JPS60204381A - Transfer-type thermal printer - Google Patents

Abstract

PURPOSE:To perform thermal transfer recording without using ink ribbons, by a method wherein a heater is provided for melting a heat-fusible ink and supplying the melted ink to heating elements brought into contact with a recording paper, and a pulse equal to the logical sum of electric pulses supplied to the heating elements is impressed on the heater. CONSTITUTION:The heating element 5 is produced by, for example, bending a nichrome plate having a thickness of about 0.02mm. and providing a hole 5a having a diameter of about 0.03mm. at the center of the bent part. One end of each of the elements 5 is connected to a common electrode 5b, and the other is connected to a pulse generator 3. The heat-fusible ink supplying heater 6 is constituted of a pair of thin resistors opposed to each other with a small gap therebetween, one end thereof is connected to the heating elements 5, and the other is connected to an ink reservoir. A pulse signal to the logical sum of the electric pulses supplied to the heating elements 5 is impressed on the heater 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a heat-generating element by thermally melting solid thermal ink, guiding it to a heat-generating element using capillary action, and selectively energizing the heat-generating element to generate heat. The present invention relates to a transfer-type thermal printer that transfers thermal ink to a recording member such as paper that is brought into contact with or close to contact with a recording member.

[Prior art and problems]

2. Description of the Related Art Conventionally, there is a thermal transfer method as a printer that records by thermally melting thermal ink. However, this method uses disposable thermal ink film, so running costs are high, processing and storage of used thermal ink film takes up a lot of space, and the mechanism is complicated, which limits miniaturization and low price. There are disadvantages such as becoming.

As a way to modify this, we replaced the disposable heat-sensitive ink film with endless tape.

An ink reapplying type is being considered in which heat-sensitive ink is applied at a location away from the recording paper. This method requires a heater to melt the thermal ink, a device to apply the thermal ink uniformly, and rollers and endless tape to apply the thermal ink, making the machine complex and requiring both cost and space. Another thing is not enough.

[Purpose of the invention]

An object of the present invention is to provide a printer that uses solid thermal ink with a simple structure without using a thermal ink film or an ink reapplication mechanism.

[Structure of the invention]

That is, the present invention includes a thermal ink supply heater that heat-melts solid thermal ink and supplies it to a heating element using capillary phenomenon; and the heating element. The above object is achieved with a simple structure by causing the thermal ink supply heater to generate heat in synchronization with the heating of the heating element σ).

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the functions of each part of a transfer type thermal printer according to an embodiment of the present invention.

1 is an external image signal generator, 2 is an image signal processing device-3
is a pulse generator, 4 is a heater power supply, 5 is a heating element, 6
7 is a thermal ink supply heater, 7 is a thermal ink, and 8 is a printer head whose main parts are a heating element 5, a thermal ink supply heater 6, and a thermal ink 7. 9 is a recording member such as paper, and 10 is a recording member feeding mechanism.

FIG. 2 is a perspective view of a printer head portion of a transfer type thermal printer according to an embodiment of the present invention, showing only the main components for ease of understanding. 5 is a heating element, for example, by bending an electric resistor such as a nichrome plate with a thickness of Q, about 0.2 mm, and placing a diameter of 0.03 mm in the center of the bent part.
A hole 5a of the same size as that shown in FIG. One end of the heating element 5 is a common electrode 5b, and the other end has independent electrodes,
It is connected to the pulse generator 6. Hole 5a of heating element 5
The recording member 9, such as paper, is brought into contact or close to contact with the periphery of the recording member 9. Reference numeral 6 denotes a thermal ink supply heater, which is made of an electric resistor such as a nichrome plate having a thickness of about 0.02 mm, and has a narrow gap at its folded portion, in which the heating element 5 is sandwiched. In addition, there is a head difference 6a in a part. Ink No. 7 is a thermal ink whose main component is a binder material such as wax and colorants such as pigments and dyes dispersed therein.It is solid at room temperature and has a melting point of about 60 degrees Celsius.

FIG. 3 is a schematic cross-sectional view of the print head viewed from the direction of the lower right arrow in FIG. 2, and is numbered the same as in FIG. 1. However, 11 is a container containing the thermal ink 7, and 12 is a platen. Further, the shaded area is the area filled with thermal ink due to capillary action. In FIG. 4, 1 is the output waveform of the pulse generator 3, and 2 is the output waveform of the heater power source 4.

Next, I will explain the effect.

To explain the overall outline of the transfer type thermal printer of the present invention in FIG. send.

The pulse generator 3 generates electric pulses that selectively cause the heating element 5 to generate heat according to the image signal. Heater power supply 4 supplies power to thermal ink supply heater 6 to heat it. The thermal ink 7 is thermally melted by the thermal ink supply heater 6 and supplied to the heating element 5 by capillary action.

Since the heating elements 5 selectively and sequentially generate heat, the thermal ink 7 is transferred in accordance with the image onto the recording member 9 that is fed by the recording member feeding mechanism.

Next, details of the printer head section will be explained according to FIGS. 2 and 3. When the thermal ink supply heater 6 generates heat with electric power from the heater power source 1 4, the bottom of the thermal ink 7 melts. The thermal ink supply heater 6 has a folded part where the heaters face each other with a narrow gap, so the thermal ink 7 therein melts and becomes a highly viscous liquid and moves towards the heating element 5 by capillary action. . The heating elements 5 also face each other with a narrow gap, and the lower part is sandwiched by a part of the fold 1 of the thermal ink supply heater 6, so the thermal ink 7 supplied to the lower part of the heating element 5 is also heated by the heating element due to capillary phenomenon. The inside of the folded portion of the heating element 5 is always filled with the thermal ink 7. When an electric pulse corresponding to an image signal is applied to the heating element 5 in this state, the thermal ink 7 in that area is melted in the bath and transferred to the recording member 9 through the hole 5a of the heating element 5.

At this time, the heat-sensitive ink 7 expands in volume by about 17% when it changes from a solid state at 20'C to a molten state at 90'C, so it is pushed out from the hole 5a, so that the transfer to the recording member 9 is performed smoothly. Therefore, the recording member 9 does not necessarily completely cover the heating element 5.
It is not necessary to make contact with the tip of the material, but it may be in a state close to contact, which is advantageous in terms of wear.

When power is supplied to the ink supply heater 6, as shown in FIG. 4, when there are a plurality of heating elements 5, an electric pulse is added that is the logical sum of the electric pulses supplied to the heating elements 5. By doing this, the thermal ink can be supplied to the heating element 5 without any shortage, and the thermal ink in the portion of the heating element 7 which is not energized will not be melted. Further, a head 6a is provided at -↑91i of the thermal ink supply heater, thereby preventing excessive supply of the thermal ink 70 to the heating element 5 due to gravity, and making it possible to supply an appropriate amount only by capillary action. A recording member 9 such as paper is fed by a recording member feeding mechanism 10 . Further, a platen 12 is provided on the opposite side of the heating element 5 with respect to the recording member 9, and the positional relationship between the heating element 5 and the recording member 9 is maintained appropriately.

In this way, a desired image can be obtained as a collection of dots on the recording member 9 with a simple structure. In addition, unlike thermal ink films, there are no extra consumable parts, and only the thermal ink 7 necessary for recording one image needs to be supplied.
No matter what the shape is, it is a method that melts the bottom part, so there is no problem.

If color ink is used as the thermal ink 7, it is naturally possible to record a color image, and by using three different primary color inks in each of the three print heads, it is also possible to print a seven-color multi-color image. This is self-evident.

Furthermore, if the output of the image signal generator 1 includes a signal of light and dark density in units of dots, if the electrical energy of the electrical pulse output of the pulse generator B is changed accordingly, the heat-sensitive ink 7 is transferred from the heating element 5 to the recording member 9. The amount of transfer can be controlled. That is, for dark dots, the amount of transfer is increased by widening the pulse width of the electric pulse output from the pulse generator 6 or by increasing the pulse voltage, and vice versa for light dots. In this way, it is possible to print in full color with shading similar to a color photograph. Here, images naturally include characters, symbols, graphs, etc.

〔Effect of the invention〕

As described above, according to the present invention, only the thermal ink that is actually transferred to the recording member needs to be replenished, and the heating element and thermal ink supply heater can also be easily fabricated by etching a thin electrical resistor. It has a simple structure, low maintenance costs, and can provide clear color images.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the functions of each part of an embodiment of the present invention, Fig. 2 is a perspective view showing the configuration of only the main parts of the print head, Fig. 3 is a cross-sectional view of a model of the print head, and Fig. 4 is a block diagram showing the functions of each part of an embodiment of the present invention.
The figure is an output waveform diagram of the pulse generator and heater power source. 5... Heating element, 5a... Hole, 6...
...Thermal ink supply heater, 7...Thermal ink. Patent applicant Citizen Watch Co., Ltd.

Claims (2)

[Claims] (1) In a printer that uses solid thermal ink and selectively melts it with a heating element and transfers it to a recording member, the solid thermal ink is thermally melted and supplied to the heating element using capillary action. What is claimed is: 1. A transfer type thermal printer comprising: a thermal ink supply heater and the heat generating element; the heat sensitive one ink supply heater generates heat in synchronization with the heat generation of the heat generating element. (2) The heating element is in the shape of a bent thin plate, and is an electric resistor with a hole in the center of the bent part through which hot melting thermal ink passes, and the thermal ink supply heater holds the heating element between both sides. 2. The transfer type thermal printer according to claim 1, wherein the printer is an electric resistor having a shape of .