JPH02209274A - Thermal transfer recorder - Google Patents

Abstract

PURPOSE:To prevent the step-out of a stepping motor to ensure the discharge of recording paper by starting the acceleration of the stepping motor after a predetermined time has elapsed after the start of a DC motor. CONSTITUTION:After a printing is finished, recording paper is discharged in the state that a thermal head is most separated by a depressing/releasing mechanism. In this paper discharge action, a DC motor and a stepping motor are rotated at high speed. The high-speed rotation drive of the stepping motor results in a small torque, and a difference in an accelerating ratio causes a step-out. Then, the discharge of the recording paper is ensured in such a manner as a voltage is applied to the DC motor for driving a platen roller 2 to make the DC motor rotate and, thereafter, the acceleration of the stepping motor for driving a capstan roller 3 is started after a sufficient delay time for preventing the step-out of the stepping motor for driving the capstan roller 3 has elapsed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a thermal transfer recording device, and particularly to a multicolor thermal transfer recording device capable of producing multicolor recording.

(b) Conventional technology As disclosed in Japanese Patent Application Laid-open No. 149463/1983, in a multicolor thermal transfer recording device that uses cut-shaped recording paper, the conveyance of the recording paper is carried out by a platen roller. I am doing it. That is, the recording paper is wrapped around the platen roller over a circumference of about 180 degrees or more, the recording paper is held on the platen roller by a rubber roller that presses against the platen roller, and the recording paper is conveyed as the platen roller rotates.

Further, as disclosed in Japanese Utility Model Application Laid-open No. 62-85443, there is one that uses a roll of recording paper, in which the recording paper is conveyed by a conveyance roller separate from the platen roller.

In the former method, in which the recording paper is conveyed by a platen roller, the platen roller is made of a rubber elastic material such as CR, so the printing pitch in the sub-scanning direction is not constant due to deformation of the platen roller, and the A3 size print ±1aun in photo
In addition, weak paper such as melt-type recording paper tends to wrap around the platen roller, but strong paper such as sublimation-type recording paper and OHP film tend to wrap around the platen roller. It is difficult to adhere to the outer periphery of the roller, often causing it to float. If floating occurs on the platen roller, the recording paper cannot be conveyed accurately.

On the other hand, in the latter method, which uses rolled recording paper and conveys the recording paper by a conveyance roller separate from the platen roller, the recording paper does not slacken between the platen roller and the conveyance roller, so a constant tension is maintained. There is a need. For this reason, conventionally, a friction clutch mechanism was installed at the mounting part of the roll recording paper to increase the tension by one foot.
As the roll diameter changes, the tension changes, causing the paper to sag between the platen roller and the transport roller, or being pulled too much, causing the recording paper to shift on the transport roller, making it impossible to accurately transport the recording paper.

Further, in the case of cut-shaped recording paper, it is not possible to apply tension at the mounting portion, so that accurate conveyance of the recording paper is impossible.

(C) Problems to be Solved by the Invention By the way, the capstan roller of the conveyance roller is driven by a stinger motor, the platen roller is driven by a DC motor, and the main conveyance of the recording paper is performed by the conveyance roller, so that cutting is possible. It is possible to apply tension to the shaped recording paper between the conveyance roller and the platen roller.

However, with the configuration described above, a problem occurs when accelerating the recording paper with the recording paper sandwiched between both rollers, such as when ejecting the recording paper. In other words, there is a difference between the acceleration rate of a stepping motor and the acceleration rate of a DC motor, and since the acceleration rate of a stepping motor is high, it is a DC motor! If you try to accelerate the stepping motor immediately after applying pressure, the DC motor cannot accelerate in time, so the platen driven by the DC motor passes the recording paper and brakes against the capstan roller driven by the stepping motor. This causes the stepping motor to step out of step.

To prevent this tax adjustment, it is necessary to make the acceleration rate of the DC motor and the acceleration rate of the stepping motor the same. Acceleration of the stepping motor is performed by referring to an acceleration table, but if you try to match the acceleration rate of the stepping motor to that of the DC motor, it is necessary to provide another acceleration table in addition to the one normally used. There is a problem in that the control becomes complicated.

The present invention provides a thermal transfer recording device that solves this problem.

(d) Means for Solving the Problems The present invention involves inserting a recording paper and an ink sheet in a superimposed manner between a platen roller and a thermal head disposed opposite to the platen roller, and inserting the ink sheet onto the recording paper. A thermal transfer recording device that transfers ink of The stepping motor is driven by a predetermined period of time after the DC motor starts to be activated.

(e) Action: In the predetermined time until the stepping motor starts accelerating,
The DC motor can be sufficiently accelerated, and the platen roller does not act as a brake on the rotation of the capstan roller through the recording paper. However, stepping motors will not be taxed.

(Hen. Example An embodiment of the present invention will be described below with reference to the drawings.

Thermal head (1) facing the platen roller (2)
is fixed to the head support plate (5).

The head support plate (5) is rotatably supported on the head rotation shaft (6) fixed to the left and right frames, and can swing toward and away from the platen roller (2). It becomes. Further, the head support plate (5) is connected to the link C (10) via a joint D (14).

This link C (10) is connected to link A (8) and link B (9) by joint B (12).

Further, link A (8) is connected to joint A (11) inside spur gear A (20). The spur gear A (20) is rotatably supported by the six spur gear rotation shafts (26), and the spur gear B (21) is in contact with the spur gear A (20). Two left and right spur gears B (2
1) is fixed to a through shaft (22) and rotated by a motor (not shown). This rotation control is performed by a sensor plate (24) attached to the shirt (22).
) of the sensor (23).
) The link B (9) is then connected to the spring plate (15) by the link C (13). A heel pressure contact spring (17) is hung on the spring plate (15) at a notch portion, and the other end of the head pressure contact spring (17) is fixed to a spring support (19) provided on the frame. Head pressure spring (17
) is applied to the spring plate (15) by the frame (25-a) (
The spring plate rotation shaft (16) provided in the frame (25-a) (25-b) is rotated counterclockwise in the middle. It is regulated by a spring plate stopper (18).

1. The operation of this embodiment will be explained below.

FIG. 1 shows a side view of the pressure contact/release lateral groove showing a state in which the thermal head is the most spaced apart. Through shaft (22)
When the motor, not shown, connected to
, by the flat wheel A (20), the joint A (1
1) around the spur gear A rotating shaft (26) in the direction of the arrow in the figure (
It is transmitted to rotate it (counterclockwise). As a result, the head support plate (5) rotates clockwise around the head rotation axis (6), so that the thermal head (1) moves in a direction in which it comes into pressure contact with the platen roller (2). As this operation continues, the thermal head (1) and platen roller (2) reach a state where the heads begin to come into pressure contact, as shown in FIG. In Figure 2, the motor (not shown) connected to the through shaft (22) is rotated in the direction of the arrow (clockwise).
When further rotationally driven, this force acts in the direction of increasing the angle θ formed by link B (9) and link C (10). Here, since the platen roller (2) is pivotally supported between the frames, the thermal head (1) cannot move downward any further. Therefore, the force that tries to widen the above-mentioned angle θ is transmitted through the joint C (13) in a direction that rotates the spring plate (15) clockwise around the spring plate driving wheel (16). FIG. 4 shows the state in which the head is in the most pressure contact. Continuing from the state shown in Figure 2, when the motor (not shown) connected to the through shaft (22) is further rotated in the direction of the arrow in the figure (clockwise), the opening angle of the toggle joint gradually approaches 180°. , the head pressure spring (17) is stretched. The couple force applied to the spring plate (15) of the head pressure contact spring (17) becomes a force that tries to push down the head support plate (5-) via the joint D (14), that is, the platen of the thermal head (1) This becomes a pressing force against the roller (2).

The thermal head pressure contact force in this example is 5±0, 5k
g, so in Figure 1, the distance between the head rotation axis (6) and joint D (14) is 55 mm, and the head rotation axis (
6) and the distance between the pressure contact between the platen roller (2) and the thermal head (1) is =901+1Zl, so F*
=4.09kg. (As shown in Figure 5, FT has two locations on the left and right, so the required force is 5 x "0/, I = 8.18 kg.
Half of that is fine. ) The distance between the centers of the joint C (13) and the spring plate rotating shaft (16) is 1OfflI11. Pressure contact spring (
The distance to the point where 17) is applied (the point of action of the head pressure spring) is 20 ma+, so the spring force is 4.09 x lo
8.=2.045kg is required. This spring force was generated when the thermal head (1) was brought into maximum pressure contact (FIG. 4), that is, when the head pressure contact spring (17) was extended the most.

From the state shown in Fig. 4, when the motor (not shown) connected to the through shaft (22) is further rotated in the direction of the arrow in the figure (clockwise), the thermal head (1) is released from the platen roller (2). Return to the state shown in Figure 1.

Now, 1. Recording paper (3) fed by a paper feeding mechanism (not shown)
6) is detected by vapor sensor A (32) and guides the recording paper (36) to the main body. At this time, the platen roller (
2) is rotated by a DC motor (not shown) in the direction of the arrow in the figure, and inserts the recording paper (36) between the platen roller (2) and the platen pinch roller (31) as shown in FIG. At this time, the distance between the platen roller (2) and the thermal head (1) is approximately 2ffl! 11 apart.

Simultaneously with the start of rotation of the platen roller, the capstan roller (3) is driven to rotate in the direction of the arrow in the figure by a stepping motor (not shown).
) is inserted into the gap between the cab dunn roller (3) and the capstan press roller (4) using the ink sheet (30) and the thermal head (1) as guides. Paper loading is performed in this manner.

When paper loading is completed, the thermal head (1) comes into pressure contact with the platen roller (2) as shown in FIG. 4, and printing is performed. At this time, the recording paper (36) is sandwiched between the cab dunn roller (3) and the capstan pressing roller (4), and is conveyed by the rotation of the capstan roller (3).

The platen roller (2) cuts the electromagnetic club that is connected to it, making it rotatable. Here, the recording paper (36) generates appropriate tension between the platen roller (2) and capstan roller (3) due to the pressure contact force of the thermal head (1), so the recording paper (36) does not sag during this time. .

Note that during recording, the stepping motor is rotated at a constant speed, and the torque is large (there is no risk of step-out due to tension).

In this embodiment, printing is performed as described above, but printing may be performed without disengaging the electromagnetic clutch. That is, the tension generated between the platen roller (2) and the cab dump roller (3) increases by the amount of torque required to rotate the DC motor connected to the platen roller (2) in this embodiment. When the platen roller (2) is provided with a friction clutch lateral groove, the torque increases by the amount of torque of the friction clutch mechanism.

When printing is completed, the state returns to the state shown in FIG. 3, and the recording paper (36) is reversely conveyed by the capstan roller (3). At this time, the platen roller (2) and thermal head (1) are approximately 20! It is set to be separated by LL1.

Here, the platen roller (1) rotates an electromagnetic clutch (not shown) ONL, drives a DC motor (not shown) at a constant voltage, and rotates in a direction to reversely convey the recording paper.

At this time, the platen roller (2) and capstan roller (3)
) If the tension of the recording paper between the capstan rollers (3) and the capstan pressure roller (4) is too large, it will not be possible to hold the recording paper (36) between the capstan roller (3) and the capstan presser roller (4), and the recording paper will be held on the capstan roller (3). (36) slips. therefore,
Accurate conveyance of the recording paper by the capstan roller (3) becomes impossible.

In addition, if the tension of the recording paper is too low, the tension of the recording paper (3) between the platen roller (2) and the cab dunn roller (3)
6) Deflection: Even if the recording paper is accurately conveyed by the capstan roller (3), the recording paper may be misaligned on the platen roller (2) where printing is actually performed.

Therefore, it is necessary to maintain the tension of this recording paper at an appropriate level. In this embodiment, when the recording paper is fed backwards, the platen roller (2) is driven by a DC motor (not shown), the capstan roller (3) is driven by a pulse motor (not shown), and when there is no recording paper (36), Platen roller (2)
The circumferential speed of the capstan roller (3) was set to be greater than the circumferential speed of the capstan roller (3).

When the printing is completed, the thermal head is in the state shown in FIG. 1, which is the most spaced apart state due to the pressure contact/release lateral groove. In this state, print 4 Jli sheets of recording paper.

In this paper ejecting operation, the DC motor and stepping motor are driven to rotate at high speed. When a stepping motor is driven to rotate at a high speed, its torque decreases and, as mentioned above, it loses synchronization due to the difference in acceleration rate.

Therefore, in the present invention, in order to reliably eject the recording paper at this part, firstly, the DC
After applying voltage to the motor, rotating the DC motor, and allowing a sufficient delay time to prevent the stepping motor that drives the cab dump roller (3) from stepping out,
This starts the acceleration of the stepping motor that drives the capstan roller (3).

With this configuration, the DC motor can be sufficiently accelerated in a predetermined time period until the stepping motor starts accelerating, and the platen roller does not act as a brake on the rotation of the capstan roller through the recording paper. Therefore, no load is applied to the stepping motor and no step-out occurs.

(I.) As described in detail, according to the present invention, after starting the DC motor, without performing complicated control such as providing a special acceleration table for the stepping motor, , by starting to accelerate the stepper motor,
PJt adjustment of the stepping motor is prevented, and recording paper can be ejected reliably.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 to 4 are side views showing different states of contact and separation between the thermal head and the platen roller. 1... Thermal head, 2... Platen roller, 3
... Capstan roller, 4 ... Capstan pressing roller, 30 ... Ink sheet, 31 ... Platen pinch roller, 36 ... Recording paper.

Claims (1)

[Claims] (1) A thermal transfer recording device in which a recording paper and an ink sheet are inserted in a superimposed manner between a platen roller and a thermal head placed opposite to the platen roller, and the ink of the ink sheet is transferred to the recording paper. A capstan roller for conveying recording paper is provided downstream of the platen roller, the platen roller is driven by a DC motor, the capstan roller is driven by a stepping motor, and the DC motor is started. A thermal transfer recording apparatus characterized in that the stepping motor is started after a predetermined period of time has elapsed.