitoring process of the embodiment.

FIG. 5 is an exemplary view for explaining the position of a sheet in the issuing process according to the embodiment;

FIG. 6 is a diagram illustrating a schematic configuration of a color thermal printer.

FIG. 7 is a diagram showing a schematic configuration of a head block.

FIG. 8 is a diagram showing a schematic configuration of a head block.

FIG. 9 is a perspective view showing a D-cut shape provided on the other end side of the head release shaft.

FIG. 10 is a diagram showing a ribbon feeding mechanism and a ribbon winding mechanism.

[Explanation of symbols]

 11: controller, 12: paper sensor, 13: ribbon replacement sensor, 14: motor controller, 15: head controller, 16: ribbon controller, 17: thermal head.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hisashi Tsujimura 570 Ohito, Oni-cho, Taga-gun, Shizuoka Pref.

Claims (1)

[Claims] 1. A thermal transfer printer for performing printing by transferring ink on a thermal transfer ribbon to a print medium by heat generated in a thermal head using the thermal transfer ribbon, wherein a detachment for detecting a detachment state of the thermal transfer ribbon to the printer. A state detecting means for detecting a ribbon diameter when the thermal transfer ribbon has been replaced by the detachable state detecting means, and rotating the ribbon feed motor at a rotational speed corresponding to the detected ribbon diameter; A thermal transfer printer comprising control means.