JPH0314631B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to image formation using a transfer recording medium whose physical properties governing transfer characteristics change when light and thermal energy are applied. The present invention relates to a photothermal recording head and a recording apparatus using the photothermal recording head.

<Prior Art> A thermal recording method is one of the recording methods used in conventional printers, facsimiles, etc. In this method, the ink layer of a sheet coated with thermal transfer ink is brought into contact with the recording paper that is the transfer target, and the sheet is selectively heated and melted using a thermal head that generates heat according to the image information. Image recording is performed by transferring ink to recording paper.

<Problems to be Solved by the Invention> However, the thermal recording method described above has the disadvantage that if the surface of the recording paper is not smooth, the ink cannot penetrate into the recording paper, resulting in a decrease in print quality. Since the transfer must be performed while pressing a platen roller or the like with a constant pressure, a head having a complicated pressing mechanism must be used.

In view of the above-mentioned drawbacks of the conventional methods, a method of recording by applying two or more types of energy to a transfer recording medium has been considered, but the structure of the head for applying two or more types of energy is complicated. There was a problem with the size of the device as it became larger.

SUMMARY OF THE INVENTION An object of the present invention is to provide a completely new photothermal recording head that solves the above-mentioned conventional problems, and a recording apparatus using the photothermal recording head.

<Means for Solving the Problems> The following means for solving the conventional problems described above includes a heating element, a light emitting element, and an optical waveguide that guides the light from the light emitting element onto or near the heating element. The present invention is characterized in that the photothermal recording head is constructed by providing the following.

<Function> According to the above means, thermal energy is applied to the transfer recording medium by the heating element that generates heat in response to the image signal, and optical energy guided from the light emitting element by the optical waveguide. It is.

<Example> Next, an example of a photothermal recording head to which the above-mentioned means is applied will be described.

FIG. 1 is a partially cutaway perspective view of a photothermal recording head A according to this embodiment, and FIG. 2 is a cross-sectional view. In the figure, reference numeral 1 denotes the substrate of the recording head A, which is made of alumina (Al ₂ O ₃ ), ceramic, etc., and a portion of the substrate 1 is coated with glass or crystallized material to reduce heat dissipation. A glaze layer 2 made of glass is provided.

Further, a plurality of electrodes 3 made of gold or copper are arranged in parallel on the upper surface of the glaze layer 2, and a heating element 4 is provided so as to span each electrode 3. The heating element 4 is made of an electrical resistor such as ruthenium oxide, and is arranged so as to straddle each of the electrodes 3, and is connected to a power source (not shown) connected to each of the electrodes 3. When a current flows between predetermined electrodes due to a pulse corresponding to an image signal, the heating element 4 between the electrodes through which the current flows generates Joule heat.

Next, reference numeral 5 denotes a light emitting body, which is disposed on the substrate 1 on the opposite side to the electrode 3, and is constructed by connecting a light emitting element such as an LED to the electrode 6. Reference numeral 7 denotes an optical waveguide for guiding the light emitted by the light emitting element 5 onto the heating element 4, which is made of transparent quartz glass, faces slightly upward in the vicinity of the heating element 4, 4. It is configured to cover the top surface. Further, the light emitting body 5 and the optical waveguide 7 are surrounded by a reflector 8 made of a glass material provided on the substrate 1.
By applying aluminum vapor deposition to the interface between the optical waveguide 7 and the optical waveguide 7, the structure is such that light is not radiated to others. Incidentally, the reflector 8 and the electrode 6 are insulated by an insulating material (not shown).

Next, a case will be described in which an image is recorded using the photothermal recording head A having the above configuration.

FIG. 3 is a schematic explanatory diagram of a recording apparatus using a photothermal recording head A, in which 9 is a transfer having a property that the melting temperature or softening point increases when irradiated with light in a state of being melted or softened by heat. Recording medium 9a
This is an ink/donor film in which a binder polymer, a crosslinking agent, a photoinitiator, a stabilizer, a colorant, etc. are arranged in a predetermined proportion, and is wound around a supply reel 10. The film 9 supplied from the supply reel 10 comes into pressure contact with the photothermal recording head A disposed opposite the platen roller 11, and negative information is formed by the head A.

That is, when a heat pulse corresponding to an image signal is transmitted from the control circuit 12 to the recording head A, the heating element 4 in a portion corresponding to the signal generates heat, and the transfer recording medium 9a of the film 9 is heated. Further, at this time, light is emitted from the light emitting body 5 at the same time as the heat pulse, and this light is guided by the optical waveguide 7 and is irradiated onto the transfer recording medium 9a on the heat generating body 4. As a result, optical energy and thermal energy are applied to the transfer recording medium 9a, and negative information is formed on the transfer recording medium 9a whose transfer characteristics change with these energies.

Next, the negative information is transferred onto the recording sheet 13 by a transfer means, which includes a heat roller 15 having a heater 14 inside, and a heat roller 15 disposed opposite the heat roller 15. A recorded image is transferred onto the recording sheet 13 by closely inserting the film 9 on which the negative information is formed and the recording sheet 13 between a pinch roller 16 that presses the roller 15.

In a recording device using a transfer recording medium whose transfer characteristics change depending on light and thermal energy as described above, the photothermal recording head of this embodiment is capable of supplying light and heat simultaneously and from the same direction. It is.

In the above embodiment, the light emitter 5 was provided in the reflector 8, but the end surface 7a of the optical waveguide 7 on the side of the light emitter 5 was polished, and the end surface 7a was polished as shown in FIG.
By disposing the light emitter 5 near the light emitter 5, the light energy of the light emitter 5 can be efficiently guided by the optical waveguide 7 without having to surround the light emitter 5 with the reflector 8.

Furthermore, in the above-mentioned embodiment, it has been explained that light energy is applied from the light emitter 5, but as shown in FIG.
b are arranged alternately, the red light emitting body 5a is controlled by the switch _S1 , and the green light emitting body 5b is controlled by the switch S2 _.
By configuring the transfer recording medium to turn on each light, it is possible to apply light energy of a wavelength corresponding to the image signal from among multiple types of light energy to the transfer recording medium, thereby making it possible to perform multicolor transfer recording. becomes.

In FIG. 5, S ₃ is a switch mechanism for causing the heating element 4 to generate heat in accordance with the image signal, E ₁ is a power source for causing the light emitting element to emit light, and E ₂ is a switch mechanism for causing the heating element 4 to emit light. It is a power source for generating heat.

Furthermore, in order to efficiently apply the light energy from the light emitter 5 to the transfer recording medium 9a as described above, aluminum metal powder with a diameter of several microns is placed inside the optical waveguide 7 on the upper surface of the heating element 4 as shown in FIG. By configuring the light diffusing material 7a used, the light energy guided onto the heating element 4 by the optical waveguide 7 is uniformly dispersed by the light diffusing material 7a, and the light energy is uniformly applied to the transfer recording medium. It is something that

Note that the light diffusing material 7a is not limited to the aluminum metal powder, but may also use tin powder, iron powder, heat-resistant resin powder, or the like.

Furthermore, the structure of the light diffusing material 7a does not have to be inside the optical waveguide 7, and the same effect can be obtained by configuring a light diffusing layer coated with a light diffusing material on the upper surface of the optical waveguide 7 located above the heating element 4. You can get the effect.

Furthermore, instead of providing the light diffusing material 7a, the optical waveguide 7 on the heating element 4 is provided with a minute protrusion whose tip is tapered with respect to the light emitting surface, or by roughening the light. A similar effect can be obtained by forming a scattering section.

<Effects of the Invention> As described above, the head according to the present invention is equipped with a heating element that applies thermal energy to the transfer recording medium, a light emitter that applies optical energy, and an optical waveguide. It is possible to apply heat energy to the transfer recording medium at the same time and from the same side. Therefore, a platen roller or the like can be placed on the opposite side of the recording head, so that the degree of adhesion between the head and the transfer recording medium can be improved. It is possible to improve the transfer performance, increase the transfer speed, and furthermore, if the light emitting body is composed of a plurality of light emitting bodies with different wavelengths, it is possible to perform multicolor transfer recording. It is something that you have.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a photothermal recording head according to an embodiment of the present invention, FIG. 2 is a cross-sectional view, FIG. 3 is an explanatory view of the recording configuration, and FIGS. It is an explanatory diagram. A is the head, 1 is the substrate, 2 is the glaze layer, 3,
6 is an electrode, 4 is a heating element, 5 is a light emitter, 5a is a red light emitter, 5b is a green light emitter, 7 is an optical waveguide, 7a
8 is a light diffusing material, 8 is a reflector, and 9 is an ink/donor film.

Claims (1)

Claims: 1. A photothermal recording head comprising a heating element, a light emitting element, and an optical waveguide for guiding light from the light emitting element onto or near the heating element. 2. The photothermal recording head according to claim 1, comprising a plurality of said light emitters each having a different wavelength. 3. A recording device comprising a photothermal recording head and a control circuit for controlling the photothermal recording head, wherein the photothermal recording head includes a heat generating element, a light emitting body, and directs the light of the light emitting body onto or on the heat generating body. 1. A recording device comprising, on a substrate, an optical waveguide that guides the optical waveguide to the vicinity thereof.