JPH04255392A - Light-heat conversion type recording method and device - Google Patents

Abstract

PURPOSE:To reproduce a hot-melt ink layer by successively laminating a transparent conductive layer, a photoconductive layer, a conductive layer and a hot melt ink layer onto a base material on a light-transmitting hollow cylinder, applying voltage between the transparent conductive layer and the conductive layer and applying image information light from the inside. CONSTITUTION:A heat-generating drum 7 is composed by successively laminating a transparent conductive layer 2, a photoconductive layer 3, a conductive layer 4 and a hot-melt ink layer 5 on a light-transmitting hollow cylindrical substrate 1, and turned in the same direction as the carrying direction of recording paper by applying voltage between the conducitve layers 2, 4 from a power supply 6. When image information light is applied from the inside of the heat-generating drum 7, the resistance value of the photoconductive layer 3 is lowered to generate Joule heat, and the hot melt ink layer 5 is transferred and recorded on recording paper. When light irradiation is stopped, the photoconductive layer 3 recovers insulating properties thereof, the hot melt ink layer 5 is brought into contact with a heating roll by the revolution of the heat-generating drum 7, and a transferring section is supplied with ink and regenerated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermal conversion type recording method and recording apparatus in which light is converted into heat for recording.

0002

[Prior Art] Conventionally, as a thermal recording method, there are methods in which recording is performed using a thermal head as a heating element and a thermosensitive color recording material, a thermosensitive melt transfer recording material, a thermosensitive sublimation transfer recording material, and these methods are generally widely used. There is.

[0003] Thermosensitive color recording uses, as a recording paper, thermosensitive color paper in which a coloring layer in which fine particles of leuco dye and color developer are dispersed in a binder is provided on a base material such as cellulose fiber paper or synthetic paper. A piece of thermosensitive coloring paper is held between a thermal head and a platen roller so that the surface of the coloring layer is in contact with the thermal head, and the heat generated by the thermal head causes the coloring paper to develop color for recording. Recording is performed continuously by transporting thermosensitive color paper. Heat-sensitive melt transfer recording uses a heat-sensitive transfer film with a coloring material layer mainly made of pigment and wax on one side of a base material such as polyester film, and recording paper such as cellulose fiber paper, synthetic paper, or plastic film. A thermal head and a platen roller press the color material layer of the heat-sensitive transfer film and the recording paper, and the heat generated by the thermal head melts the color material layer of the heat-sensitive transfer film and transfers it to the recording paper. , recording is performed continuously by transporting the thermal transfer film and the recording paper. Heat-sensitive sublimation transfer recording uses a heat-sensitive transfer film with a dye layer consisting of a sublimable dye and a binder on one side of a base material such as a polyester film, cellulose fiber paper, synthetic paper,
Alternatively, an image receiving paper with a receiving layer provided on a base material such as a plastic film is used, and the dye layer of the thermal transfer film and the receiving layer of the image receiving paper are pressed together by a thermal head and a platen roller so that they are in contact with each other, and the thermal head generates heat. The dye layer of the heat-sensitive transfer film is sublimated and transferred to the image-receiving paper, and recording is performed continuously by conveying the heat-sensitive transfer film and the image-receiving paper.

[0004] Another method is to form conductive layers on both sides of a flat photoconductive layer and expose it to light while applying a voltage between the two conductive layers so that a current flows through the photoconductive layer in the light irradiated area and generates heat. A flat photothermal conversion type thermal recording device has also been proposed, in which a thermal recording paper is pressed into contact with the thermal recording paper (Japanese Unexamined Patent Publication Nos. 64-47561, 1983-118).
Publication No. 49).

[0005]

However, there are the following problems in thermal recording using a thermal head and a thermal recording material and in flat photothermal conversion type thermal recording.

■Thermal coloring paper and thermal transfer film are conveyed while being pressed between the thermal head and the platen roller. The thermomechanical load received is large.

[0007] For this reason, during printing, wrinkles occur in the thermal coloring paper and thermal transfer film, and residue scraped from the thermal coloring paper and thermal transfer film adheres to the thermal head, resulting in deterioration of print quality. .

(2) When the recording speed is increased, heat is accumulated in the thermal head and the recording density changes, so there is a limit to how much recording time can be shortened, and it is difficult to increase the recording speed.

(2) Since the number of recording pixels and resolution are determined by the number and density of heating elements of the thermal head, the same thermal head cannot perform recording with different numbers of recording pixels and resolutions.

[0010] In a flat photothermal conversion type thermal recording device, when the recording area is increased, it is difficult to uniformly contact the conductive layer of the flat recording device and the thermal recording material, resulting in uneven printing. This results in a decrease in print quality,
Furthermore, the mechanism for ensuring uniform contact between the conductive layer and the recording paper and the paper feeding mechanism become complicated, resulting in an increase in the size of the apparatus.

[0011] Since the thermal transfer sheet is used as a consumable item, the running cost is high, and the thermal transfer sheet is transported together with the recording paper, and the sheet whose used portion has been used at least once will not be used again.
The effective utilization rate of hot-melt ink is low.

[0012] The present invention is aimed at solving the above problems.
The number of pixels and resolution can be freely set without causing wear or heat accumulation on the recording head, and the contact between the recording head and recording paper can be easily made uniform, simplifying the device and eliminating the need for thermal transfer sheets. It is an object of the present invention to provide a photothermal conversion recording method and apparatus that reduce running costs and improve the effective utilization rate of ink.

[0013]

[Means for Solving the Problems] The present invention provides at least a transparent conductive layer, a photoconductive layer, a conductive layer, and a heat-melting ink layer, which are laminated in this order on a light-transmitting hollow cylindrical substrate. A rotatable heating drum with a voltage applied between the conductive layers is used as a recording element, and light is irradiated from inside the hollow cylinder according to the information of the image to be recorded, making the photoconductive layer conductive to generate Joule heat. The recording material is brought into pressure contact with the heat generating drum, and is conveyed in accordance with the rotational speed of the heat generating drum for recording.

[0014]

[Function] The present invention consists of laminating a transparent conductive layer, a photoconductive layer, a conductive layer, and a heat-melting ink layer on a light-transmitting hollow cylindrical base material, applying a voltage between the transparent conductive layer and the conductive layer, and making it rotatable. Image information light is irradiated from inside the heating drum, the photoconductive layer in the light irradiated area becomes conductive, causing Joule heat generation, and the heat-melting ink layer is transferred and recorded onto the recording paper, and the ink is further transferred. Since the heat-melt ink layer is regenerated by supplying ink to the area, the heat-melt ink layer is regenerated without using a heat transfer sheet, and the effective utilization rate of the heat-melt ink is improved. Continuous recording can be performed without interruption.

[0015]

Embodiment FIGS. 1 and 2 are diagrams for explaining the thermal recording principle of the present invention. In the figure, 1 is a light-transmitting hollow cylindrical substrate, 2 is a transparent conductive layer, 3 is a photoconductive layer, 4 is a conductive layer, 5 is a hot-melt ink layer, 6 is a power source, 7 is a heating drum, and 8 is powder 9 is a heat roll, 10 is a platen roll, and 11 is a recording paper.

As shown in FIG. 1, the heating drum 7 is constructed by sequentially laminating a transparent conductive layer 2, a photoconductive layer 3, a conductive layer 4, and a heat-melting ink layer 5 on a light-transmissive hollow cylindrical substrate 1. ,
A voltage is applied between the transparent conductive layer 2 and the conductive layer 4 by a power source 6, and the layer can rotate in the circumferential direction of the cylindrical surface, and during recording, recording is performed while rotating in the same direction as the conveyance direction of the recording paper. It is something. A light-transmissive hollow cylindrical substrate 1 supports a transparent conductive layer 2, a photoconductive layer 3, a conductive layer 4, and a heat-melting ink layer 5, and transmits light irradiated from inside the heating drum by an exposure means (not shown). It has the function of causing the photoconductive layer to reach the photoconductive layer 3. The transparent conductive layer 2 transmits light from the exposure means and is connected to a power source 6 to apply a voltage between it and the conductive layer 4, and may be made of, for example, an indium/tin oxide thin film.

The photoconductive layer 3 is made of a material such as selenium, amorphous silicon, etc. whose electrical resistance decreases when exposed to light, and other materials such as CdS, CdSe, HgCdTe, and Pb.
SnTe, etc., or Ge, Si, Au, Hg, Cu, Z
A material doped with n or the like may be used, and in addition to this, a wide variety of conventionally known photoconductive materials used for electrophotographic photoreceptors, photodiodes, and phototransistors can be used.

The conductive layer 4 is used to apply a voltage between it and the transparent conductive layer 2, and also has the role of transmitting Joule heat generated in the light-exposed portion of the photoconductive layer 3 to the heat-fusible ink layer 5. A wide variety of conventionally known good conductors such as iron, copper, nickel, chromium, aluminum, cobalt, magnesium, carbon, silicon, or alloys thereof can be used. Note that since the conductive layer 4 needs to efficiently transmit the heat generated in the photoconductive layer to the heat-fusible ink layer 5, it is preferable to have a thickness of about several μm in order to reduce the heat capacity. Further, a resistance layer may be provided between the transparent conductive layer 2 and the photoconductive layer 3 and/or between the photoconductive layer 3 and the conductive layer 4 as necessary to generate heat.

When the heating drum 7 having such a structure is irradiated with light from an exposure means (not shown), the resistance of the photoconductive layer in the irradiated area decreases, and the transparent conductive layer provided to sandwich the photoconductive layer 3 decreases. Since the layer 2 and the conductive layer are connected to the power supply 6 and a voltage is applied thereto, when the resistance value of the photoconductive layer 3 decreases, a current flows in the thickness direction and Joule heat is generated. Next, when the light irradiation is stopped, the photoconductive layer 3 becomes insulating,
Current will no longer flow and Joule heat generation will no longer occur. In other words, the same operation as a thermal head can be performed. This Joule heat generation melts the ink in the thermofusible ink layer 5, and when the recording material is brought into pressure contact with the thermofusible ink layer 5, the ink is transferred to the recording material. By transporting the photoconductive layer 3 and controlling the light irradiation to the photoconductive layer 3 in accordance with the image information, it is possible to perform arbitrary image recording.

The exposure means used in the present invention is a combination of a laser light source such as a semiconductor laser, an Ar laser, or a He-Ne laser, a modulation means, and a scanning means, or an LE
D. One-dimensional or two-dimensional light-emitting elements such as plasma light-emitting cells
A combination of an exposure head arranged in two dimensions, a liquid crystal array in which liquid crystal cells with a shutter function are arranged in one or two dimensions, and a light source, a negative original, a light source, and transmitted or reflected light from the negative original on a conductive layer. A combination with an optical system that forms an image can be used, but the invention is not particularly limited to these.

As shown in FIG. 2, thermosensitive recording is carried out by pressing the recording paper 11 against the heating drum 7 by means of a platen roll 10, and by irradiating the pressed portion with light to expose the image, the thermally fusible material is produced as described above. The ink layer 5 is melted, the ink is transferred to the recording paper 11, and recording is performed. When the heating drum in the area where printing is performed passes the powder ink supply section 8, a bias voltage is applied between the heating drum 7 and the powder ink supply section 8, and the powder ink is heated and melted as an image. The ink layer is supplied to the ink layer. Subsequently, the heating drum passes through a pressure contact portion with a heat roll 9 heated to a predetermined temperature, and the heat-fusible ink is bonded with heat and pressure, and the surface is leveled. The heat-generating drum in the area where the heat-fusible ink layer has been regenerated in this manner moves on to the next printing process, and thermal recording is sequentially performed.

FIG. 3 is a diagram showing an example of supplying ink to a heating drum using ink having supercooling properties, in which the ink having supercooling properties is solidified on the ink roll 12 to form a supercooling ink layer 13. The ink is melted by heating by the ink heating means 14, and the supercooled ink is melted and transferred to the heating drum, thereby replenishing the ink consumed by printing.

FIG. 4 is a diagram showing an example in which ink is supplied using charged toner, in which a mixture of a binder resin having a melting point of about 50 to 80° C., and a pigment and/or dye is contained in the toner tank 18. Powdered colorant coated with magnetic powder (
Toner) is charged and supplied from the toner tank 18 to the heat generating drum 7 using a magnetic roll 16.The heat generating drum 7 is charged with toner in advance using a charging means 15 such as a corona discharger or a charging brush. The toner is transferred to the heat generating drum by charging it with different polarities or by applying a voltage between the magnet roll and the heat generating drum as necessary. By doing so, it is possible to replenish ink to the area where ink has been consumed due to printing. Further, a fixing means may be provided between the ink replenishing means and the printing section to melt the toner transferred onto the heating drum and form a uniform ink layer.

[0024]

As described above, according to the present invention, the number of pixels and resolution can be freely set without abrasion or heat accumulation of the recording head, and the contact between the recording head and the recording paper can be easily made uniform. Not only can the apparatus be simplified, but also continuous recording can be performed without using a thermal transfer sheet and without causing heat accumulation or consumption of the recording head while effectively utilizing heat-melting ink.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the thermal recording principle of the present invention.

FIG. 2 is a diagram for explaining the thermal recording device of the present invention.

FIG. 3 is a diagram showing an example of supplying ink to a heat generating drum using ink having supercooling characteristics.

FIG. 4 is a diagram showing an example in which ink is supplied using charged toner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Light-transmitting hollow cylindrical substrate, 3... Photoconductive layer, 4... Conductive layer, 5... Heat-melting ink layer, 6... Power source, 7... Heat generating drum, 8... Powder ink supply section, 9... Heat roll , 10... platen roll, 11... recording paper.

Claims (4)

[Claims] 1. At least a transparent conductive layer, a photoconductive layer, and a conductive layer are laminated in this order on a light-transmissive hollow cylindrical substrate,
Light is irradiated from inside the hollow cylindrical rotatable heat-generating drum in which a voltage is applied between the transparent conductive layer and the conductive layer in accordance with the information of the image to be recorded, and the photoconductive layer is made conductive to generate Joule heat generation. This is a photothermal conversion recording method in which the recording material is brought into pressure contact with a heat-generating drum and is conveyed at the rotational speed of the heat-generating drum for recording. A photothermal conversion recording method characterized by transferring heat from a heat generating drum to recording paper and recording. 2. The method according to claim 1, wherein ink is supplied to a portion of the heat-fusible ink layer to which the ink has been transferred to regenerate the heat-fusible ink layer, thereby repeatedly performing printing and recording operations. photothermal conversion recording method. 3. At least a transparent conductive layer, a photoconductive layer, and a conductive layer are laminated in this order on a light-transmissive hollow cylindrical substrate,
Light is irradiated from inside the hollow cylindrical rotatable heat-generating drum in which a voltage is applied between the transparent conductive layer and the conductive layer in accordance with the information of the image to be recorded, and the photoconductive layer is made conductive to generate Joule heat generation. This is a photothermal conversion type recording device in which a recording material is brought into pressure contact with a heat-generating drum and is conveyed at the rotational speed of the heat-generating drum for recording. 1. A photothermal conversion type recording device, characterized in that ink in a thermofusible ink layer is transferred to recording paper by heat generation from a heat generating drum to perform recording. 4. The photothermal conversion type recording apparatus according to claim 3, further comprising means for supplying ink to a portion of the heat-fusible ink layer to which the ink has been transferred to regenerate the heat-fusible ink layer. .