JPS6225065A - Thermal printer - Google Patents

Abstract

PURPOSE:To enable low price, low power consumption and high-speed printing with reductions in size and weight by forming a thermal transfer layer through a print head laminated at least with a transparent conductive layer and a font conductive layer on a substrate, and a conductive layer on a support having resistivity. CONSTITUTION:A print head 3 is formed of four layers laminated with a transparent substrate 31 of the lowermost layer, a transparent conductive film layer 32, a photoconductive layer 33 and a conductive layer 34 having wear resistance of 128-256mm X several mm-10cm of size. A print ribbon 4 is provided with a thermal transfer layer 44 through a conductive layer 43 on a support 42 having resistivity. The support 42 side is contacted on the layer 34, the layer 44 is press-bonded to a recording sheet 7, the prescribed voltage is applied between the layers 32 and 43, and a photoimage of the desired printing pattern is emitted from the substrate side. The layer 33 is reduced in the resistance, and the ink of the layer 44 is softened by heating and transferred on the sheet 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer suitable for use as an output device or copying device for personal computers, hand belt computers, word processors, etc.

[Background of the invention]

The following two types of prior art are related to the thermal printer of the present invention. One is an optical printer (including liquid crystal printers and LED printers), and the other is an electrical thermal transfer printer.

The former type of optical printer has the same problems as electrophotography, requiring processes from charging to fixing, and requires the use of a high-voltage power source.

In addition, the use of photoreceptor drums increased the size of the machine, and the photoreceptor drums were sometimes toxic. On the other hand, the latter uses a resistive ribbon and current-carrying electrodes to achieve good print quality even on paper with low smoothness, but the printing speed is slow because it uses a serial head to print while moving in the printing direction. Further, there was a problem in that mechanical precision was required and the movement of the head was complicated. Of course, even with a single current thermal transfer method, if you use a line-shaped head, you can make a high-speed, mechanically simple printer, but in this case.

Patterning of 1,000 to 2,000 electrodes is required, and the driving method is either matrix driving or driver I as used in line thermal heads.
This resulted in a direct drive drive using C, which had the problem of making the head section more expensive.

[Purpose of the invention]

This invention takes advantage of the advantages of the three printers mentioned above and solves the first problem.It is an object of the present invention to provide a thermal printer that is small and lightweight, is low in price, has low power consumption, is capable of high-speed printing, and has good print quality. It is an object.

[Structure of the invention]

In order to achieve the above object, the present invention comprises a print head formed by laminating at least a transparent conductive layer and a photoconductive layer on a substrate, and a thermal transfer layer provided on a resistive support via a conductive layer. It is equipped with a printing ribbon and an optical printing signal supply source, and is configured to print using optical input signals.

〔Example〕

Next, the present invention will be described based on embodiments shown in the accompanying drawings.

Fig. 1 shows the first embodiment, and in Fig. 2, ■ is the printer body, 2 is a platen, 3 is a print head provided opposite to the platen 2, and 4 is connected to a supply roller 4a and a take-up roller 4b at both ends. Winding.

A print ribbon is passed between the platen 2 and the printing nozzle, and 5 is a print signal supply source that supplies print signals to the print head 3 using light.

Reference numeral 6 designates a paper feed unit that supplies the recording paper 7 between the platen 2 and the print ribbon 4, 8 a paper discharge unit for the recording paper after printing, and 9 a control unit.

The print head 3 has a size of 128 to 2,561) m x several cranes to 1 Q cm, and has a transparent substrate 31. Transparent conductive film layer 32. Photocontact layer 33
and a wear-resistant conductive layer 34 are laminated to form a four-layer structure. Note that it is sufficient to provide this uppermost conductive layer [34] only when necessary. The photocontact layer 33 used here is, for example, +a-3i, Cds+Se,
GaAs, Ge.

Pb5e, PbS, PbTe, 5e-Te, 5e-Te
-As, OPC+CdTe, CdSe can be considered, and the film thickness is within the range of 500 to 10 μm, preferably 2.0 μm.
It is preferable to use the number within the range of 00 to 20,000 people. The wear-resistant conductive layer 34 is made of, for example, Mo, Ta+W,
AL, Ni, Go, Cr, Zn, Mn, N
b.

Metal materials such as Sn, Pb, Si, Fe, etc., or metal alloys made of a combination of these, and the thickness is 500 ~
The transparent substrate 31, which has a thickness of 10 μm, preferably 1 to 6 μm, is made of, for example, a transparent film such as TAC, PES, PET, or quartz, Corning 7059. Corning 7740. HOYA-NA40 plate glass is used, and its thickness can be from 100 μm to 101). The transparent conductive film layer 32 is made of indium oxide, tin oxide, or a mixed compound of the above oxides (hereinafter simply referred to as rl).
TO, J) thin film (for example, 100 to 3,000
person) is used.

Furthermore, the print head 3 may be of the type shown in the third figure. This structure consists of a three-layer body consisting of a bridge substrate 31' made of a metal with high conductivity and wear resistance starting from the lowest layer, a photocontact layer 33', and a transparent conductive film layer 32'. It can be used in the same manner as described above, only that the surface on which the light is incident is reversed from that shown in FIG. Note that it is desirable that the thickness of this electrode substrate 31' be as thin as possible (less than 5 mm) in order to prevent current diffusion.

The printing ribbon 4 is formed by providing a thermal transfer layer 44 on a resistive support 42 with a conductive layer 43 interposed therebetween, as shown in the fourth figure. The support has a resistance of about 10 μI, and polycarbonate can be used as the material. In addition, the conductive layer 4
3 is preferably A6, has a thickness of about 500 to 3,000 (preferably 1,000), and has a thermal transfer layer 44.
The amount should be several to several tens of microliters (preferably 61 Jm).

The printing ribbon 4 is then brought into contact with its support 42 side on the abrasion-resistant conductive layer 34 (or the contact layer 33 in the case of a three-layer structure) of the printing edge 3 as shown in the figure, and is then thermally transferred. At the same time, the layer 44 is pressed onto the recording paper 7, and the transparent conductive film layer 32 of the print head 3 and the conductive layer 43 of the print ribbon 4 are
By applying a predetermined voltage between and irradiating a light image of a desired print pattern from the substrate side of the print head 3, the photocontact layer 33 irradiated with light has a low resistance.
A current flows through the resistive layer of the ribbon support 42 and generates heat, softening the ink constituting the thermal transfer layer 44 and transferring it to the recording paper 7. The current applied to the printing ribbon 4 during this printing differs depending on what kind of ribbon is used, but in the case of the above example, a current of 20 to
50mA current (current density 200-500A/cn
! ) allows printing.

The printing signal supply source 5 is shown as consisting of a liquid crystal shutter and a light source in the example shown in the first figure, but it is also possible to use an optical system consisting of a laser and polygons similar to those used in laser printers or an LED array. It is possible.

■Specific example: An ITO film was formed by sputtering on a quartz substrate with a thickness of 3 mm, and a-5T was used as the photoconductive layer (photocontact layer 33), and a 5,000 layer was grown. A print head is used in which a film is formed by electrical discharge and a thin layer of graphite powder is applied on top of the film. This photoconductive layer has a power of 5+sW in a printing system using laser light.
When irradiated with laser light, the photoconductivity has a specific resistance of 102Ω and a dark resistance of 106Ω.

The spot diameter of the laser beam was set to 60 to 70 μm, and the current density per printing spot was set to 40 mA/(1
)00cr )” to energize the ribbon and its passing time 1
~2IIls.

When printed in this manner, even on transfer paper with low smoothness (Beck smoothness of 10 seconds or less), a print or image with high density was obtained without any deviation.

FIG. 5 shows a second embodiment, in which the print signal supply source 5 uses an optical system 50 that provides the same input signal as that of the copying machine to directly read an image and use it as a signal. The case is basically the same as the first embodiment, and the same parts are indicated by the same symbols, but since it is necessary to prevent the part where the light is irradiated to the printing/gutter 3 from being printed, the printing As shown in FIG. 6, the hem 3 has a transparent substrate 31. Transparent conductive film layer 32. The photocontact layer 33 and the abrasion-resistant conductive layer 34 are laminated to form a four-layer structure, which electrically connects the transparent conductive layer 32 and the conductive layer 43 of the printing ribbon 4, Between the wear-resistant conductive layer 34 and the transparent conductive MfA layer 32 and the wear-resistant conductive layer 3
4 and the conductive layer 43 of the printing ribbon 4. Therefore, in this case, the print head 3 requires a wear-resistant conductive layer 34.

〔Effect of the invention〕

As described above, the thermal printer according to the present invention is a print head formed by laminating at least a transparent conductive layer and a photoconductive layer on a substrate.

This is because it is characterized by comprising a printing ribbon formed by providing a thermal transfer layer on a resistive support via a conductive layer, and an optical printing signal supply source.

By providing a photoconductive layer on the head without using electrode patterning, it is possible to print using optical input signals, making it small and lightweight, making it possible to achieve low cost, low power consumption, high-speed printing, and good printing quality. This has an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the first embodiment, and FIG. 2 is an enlarged sectional view showing one configuration of the print head. FIG. 3 is an enlarged cross-sectional view showing another configuration of the print head, FIG. 4 is an enlarged cross-sectional view showing the configuration of the print head and print ribbon when a print signal is input, and FIG. 5 is an abbreviation of the second embodiment. A schematic cross-sectional view, FIG. 6, is an enlarged cross-sectional view of the print head and print ribbon used therein. 3-Print head 31-Transparent substrate 31'--Electrode substrate 32.32'-1-Transparent conductive film layer 33.33'--Photocontact layer 34-Abrasion-resistant conductive layer 4-Print ribbon 41 --- Resistive layer 42 --- Support 43 --- Conductive layer 44 --- Thermal transfer layer (ink) 5 --- Print signal supply source patent Applicant Konishiroku Photo Industry Co., Ltd. Figure 1 Figure 2 Figure 9 Figure 3 ↓

Claims (3)

[Claims] (1) A print head formed by laminating at least a transparent conductive layer and a photoconductive layer on a substrate, a print ribbon formed by providing a thermal transfer layer on a resistive support via a conductive layer, and an optical print signal. A thermal printer characterized by comprising a supply source. (2) The thermal printer according to claim 1, wherein the substrate of the print head is made of a transparent material. (3) The thermal printer according to claim 1, wherein the substrate of the print head is made of a highly conductive and wear-resistant metal.