JPH0441268A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer printer reproducible quality printing and to reduce costs for parts in manufacturing the same by a method wherein a sheet-holding roller that holds a sheet of recording paper is made of a shaft that is made by stepped drawing and is covered with a shrinkable tube that is made of fluorine elastic material and is applied to the surface of the roller by shrinkage pressure-fitting or shrinkage sticking. CONSTITUTION:A first sheet-feeding roller 20 is made of a round metal bar and is formed by stepped drawing. Coating with metal powder or ceramic is applied to the surface of said roller by flame spraying or adhesion. The opposite ends of the roller are supported with bearings, and rotational driving of a sheet-feeding gear 10 is transmitted to one end of the roller. A first sheet-holding roller 22 is made of a metal shaft 22-a formed by stepped drawing with a heat-shrinkable fluorine tube 22-b stuck thereon after shrinkage. As the metal shaft 22-a is covered with the heat-shrinkable tube 22-b, edges of the metal shaft are made in large radius, and thereby concentration of pressure around the edges can be relieved. By using the fluorine heat-shrinkable tube as the material for the sheet-holding roller rubber 22-b, transfer of ink after the recording can be prevented, and thereby deterioration of printing quality or greasing can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer printer that heats and melts a thermal transfer ink ribbon using a recording head and transfers the ink ribbon onto recording paper.

[Prior Art] A thermal transfer printer shown in FIG. 4 has been known in the prior art.

An ink ribbon 32 supplied from a recording paper 30 and a supply core 31 is compressed by a recording head 33 and a platen 34 made of rubber, and recording is performed by the heat generated by the recording head 33.

After recording, the ink ribbon 32 is peeled off from the recording paper 30 at the position of the ribbon peeling roller 35 pressed against the platen 34 and wound around the winding core 36.

The recording paper 30 is conveyed in the direction indicated by the arrow in the figure while being compressed by a paper feed roller 37 and a paper press roller 38.

When recording is completed, the recording head 33 and ribbon peeling roller 35 are separated from the platen 34, and the recording paper 30 is ejected by the paper feed roller 37 and paper presser roller 38, completing the series of recording operations.

Next, FIG. 5 shows a partial cross-sectional view of the vicinity of the paper feed roller 37 and paper press roller 38 related to the paper conveyance system.

The paper feed roller 37 has a metal shaft coated with metal powder, ceramic, etc. by thermal spraying to give a high friction treatment to the surface, and the paper press roller 38 has NBR or EP coating around the metal shaft 38-a.
The DM rubber 38-b is formed by molding or adhesion.

[Problems to be Solved by the Invention] However, regarding the paper press roller 38 in the conventional thermal transfer printer, the rubber 38-b such as NBR or EPDM is baked around the metal shaft 38-a by molding or molding. Since it is manufactured by adhesion, the cycle time becomes long and the cost is also high.

In addition, pressure concentrates near the edges of the surface of the rubber 38-b, damaging the recording surface of the recording paper 30, and furthermore, transferring ink recorded on the entire surface of the rubber 38-a, resulting in deterioration of recording quality and background stains. There was a problem of causing it.

SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional problems and to provide a thermal transfer printer that reduces component costs and has good recording quality.

[Means for Solving the Problems] In a thermal transfer printer that heats and melts a thermal transfer ink ribbon in a recording head and transfers it to a recording paper, the recording paper is placed opposite to a paper feed roller serving as a main conveyance means when the recording paper is conveyed. The paper press roller that presses the paper is formed by shrinking and pressing or shrinking and adhering a shrinkable tube around a stepped paper press roller shaft, and the tube is made of a fluorine-based elastic material. It is characterized by

[Embodiment] An embodiment of a thermal transfer printer capable of monochrome and color thermal transfer recording according to the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram of a thermal transfer printer according to the present invention during monochrome and color thermal transfer recording.

First, monochrome thermal transfer recording will be explained with reference to FIG.

When a recording start signal is input, a plurality of sheets of recording paper 2 set in the hopper L are rotated counterclockwise by a feed roller 3 made of a rubber material with a high coefficient of friction, and are moved along the upper surface of a paper guide 4 to the right in the figure. Paper is fed in the direction. Furthermore, the paper path selection plate 5 that overlaps with the upper surface of the paper guide 4 is pushed up by its own weight, and after passing through the BOF sensor 6 which is the detection means of the recording paper 2, the second paper feed roller 7, which is stationary and in a pressed state, and the second The recording paper 2 collides with the paper presser roller 8 and comes to rest in a slightly buckled state.
Align the tips of the

Immediately after this, the stepping motor 9 starts rotating, the rotation is transmitted to the second paper feed roller 7 via the paper feed gear 10, and the ink ribbon is stored in the platen 11 and the ink ribbon cassette 12.
After the recording paper 2 is conveyed by a predetermined number of steps between the recording heads 15 which obtain a pressing force by a head pressure spring 14 via the supported thermal transfer ink ribbon 13,
The hopper 1 on which the recording paper 2 is loaded is separated from the feed roller 3, and the monochrome paper feeding operation is completed.

At two points, a platen pressure roller 16 that presses and releases the platen 11 and the recording head 15 of the platen 11
The pose position is the pose state shown in FIG. 2(a) and the position indicated by the two-dot chain line in the figure.

The recording operation then begins, and the platen pressure roller 16, whose rotating shaft is eccentric to the central axis, receives driving force from a DC motor (not shown), and the platen 11 moves to the position shown by the solid line, as shown in FIG. 2(b). It stands still in the pose state and at the position shown by the solid line in the figure. A constant pressure is applied to the recording head 15 through the recording paper 2 and the thermal transfer ink ribbon 13, power supply to the recording head 15 is started, and recording is executed.

During this recording, the thermal transfer ink ribbon 13 is transported by a train of wheels including a paper feed gear 10, a l/bon reduction gear A 17, a ribbon reduction gear B 18, and a ribbon gear 19, using a stepping motor 9 as a ribbon drive means as a drive source. conduct. In other words, the driving source for feeding the recording paper 2rj and the driving source for feeding the thermal transfer ink ribbon 13 are shared.

Further, drive transmission to the thermal transfer ink ribbon 13 is performed by engaging a notch provided in the ribbon core 13-a with a protrusion of the ribbon gear 19.

As recording progresses, the leading edge of the recording paper 2 comes to rest with the first paper feed roller 20, which serves as the main paper transport means during color recording, in the pause state shown in FIG. 2(b) and at the position indicated by the two-dot chain line in the figure The paper passes between the first paper pressing roller 22 and the first paper holding roller 22, is guided by a paper discharge guide 23 fixed above it, and is conveyed between paper discharge rollers 24 that rotate counterclockwise.

When recording is completed, the platen 11 and the first paper presser roller 2
2 moves to the position shown in FIG. 2(a) and the two-dot chain line,
Due to the counterclockwise rotation of the paper ejection roller 24, the stacker 25
The recording operation is completed.

Here, the stacker 25 performs face-down cooking in which the recording paper 2 is stacked with the recording surface facing down by tilting it in the direction of arrow A in the figure, and stacking the recording paper 2 with the recording surface facing up by tilting it in the direction of arrow B in the figure. It is possible to form two states of face-up stacking.

Next, color thermal transfer recording will be explained.

The paper feeding operation of the recording paper 2 is carried out from the hopper 1 to the second paper feed roller 7.
The steps up to this point are the same as those for monochrome thermal transfer recording, and the recording paper 2, buckled and stationary by the second paper feed roller 7 and the second paper press roller 8, is moved to the paper feed gear 1 using the stepping motor 9 as the driving source.
After the recording paper 2 is conveyed several times by the counterclockwise rotation of the second paper feed roller rough that obtains the driving force via the hopper 1 on which the recording paper 2 is stacked, the hopper 1 separates from the feed roller 3.

Further, as the second paper feed roller 7 rotates, the platen 11 in the pose state shown in FIG. The paper passes between the recording head 15 which is biased by a pressing force 14, and is conveyed between the first paper press roller 22 and the first paper feed roller 20. Further, the leading edge of the recording paper 2 is guided by the paper discharge guide 23 and detected by the TOF sensor 26, which is recording paper leading edge detection means, and the rotation of the stepping motor 9 is stopped. Here, Fig. 2(d)
The recording paper 2 is gripped by the first paper presser roller 22, and in order to minimize the recording start position on the recording paper 2, the stepping motor 9 is reversed and the recording paper 2 is gripped.
The paper is returned to the contact area between the first paper feed roller 20 and the first paper press roller 22, which are the main paper transport means. This completes the paper feeding operation of the recording paper 2, and then moves on to the recording operation.

Color recording starts from this point, but first the color thermal transfer ink ribbon 13 is located. Thermal transfer ink ribbon 13 for color recording is coated with heat-melting ink in yellow, magenta, and cyan in order.Transparent portions are provided at the boundaries of each color to identify the beginning of the ink, and the transparent portions at the beginning of each color are provided. Black markings of different shapes are placed on each section, and these are detected by a reflective marker sensor (not shown) to locate the beginning of the ribbon. To transport the ribbon at the beginning of the ribbon, the rotation of the DC motor 27 is controlled by the ribbon reduction gear C28, the ribbon reduction gear D29, and the ribbon gear 1.
9 and starts winding at a speed higher than the recording speed. During this ribbon cueing, the ribbon reduction gear 18, which is the ribbon drive means during recording, is released from the gear train with the ribbon gear 19 by a drive release means (not shown).

When the ribbon cue for the first color is completed, the pause state changes to the second color.
The state shifts to the state shown in FIG. 3(C), and the recording head 15 is energized and recording of the first color is started. At this time, the thermal transfer ink ribbon 13 is conveyed by the stepping motor 9. Note that during recording, the wheel train for transmitting drive from the DC motor 27 is released.

When the recording of the first color is completed, the state shifts to the state shown in FIG. 2(d), and paper return begins, and when the leading edge of the recording paper 2 passes the T○F sensor 26 and returns to the recording start position of the - color, the stepping motor Although the rotation of the thermal transfer ink ribbon 9 is stopped, the second color cue of the thermal transfer ink ribbon 13 is being executed at the same time as the paper return operation. After this, the pause state returns to the state shown in FIG. 2(C) and the second color recording begins. Thereafter, recording of the third color is executed in the same manner. When the sequential recording of the three color planes is completed in this way,
The state shifts to the state shown in FIG. 2(a), and the ejecting operation of the recording paper 2 similar to that for monochrome recording is performed, and color recording is completed.

Furthermore, this thermal transfer printer can perform thermal recording using thermal paper as the recording paper 2 by detaching the ink ribbon cassette 12 containing the thermal transfer ink ribbon 13 from the thermal transfer printer main body. Thermal recording is performed using the same sequence as the monochrome thermal transfer recording described above except for the thermal transfer ink wafer 13.

The outline of the recording operation of the thermal transfer printer according to the embodiment of the present invention has been described above, and FIG. 3 shows a detailed sectional view of the main paper conveyance system.

The first paper feed roller 20 is formed by thermally spraying or adhering metal powder or ceramic to the stepped surface of a metal round bar. Both ends are supported by bearings, and one of the rollers further rotates the paper feed gear 10. Drive is transmitted.

The first paper pressing roller 22 is formed by bonding a fluorine-based heat shrinkable tube 22-b to a stepped metal shaft 22-a in the shape shown in the figure after shrinking.

Here, since the heat-shrinkable tube 22-b is stacked on the metal shaft 22-a, a large radius is obtained at the edge portion, and pressure concentration near the edge is reduced.

Furthermore, if the torsional torque applied to the fluorine-based heat-shrinkable tube 22-b is small, it may be attached to the metal shaft 22-a by simply shrinking it without adhesion.

Furthermore, in this embodiment, the paper pressing portion of the metal shaft 22-a is
Although the locations are set, this does not apply even if the locations are formed at two or more locations.

In addition, by using a fluorine-based heat shrinkable tube for the paper press roller rubber 22-b, compared to the case of rubber materials such as NBR or EPDM, it is possible to prevent ink transfer after recording, resulting in deterioration of recording quality or background stains. Prevention has been achieved.

The actual paper conveyance by the above-described paper conveyance means is to move the recording paper 2 inserted onto the first paper press roller 20 to the first paper press roller 20.
2 and rotation of the first paper feed roller 22 performs frictional conveyance.

[Effect of the invention 1] The thermal transfer printer of the present invention has a first paper presser roller formed by stacking fluorine-based heat shrinkable tubes on a stepped metal shaft, thereby achieving a very simple manufacturing process and reducing manufacturing cycle time. Ta. In addition, by using inexpensive fluorine-based heat-shrinkable tubes that have a small material volume and are ready-made for general use, there is no need to bake or mold fluorine-based rubber, which is effective for removing dirt but has high material costs, from the material level, reducing costs. It also showed a significant effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a thermal transfer printer according to an embodiment of the present invention. FIG. 2 is a pose state diagram of a thermal transfer printer according to an embodiment of the present invention. FIG. 3 is a detailed sectional view of the paper conveyance system according to the present invention. FIG. 4 is a schematic diagram of a conventional thermal transfer printer. FIG. 5 is a detailed sectional view of a conventional thermal transfer printer.・Thermal transfer ink ribbon ・Recording head ・First paper feed roller ・First paper presser roller and above Applicant Seiko Epson Corporation Representative Patent Attorney Kizobe Suzuki fI! ! 1 person 2... Recording paper 11... Platen Figure 3 Figure 4

Claims (2)

[Claims] (1) In a thermal transfer printer that heats and melts a thermal transfer ink ribbon with a recording head and transfers it to a recording paper, when the recording paper is conveyed, the recording paper is held down in opposition to a paper feed roller that serves as the main conveyance means. A thermal transfer printer characterized in that the paper press roller is formed by shrinking and pressing or shrinking and adhering a shrinkable tube around a stepped paper press roller shaft. (2) The thermal transfer printer according to claim 1, wherein the tube is made of a fluorine-based elastic material.