JPH0777817B2 - Inking device for thermal transfer printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inking device for reusing an ink holder so that it can be repeatedly used in a printer using a thermal transfer system.

[Conventional technology]

FIG. 4 is a side view showing an example of a conventional thermal transfer printer.

As shown in FIG. 4, a thermal transfer type printer capable of recording on plain paper using a thermal head has a relatively low melt transfer in which a coloring amount such as a pigment is added to a heat-melting binder material such as ester wax. Ink ribbon 201 with ink applied on polyester film is reel 202 beforehand.
The ink ribbon 201 is wound on a sheet of paper 12 wound around a thermal head 118 and a platen 120 in which a plurality of heating elements are arranged in series from a reel 202 via a guide roller 104.
1 and by applying an appropriate pressure between the thermal head 118 and the platen 120 to heat an appropriate heating element corresponding to the printed characters of the thermal head 118, the ink in the corresponding portion of the ink ribbon 201. Is melted and transferred, and the used ink ribbon 201 is wound on the reel 203. Such a thermal transfer printer can print not only on plain paper but also on resin-based materials such as polyester film such as OHP film.

[Problems to be Solved by the Invention]

The ink ribbon of the conventional thermal transfer printer as described above cannot be reused, and the ink that is not used for printing is discarded because it is unused and is uneconomical. Has the disadvantage of high costs. Further, since it is necessary to provide a space for the reel for winding the ink ribbon inside the printer, there is a problem that the printer becomes large.
In addition, since the printed characters remain on the used ink ribbon in a reversed form, a third party can easily know the printed contents, which causes a problem of confidentiality. Furthermore, there is a drawback that the number of dots that can be printed at one time is smaller than that of other printing methods such as a wired printer.

In order to solve such a problem, the ink ribbon is changed to a belt-shaped ink holder having heat resistance and durability, ink is supplied to this to form a thin film of ink on the surface, and the thermal head is used to form it. An inking device of a system in which the ink is transferred onto a recording sheet and the remaining ink is collected by an ink holder has been announced (see Japanese Patent Laid-Open Nos. 62-48594 and 62-56177). All of these devices supply ink to the ink holder by immersing the ink holder in a large ink container, or by immersing a rotating roller and sandwiching it with a pressure roller, and removing excess ink with a knife. The method of removing by the edge is adopted. Since such an inking device has a pressure roller and a knife edge, a large load is applied when the ink holder is moved and a large capacity is required for immersing the ink holder or the rotating roller. There is a problem that an ink container is necessary and its arrangement is limited, which is a major obstacle to practical use.

An object of the invention is to provide an inking device for a thermal transfer printer that solves the above problems.

[Means for Solving the Problems]

An inking device for a thermal transfer printer of the present invention is a cylinder or a circle formed by a heat-resistant material, which is rotated while being in contact with an ink holder to form a rough surface for forming an ink film on the surface of the ink holder. A columnar inking roller,
Inking for a thermal transfer printer including a sub-inking roller that contacts the ink holder and rotates in a direction opposite to the moving direction of the ink holder, and an ink chamber that stores ink and supplies the ink to the inking roller In the apparatus, a housing having a partial cylindrical surface-shaped contact surface having an inner diameter slightly larger than the diameter of the inking roller, which is in contact with the inking roller so as to wrap, is provided, and an ink chamber for storing ink in the housing, Each of the rollers, a housing, and a heater for heating to melt ink in the ink chamber are provided. Further, the sub-inking roller is arranged so as to come into contact with the inking roller via ink, and the housing has a contact surface which comes into contact with the sub-inking roller.

[Action]

An inking device for a thermal transfer printer according to the present invention includes a partially cylindrical surface having an inner diameter slightly larger than a diameter of an inking roller provided in a housing, which is obtained by melting a thermally fusible ink in an ink chamber with a heater, and an inking roller. The ink is applied to the belt-shaped ink holder by adhering the ink to the surface by a minute gap and rotating the inking roller to bring the ink holder into contact with part of the surface to form an ink film. Then, this is formed into a film having a smooth and uniform thickness by an inking roller.

〔Example〕

 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

In FIG. 1, a rotatable cylindrical (or cylindrical) inking roller 900 formed of an aluminum alloy.
Has a length substantially the same as the width of the ink holder 701, that is, the width of the recording paper. Also, its surface is
In order to make it easy for ink to adhere, it is surface-treated in a satin finish by a sandblast method or the like. Instead of performing the satin-like surface treatment, narrow grooves may be provided along the axial direction or the circumferential direction. The linear heating element 902 of the same length provided inside the inking roller 900 to heat it is composed of a hologen lamp or a ceramic heater. The heating element 902 need not rotate with the inking roller 900. The inking roller 900 is associated with a partial cylindrical surface 905 provided on the housing 904. The radius of the circular arc of this cylindrical surface 905 is slightly (about 0.5 mm or less) larger than the radius of the inking roller 900, and therefore a minute gap 906 is formed by combining them. Housing 9
The ink 908 melted by the heater 907 provided in 04,
The supply path 909 provided in the housing 904 by the surface tension
It is supplied to the minute gap 906 via. The ink 908 supplied to the minute gap 906 adheres to the surface of the rotating inking roller 900, is guided by the guide roller 901, and is transferred to the surface of the ink holding body 701 which runs while contacting the upper portion of the inking roller 900. To do. The ink 908 transferred to the ink holder 701 has a rough film surface due to a phenomenon called tack due to the surface roughness of the inking roller 900 and the viscoelasticity of the ink 908, which causes uneven printing density. This may cause print quality deterioration such as character fading due to transfer failure. Therefore, the sub inking roller 903 provided adjacent to the inking roller 900 and heated by the inking roller 900 squeezes the surface of the ink film 910 transferred to the ink holding member 701 to smooth the ink film 910. And make the thickness uniform.

FIG. 2 is a cross-sectional view showing a transfer state of ink to the ink holder in the embodiment of FIG.

In FIG. 2, there is a residual ink film 808 transferred by printing on the recording paper side surface of the ink holder 701.
It contacts the portion 801 of the inking roller 900 and is heated and melted by the inking roller 900, at the same time,
Ink 908 newly attached to the surface of the inking roller 900
To form a new ink film 910. At this time, the film thickness becomes uneven due to the roughness of the surface of the inking roller 900 and the tack phenomenon in the portion 801. In order to remove the unevenness of the film thickness, the ink holding body 701 is brought into contact with the sub-inking roller 903 which rotates in a direction opposite to the moving direction of the ink holding body 701 in synchronization with the inking roller 900 by a transmission means such as a gear. This allows the ink film 8
02 is melted again, and a uniform molten ink layer 805 is formed between the sub inking roller 903 and the ink holder 701. The height of the molten ink layer 805 is determined by the surface pressure proportional to the tension of the ink holder 701 and the viscosity of the ink. The excess ink 806 is moved toward the inking roller 900 by the sub-inking roller 903 that rotates in the direction opposite to the moving direction of the ink holding body 701, and is collected. At this time, the residual ink 8 remaining on the sub inking roller 903
The movement of 06a is stopped by the portion 804 of the housing 904 that is in contact with the sub inking roller 903, and finally 06a is collected in the housing 904. Inking roller 9
Of the ink 908 attached to the surface of 00, the ink 807 that has not transferred to the ink holder 701 is also collected in the housing 904. As a result, a smooth ink film 901 having a uniform thickness is formed on the surface of the ink holder 701. According to an experiment by the inventor, it was possible to form a smooth and uniform ink film having a thickness of 10 μm.

FIG. 3 is a side view showing an example of a thermal transfer printer using the embodiment of FIG.

In FIG. 3, an ink holding member 701 is circulated by a feed roller 704 and a plurality of guide rollers 703, and an inking device 70 disposed in the middle of its movement path.
Passing 5. On the other hand, the recording paper 70 placed on the hopper 704
8 is sent out one by one by the pickup roller 709, proceeds along the path shown by the broken line in the figure, and is sent to the stacker 710 through between the backup roller 702 and the ink holding body 701 in contact with the thermal head 706. . By making the feed roller 704 a metal roller having good thermal conductivity and easily radiating heat to the outside, cooling and solidification of the ink on the ink holding body 701 supplied by the inking device 705 is promoted. Ink holder
The 701 can run at high speed, and thus a thermal transfer printer capable of high-speed recording can be obtained.

Although the example of FIG. 3 is an example in which the present invention is applied to a line printer type thermal transfer printer, it can be easily applied to a serial printer type thermal transfer printer.

〔The invention's effect〕

As described above, the thermal transfer printer inking device of the present invention has an effect that a large load is not applied when the ink holding body is running. Further, since there is no need for a large-capacity ink container, there is an effect that restrictions on the arrangement of the ink container can be relaxed. Therefore, there is an effect that the thermal transfer printer which is excellent in economical efficiency and can perform high-speed recording can be obtained by efficiently transferring the ink onto the recording paper.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view showing the transfer state of ink to the ink holder in the embodiment of the figure, FIG. 3 is a side view showing an example of a thermal transfer printer using the embodiment of FIG. 1, and FIG. 4 is a conventional thermal transfer printer. It is a side view which shows an example. 104/901 ... Guide roller, 118/706 ... Thermal head, 120 ... Platen, 121 ... Paper, 201 ... Ink ribbon, 202/203 ... Reel, 701 ... Ink holder, 702
…… Backup roller, 703 …… Guide roller, 704…
... Feeding roller, 705 ... Inking device, 707 ... Hopper, 708 ... Recording paper, 709 ... Pickup roller, 710
…… Stacker, 801/804 …… part, 802/808/910 ……
Ink film, 805 ... Molten ink layer, 806/807/908 ... Ink, 806a ... Residual ink, 900 ... Inking roller, 902 ... Heating element, 903 ... Sub inking roller, 90
4 ... Housing, 905 ... Cylindrical surface, 906 ... Minute gap, 9
07: heater, 909: supply path.

Claims (2)

[Claims] 1. A cylindrical or columnar inking roller which rotates while contacting with an ink holder to form an ink film on the surface of the ink holder with a rough surface and made of a heat-resistant material. An ink for a thermal transfer printer including a sub-inking roller that contacts the ink holder and rotates in a direction opposite to the moving direction of the ink holder, and an ink chamber that stores the ink and supplies the ink to the inking roller. In the king device, a housing having a partially cylindrical surface-shaped contact surface having an inner diameter slightly larger than the diameter of the inking roller, which is in contact with the inking roller so as to surround the inking roller, is provided, and an ink chamber for storing ink in the housing is provided. And a heater for heating the rollers and a heater for melting the ink in the housing and the ink chamber. For copy printer inking equipment. 2. The sub-inking roller is arranged so as to come into contact with the inking roller via ink, and the housing has a contact surface which comes into contact with the sub-inking roller. An inking device for a thermal transfer printer according to 1.