JPS62124980A - Thermal transfer recording method - Google Patents

Abstract

PURPOSE:To obtain a thermal recording method which does not require a thermal transfer material and is low in recording cost, by supplying heat patternwise directly to the outer peripheral surface of a porous ink roll impregnated with a thermally transferable ink. CONSTITUTION:An ink roll 3 comprising a porous material 2 impregnated with a thermally transferable ink 1 at the outer peripheral surface thereof is supported by springs 4 at the axis thereof, and is rotated in the direction of an arrow A. When heat is supplied patternwise according to a desired image signal from a thermal head 5 to the outer peripheral surface of the roll 3, the ink 1 present at the peripheral surface is thermally melted or softened to become sticky. The peripheral surface of the ink roll 3 is brought into contact with a recording medium 6 being fed in the direction of an arrow B at a transferring position. At this time, under a pressure exerted by a platen 7, the ink 1 remaining in the sticky state in a pattern form is transferred onto the medium 6 under pressure, forming a transferred record image 8. The ink 1 in the inside part of the roll 3 is supplied to the peripheral surface by capillarity or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer recording method that reduces recording costs by eliminating the need for conventionally used thermal transfer materials.

The thermal transfer recording method, which is widely used as a method for recording on plain paper, generally involves dispersing a colorant in a heat-melting binder onto a sheet-like support. Using a heat-sensitive transfer material coated with ink, heat is supplied from the support side of the heat-sensitive transfer material using an external heating member such as a thermal head, or a voltage is applied to the conductive support or ink layer to generate a joule. By causing the conductive support or the ink layer itself to generate heat (Japanese Unexamined Patent Application Publication No. 1989-1999)
8-220795, JP-A-58-12790, etc.) By selectively transferring melted ink to a recording medium, a transferred recorded image is formed on the recording medium according to the shape of heat supply. be.

However, in the conventional thermal transfer recording method, a thermal transfer material is used in which a thermal transferable ink layer is formed on a relatively expensive heat-resistant plastic film support through a complicated process, and this thermal transfer material Because it is made of wood and is disposable, it has the disadvantage of increasing the cost of thermal transfer recording. Furthermore, when patterned heat is applied to the heat-sensitive thermal transfer material from the support side, a loss of thermal energy occurs due to heating of the heat-transferable ink layer through the support.

In order to reduce the recording cost of thermal transfer recording method,
It is also possible to use an endless belt or drum-shaped support that can be used repeatedly, coat and form a thermal transfer ink layer on the support on the spot, and use it as it is for thermal transfer recording, but in this case, Since it is necessary to incorporate a complicated ink application mechanism into the thermal transfer device to form an ink layer of uniform thickness on the support, there is a problem that the device becomes complicated and large.

Separately, as a thermal transfer recording method that eliminates the need for the thermal transfer material, patterned heat is applied via a recording medium to an ink roll made of porous sintered metal impregnated with thermal transfer ink. It has been proposed to form a transferred recorded image on a recording medium by
-178784).

However, in this case, since patterned heat is applied through a relatively thick recording medium of approximately 50 to 1,100 IL, the loss of patterned thermal energy not only increases more than when using conventional thermal transfer materials. Since the heating pattern spreads due to thermal diffusion inside the recording medium, the resolution becomes insufficient and a clear recorded image cannot be obtained.

The main object of the present invention is to eliminate the drawbacks of the conventional thermal transfer recording methods mentioned above, maintain various thermal transfer performances, and use a compact device to reduce the recording cost and produce patterned patterns. An object of the present invention is to provide a thermal transfer recording method that allows effective use of thermal energy.

As a result of research for the above-mentioned purpose, the inventors of the present invention have found that by directly applying heat or voltage to the outer circumferential surface of an ink roll, the outer circumferential surface of which is made of a porous material impregnated with thermal transferable ink. After imparting a pattern of adhesiveness to the thermal transfer ink, it is possible to transfer the thermal transfer ink to a recording medium by pressure while the adhesive pattern is maintained, while using a compact thermal transfer device. The present invention makes it possible to use the above-mentioned ink roll stably for a long time in place of the expensive heat-sensitive transfer material that has been used, and reduces the cost of heat-sensitive transfer recording.
It has been found that the loss of thermal energy caused by conventional patterned heat supply through a support is eliminated, and it is extremely effective in achieving the above object.

The thermal transfer recording method of the present invention is based on such findings, and more specifically, the thermal transfer recording method of the present invention is based on the above findings. A step of selectively melting or softening the thermal transfer ink by applying a voltage, and bringing the outer peripheral surface of the ink roll into contact with a recording medium, and pressing the thermal transfer ink in a melted or softened state according to the pattern onto the recording medium. The special feature is that it consists of a step of transferring.

Hereinafter, the present invention will be explained in more detail with reference to the drawings as necessary. In the following descriptions, "%" is used to express quantitative ratio.
” and “parts” are based on weight unless otherwise specified.

・Snow Figure 1 shows an embodiment of the present invention in the case where a thermal head is used as a source of heat to melt or soften the thermal transfer ink (hereinafter, this heat supply method is referred to as "r thermal head method"). FIG. 2 is a schematic cross-sectional view in the thickness direction of a recording medium.

Referring to FIG. 1, an ink roll 3 whose outer peripheral surface is made of a porous material 2 impregnated with a thermal transferable ink 1 is disposed with its center held by a spring 4, and is arranged continuously or intermittently in the direction of arrow A. rotate.

On the other hand, when heat in a pattern corresponding to a desired image signal is supplied to the outer circumferential surface of the ink roll 3 from the thermal head 5 disposed opposite the outer circumferential surface on the right side of the ink roll 3 rotating as described above, The thermally transferable ink l present on the outer circumferential surface is thermally melted or thermally softened according to the heating pattern described above, and at the same time becomes sticky, and has transferability to the recording medium. It moves upwards in the figure as it rotates.

While the adhesive pattern of the thermal transferable ink corresponding to the heat supply shape is maintained, the outer peripheral surface of the ink roll 3 is made of plain paper or the like at the transfer position, and the recording material is transferred in the direction of arrow B. The thermal transfer ink 1 contacts the medium 6, but at this time, under pressure from the platen 7 facing the ink roll 3 with the recording medium 6 in between, the thermal transfer ink 1 that maintains the above-mentioned patterned adhesive state is transferred to the recording medium. 6 to form a transferred recorded image 8.

After the above transfer process is completed, the ink roll 3 further rotates in the direction of arrow A from the transfer position, but at the downstream of this ink transfer position, the thermal transfer ink 1 inside the ink roll 3
is supplied to the outer peripheral surface of the ink roll 3 by capillary action, centrifugal force, gravity, etc., the impregnated state of the thermal transferable ink 1 on the outer peripheral surface is regenerated, and the ink is subjected to the series of steps described above.

In order to smoothly supply the thermally transferable ink 1 to the outer peripheral surface of the ink roll 3, a heater 9 is disposed inside the ink roll 3, and a heater 9 is arranged inside the ink roll 3 to supply the thermally transferable ink 1 inside the ink roll 3.
It is preferable to impart desired fluidity to the ink 1 by heating the ink.

When arranging the heater 9 as described above, if necessary,
The cooling means 10 may be arranged to face the outer circumferential surface of the ink roll 3 on the upstream side of the heating pad 5.

Next, the configuration of each part shown in the drawings will be explained.

The ink roll 3 is a member having a rotating body shape such as a cylinder or a truncated cone, and is made of a porous material 2 impregnated with the thermal transferable ink 1 at least on its outer peripheral surface.

The thermal transfer ink 1 is made by dissolving or dispersing a coloring agent such as a dye or a pigment in a heat-melting binder.

As the heat-melting binder, various binders conventionally used such as natural or synthetic waxes and resins can be used alone or in combination of two or more.

As this heat-melting binder, a heat-melting binder having supercooling property (hereinafter referred to as "supercooling heat-melting binder") is used.
), the thermal transfer ink 1 maintains a melted or softened state for a certain period of time even after the heat application is completed, so that the process from the process of applying heat to the ink roll 3 by the thermal head 5 to the process of transferring the ink to the recording medium 6 This is preferable because the time required for the transfer process can be varied, and the rotational speed of the ink roll 3 or the printing speed in the transfer process can be easily controlled. Moreover, if this supercooled thermofusible binder is used, it becomes easier to supply the thermally transferable ink l to the outer circumferential surface of the ink roll 3 described above.

Here, the supercooled thermofusible binder refers to a binder that, when once heated above the melting point and cooled from the molten state, maintains the above-mentioned molten state for a certain period of time even at a temperature below the original melting point.

For binders that do not exhibit a fixed melting point, "softening point" is used instead of "melting point" and "softening" is used instead of "melting".

Such a supercooled thermofusible binder is, for example, a plasticizer such as N-cyclohexyl-p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, or synchrohexyl phthalate, which is a known supercooling substance, or benzene. Triazole, acetanilide, etc., or their derivatives alone or in combination of two or more,
Thermoplastic resins used in conventional thermal transfer inks such as polyamide resins, polyacrylic resins, polyvinyl acetate resins, or copolymers thereof (preferably those with a softening point of 40 to 230'C by the ring and ball method!), and Preferably 50
~200° C.), various natural or synthetic waxes, etc., by mixing with a conventional heat-melting binder.

In this case, for example, 20 to 90 parts of the above-mentioned supercooled substance may be mixed into 10 to 80 parts of the above-mentioned conventional hot-melt binder.

In addition to the above-mentioned supercooled thermofusible binders, there is also one example of the supercooled thermofusible binder described in the applicant's previous application (Japanese Patent Application No. 173984/1984, 1983).
The supercooled thermofusible binder used in the invention related to the invention titled "Thermal Transfer Material" (filed on August 9, 2013) is also preferably used. This supercooled thermofusible binder contains 5% or more of an unsaturated polyester composed of fumaric acid or maleic acid and glycol based on the entire binder.

Adding an oil or the like to these supercooled hot-melt binders to adjust their supercooling properties, or adding elastomers or the like to these or ordinary hot-melt binders to adjust melt viscosity, adhesive strength, etc. is also possible.

As the coloring agent that constitutes the thermal transfer ink l together with the supercooled thermofusible binder or the ordinary thermofusible binder, for example, dyes and pigments commonly used in printing or other recording methods such as carbon black can be used. These dyes and pigments may be used alone or in combination of two or more. The content of the colorant is preferably 1 to 40% based on the ink 1.

On the other hand, the porous material 2 constituting the outer peripheral surface of the ink roll 3 may be any material that has heat resistance and strength that can substantially maintain the roll shape under the heating and pressurizing conditions used in the present invention. , can be used without any particular restrictions.

Specific examples of this porous material include ceramics such as alumina and zirconia, metals such as aluminum and zinc, heat-resistant resins such as polyurethane, polystyrene, and polyamide, and heat-resistant rubbers such as silicone rubber and fluororubber. However, from the viewpoint of suppressing the collapse of the heat application pattern on the outer peripheral surface of the ink roll 3, it is preferable to use a material with low thermal conductivity.

Among the above materials, when using ceramics and metals,
For example, it may be formed into a porous roll shape having pores of a predetermined diameter by compression and sintering. The pore diameter can be controlled by adjusting the compression and sintering processing conditions.

In addition, when heat-resistant resin or heat-resistant rubber is used, fine particles such as NaC1 or CaCO3 are dispersed in the resin or rubber and formed into a roll, and then water (in the case of NaC1) or hydrochloric acid (in the case of CaCo3) is dispersed. After removing the fine particles or dispersing an organic or inorganic blowing agent in the resin, etc., heat treatment and molding may be performed.

The porous material 2 used in the present invention is obtained by the method described above, and the opening pore diameter of the porous material 2 is 0.0.
5 to 50 pm, more preferably 0.1 to 10 pm. In addition, the ratio of the total area of the pore openings to any unit area of the outer peripheral surface of the porous material 2 formed into a roll shape (
The surface aperture ratio) is about 10 to 80%, and even 40 to 60%.
% is preferable.

In order to obtain the ink roll 3 used in the present invention, for example, the above-mentioned supercooled melt binder or ordinary hot melt binder, colorant, and additives are melt-kneaded using a dispersion device such as a 7-triter, and thermal transfer is carried out. The ink 1, or the ink in the form of a solution or dispersion, may be obtained and impregnated into the porous material 2 formed into a roll, with heating if necessary.

In addition, in order to prevent the melted or softened ink 1 from adhering to the heat transfer ink 5, a lubricant such as fatty acid amide or metal soap, or fine powder such as a high melting point resin or wax is added to the heat transfer ink 1. You may.

Furthermore, for color recording, it is also possible to use a plurality of ink rolls 3 having different tones.

The heater 9 is a member that heats the ink 1 inside the ink roll 3 to make it fluid in order to easily maintain a desired impregnated state of the thermal transferable ink 1 on the outer peripheral surface of the ink roll 3. .

This heater 9 is preferably placed inside the ink roll 3 (in the center of the ink roll, etc.), but instead of (or in addition to) the heater 9 inside this ink roll 3, a similar heater 9 may be used. (Not shown)
The desired impregnation state of the ink 1 may be maintained by imparting some fluidity to the thermal transferable ink 1 on the outer peripheral surface.

Moreover, instead of using these heaters, a small amount of thermal transferable ink 1 may be supplied to the outer circumferential surface of the ink roll 3 from outside while being heated.

The cooler 10 is a member arranged as necessary,
This is a member for keeping the thermally transferable ink l on the outer peripheral surface of the ink roll 3 in a non-adhesive state to the extent that it will not be transferred to the recording medium 6 (unless heat is applied by the thermal spatula 5).

The heating pad 5 is a member that supplies heat to the outer circumferential surface of the above-described ink roll 3 according to a desired image pattern.

As this thermal head 5, a conventional thermal head can be used as is, but in order to prevent the melted or softened ink 1 from the ink roll 3 that comes into direct contact with it from adhering, the heat generating part of the thermal head 5 is A coating of silicone resin or the like may be applied.

In the heat application by the thermal heater 5, as long as the outer peripheral surface of the ink roll 3 and the thermal head are in sufficient contact to apply heat in the desired pattern, the applied pressure may be 2 Kg/Cm2 or less, and the applied pulse Width is 0.5~5ms e c
The following conditions are preferably adopted.

By controlling the conditions for applying heat by the heating pad 5, it is also possible to change the amount of ink 1 transferred to the recording medium 6 and to obtain so-called half-tone recording on the recording medium.

The platen 7 is an elastic roll whose surface is made of rubber such as nitrile rubber, polyurethane rubber, ethylene propylene rubber, or natural rubber, or resin such as vinyl chloride resin or naron resin, or whose surface is made of metal, ceramics, etc. Any of the following rigid rolls may be used.

The pressure applied to the recording medium 6 between this platen 7 and the above-mentioned ink roll 3 is a linear pressure of 0.5 to 10 Kg/
cm, more preferably 1 to 5 Kg/Cm. From the viewpoint of sufficiently adhering the thermal transfer ink l to the four surfaces of the recording medium with poor surface smoothness, it is preferable that the pressure is large.

The distance between the transfer position where this platen 7 faces the ink roll 3 and the aforementioned thermal pad 5 is such that the thermal transfer ink 1 present in the porous material 2 on the outer peripheral surface of the ink roll 3 is
The intervals are set to maintain a desired pattern of melting or softening.

In the above, a typical embodiment of the thermal transfer recording method of the present invention has been described with reference to FIG. 1, but the present invention can be carried out in the same manner as in FIG. It is also possible to do so.

FIG. 2(a) is a schematic sectional view showing another aspect of such an ink roll 3.

Referring to FIG. 2(a), the porous material 2 of this ink roll 3 includes a porous material 2a made of a material with relatively low thermal conductivity that forms the outer peripheral surface of the roll, and a porous material 2a that forms the inside of the row layer. The porous material 2b is made of a material with relatively high thermal conductivity.

Among the materials for the porous material 2 described above, resins (polyurethane, etc.) or rubber (silicone rubber, etc.) are preferably used as the material with low thermal conductivity constituting the porous material 2a. It is preferable to use a material having the following properties in order to suppress wear on the surface of the thermal head 5. The distribution state of the open pores in this porous material 2a may be irregular, but it is better to have a regular distribution.
It is preferable from the point of view of improving the homogeneity of.

The layer made of porous material 2a preferably has a thickness of 0.1 to
Although this layer is formed to a thickness of about 10 mm, it is also possible to form this layer by, for example, pasting a porous film having a similar thickness, or by a spray method.

On the other hand, as the material with high thermal conductivity constituting the porous material 2b inside the roll, metals (aluminum, zinc, etc.) and the like are preferably used among the above-mentioned materials.

When using the ink roll 3 as shown in FIG. 2(a), the porous material 2b made of a material with high thermal conductivity is
Since the thermal transfer ink 1 can be easily heated to a substantially uniform temperature, the thermal transfer ink 1 maintains the desired fluidity almost uniformly from the inside of the ink roll 3 to near the surface, and the thermal transfer ink on the outer peripheral surface of the ink roll 3 maintains the desired fluidity almost uniformly. It becomes easier to maintain a homogeneous impregnated state of No. 1. On the other hand, due to the presence of the porous material 2a made of a material with low thermal conductivity, the solidification of the thermal transfer ink 1 maintained in a fluid state close to the surface on the outer circumferential surface of the ink roll 3 is promoted, and furthermore, the solidification of the thermal transfer ink 1 maintained in a fluid state close to the surface is promoted, and Deformation of the heat application pattern is effectively suppressed.

FIG. 2(b) is a schematic sectional view showing another aspect of the ink roll 3.

Referring to FIG. 2(b), this ink roll 3 is made of a hollow roll-shaped porous material 2. and thermal transfer ink 1 filled in the hollow portion. This hollow roll-shaped porous material 2 may have a multilayer structure as described in the configuration of FIG. 2(a).

When the ink roll 3 shown in FIG. 2(b) is used, the amount of thermal transfer ink 1 that can be stored in the one-wooden ink roll 3 increases, so one ink roll can be kept stable for a longer period of time. It is also easier to replenish ink during use.

In the above, an embodiment of the present invention has been described in which a thermal head method is used, that is, a thermal head is used as a heat source in the heat application process. , it will be readily understood that the present invention can be implemented in a similar manner.

Separately, as shown in FIG. 3(a), in place of the thermal head 5 shown in FIG. The electrode 5a and the conductive drum 11 can also be used in combination.

Referring to FIG. 3(a), a diagram of a conductive drum 11 is shown in which a metal conductive layer 11b having higher conductivity is provided on a low resistance layer 11a (specific resistance 10-10'Ω·cm). A recording electrode 5a facing the ink roll 3 is in contact with the low resistance layer 11a via the conductive drum 11, and this recording electrode 5a is connected to a return electrode 13 which is in contact with the metallic conductive layer 11b via the power supply 12. electrically connected.

In the configuration shown in FIG. 3(a), heat is applied in a pattern to the outer peripheral surface of the ink roll 3 by Joule heat generation in the low resistance layer 11a directly under the recording electrode 5a. Since the electrode 5a does not come into direct contact with the outer peripheral surface of the roll 3, there is less dirt on the electrode 5a, and the surface of the metallic conductive layer 11b can be easily cleaned. Other configurations are similar to those shown in FIG.

FIG. 3(b) shows another embodiment using the recording electrode 5a.

Referring to FIG. 3(b), a recording electrode 5a is placed on an ink roll 3a made conductive by dispersing conductive fine particles (not shown) in at least one of the thermal transfer ink 1 or the porous material 2. and the large-area return electrode 13a are in direct contact with each other. In the configuration shown in FIG. 3(b), the recording electrode 5
& At least one of the thermal transferable ink l on the outer peripheral surface of the conductive ink roll 3a directly below or the porous material 2 generates Joule heat, and the thermal transferable ink l melts or softens in a pattern. The configuration is almost the same as a).

As described above, according to the present invention, patterned heat or voltage is directly applied to the outer peripheral surface of the porous ink roll, which has an outer peripheral surface made of a porous material impregnated with thermal transferable ink. A thermal transfer recording method is proposed in which the ink in a melted or softened state corresponding to the pattern is then transferred under pressure to a recording medium.

The porous ink roll used in the present invention has excellent strength and heat resistance, and is resistant to deformation such as warping and waviness, and at the same time maintains the thermal transferable ink on its outer peripheral surface in a state suitable for applying patterned energy. Because it is easy to
It can be used stably for a long time without straightening the outer peripheral surface with a blade or the like.

Therefore, according to the recording method of the present invention, while using a compact thermal transfer device, the expensive thermal transfer material used in the past is not required, and the thermal transfer ink can be applied directly (without using a support). By supplying patterned heat, recording costs can be significantly reduced in terms of material and patterned energy costs.

Further, according to the present invention, it is possible to obtain high-quality printing even on a low-smoothness recording medium, and it is also possible to obtain half-tone recording by controlling the amount of heat applied in a pattern.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Carbon black lO part MA-11 (
(manufactured by Mitsubishi Kasei) Montan wax 20 parts (Hoechst φ
Wax Co., Ltd.) Low molecular weight oxidized polyethylene 10 parts (Allied)
(manufactured by Chemical Co., Ltd.) Paraffin wax 60 parts (manufactured by Nippon Jiro Co., Ltd.) The components shown above were mixed and stirred using a sand mill to obtain thermal transfer ink 1. This ink was impregnated into a roll-shaped porous metal 2 made of sintered aluminum and having a diameter of 60 mm (pore diameter: 10 Bm, surface aperture ratio: 60%) to obtain a porous ink roll 3.

Furthermore, using the thermal transfer device shown in FIG. 1 in which the distance between the thermal spatula 5 and the transfer position where the platen 7 faces the ink roll 3 is 2 cm, and the entire device is configured compactly, the thermal head 5 (applied pulse width: 1.1m5ec
) to apply heat directly to the outer peripheral surface of the ink roll 3 to soften the thermal transfer ink 1 in a pattern,
Linear pressure between ink roll 3 and platen 7: 5 Kg/
While applying a pressure of cm, the recorded image 8 was transferred onto pound paper 6 with a smoothness of 3 to 4 seconds using an Oken type smoothness tester.
was formed.

The recorded image on this pound paper is visually good in terms of print quality such as print density, transferability, clarity, etc., and the print quality is almost the same as when printed on high-quality deer paper with a smoothness of 120 seconds using the same method. Met. In addition, this thermal transfer recording does not use a conventional thermal transfer material, so the recording cost is low, and since heat is applied directly to the outer peripheral surface of the ink roll 3, the thermal energy consumption of the pattern is also low. Ta.

Further, by changing the applied pulse of the thermal heater 5, the amount of thermal transferable ink l transferred to the recording medium is changed,
Halftone recorded images could be obtained on the above-mentioned high-quality paper and pound paper.

Carbon black 10 parts (Printex, manufactured by Degussa) Polyamide resin 60 parts (Sunmide #55, manufactured by Sanso Kagaku Co., Ltd.) p-1 luenesulfonyl chloride 40 parts Ethyl acetate 300 parts Each component shown above Supercooled thermal transfer ink l (melting point 6) obtained by dispersing and mixing
When the same operation as in Example 1 was performed, except that the ink roll 3 was prepared using a dispersion liquid of 2°C), almost the same results as in Example 1 were obtained. It became easy to provide a time range between the process and the process of transferring to the recording medium 6, and it was possible to adjust the printing speed.

Furthermore, in the same manner as in Example 1, a halftone recorded image could be obtained.

[Brief explanation of drawings]

1, 3(a) and 3(b) are schematic cross-sectional views in the thickness direction of a recording medium showing embodiments of the thermal transfer recording method of the present invention, respectively, and FIG. 1 shows a thermal head 3(a) shows an embodiment using a recording electrode and a conductive drum in combination, FIG. 3(b) shows an embodiment using a recording electrode, and FIG. Figure (b
) is a schematic cross-sectional view showing another embodiment of the porous ink roll used in the present invention. ■... Thermal transfer ink, 2... Porous material, 3... Ink roll, 3a... Conductive ink roll, 4... Spring, 5... Thermal head, 5a... Recording Electrode, 6... Recording medium, 7... Platen, 8... Transfer recorded image. 9... Heater, 10... Cooler, 11... Conductive drum, 11a... Low resistance layer, 11b... Metallic conductive layer, 12... Power supply, 13... Return electrode. Figure 1 Figure 2

Claims (1)

[Claims] A step of selectively melting or softening the thermal transfer ink by applying patterned heat or voltage to the outer peripheral surface of an ink roll made of a porous material impregnated with the thermal transfer ink; and a step of selectively melting or softening the thermal transfer ink; A thermal transfer recording method comprising the steps of bringing a surface into contact with a recording medium and press-transferring thermal transfer ink in a melted or softened state according to the pattern onto the recording medium.