JPH01154773A - Electro-transfer recording device - Google Patents

Abstract

PURPOSE:To reduce the number of recording electrodes to be simultaneously electrically conducted, to stabilize an electric current, and to eliminate irregularities in density and size, by a method wherein, only a plurality of recording electrodes arranged in a line are brought into pressure contact with an ink ribbon, a control circuit conducts a time-sharing drive simultaneously driving the aforesaid recording electrodes at every N-pieces, and all the undriven recording electrodes are electrically grounded. CONSTITUTION:A control circuit 5 conducts a time-sharing drive of electrodes at every N-pieces. In the first example, the case with N=3 is described. When the control circuit 5 is actuated and thereby predetermined transistors 2 or 3 are turned ON, a recording current passes from recording electrodes 1 with the transistors 2 turned ON through a path shown by a broken line. As a result, a resistant layer 7 just under the recording electrodes generates Joule heat, whereby an ink layer is melted to be transferred to a recording paper. Usually, either of the transistors 2 or 3 connected to the recording electrodes 1 are turned ON. Because the recording electrodes with the transistors 2 ON is smaller in number than the recording electrodes with the transistors 3 ON, an electric current converges just under the former recording electrodes and thus the ink on the appropriate part is transferred.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrical transfer recording device used in a printer or the like that records image information, character information, etc. of electrical signals as a visible image.

BACKGROUND OF THE INVENTION In recent years, electronic computers, personal computers, and the like have become more sophisticated, and printers, which are terminal devices for these devices, are in high demand and require high performance. Various recording methods are known, but among them, electrical transfer recording is superior in print quality and recording speed.

The conventional electrical transfer recording apparatus described above will be described below with reference to the drawings.

A conventional electrical transfer recording device is, for example, disclosed in Japanese Patent Application Laid-open No. 60-78.
This is shown in Japanese Patent No. 766. FIG. 5 is a diagram showing the principle of the conventional electric transfer recording method. FIG. 6 is an end view of a print head used in a conventional electrical transfer recording apparatus. In FIG. 5, 6 is a recording sheet, resistors IJ7. ! ! ; Consists of two layers: thermal ink layer 8; 9 is paper. 1 is a plurality of recording electrodes, 13 is an insulating material that fixes the recording electrodes L, and a return electrode 12 is provided in parallel to this array of recording electrodes, from which a node is formed to the electrodes. . The recording electrodes 1 are each connected to a drive circuit 14, and are brought into contact with a resistor N7 of the recording sheet 6 to which a signal voltage is applied.

Further, a return electrode 12 is connected to the drive circuit 14 and is in contact with the resistance layer 7 of the recording sheet 6 . When a signal voltage is applied from the drive circuit 14 to the recording electrode 1, a current flows as shown by the arrow in the figure, increasing the resistance N between the recording electrode 1 and the return electrode 12.
7 generates heat, and the ink layer 8 further below is melted and transferred to the cover 9.

Problems to be Solved by the Invention However, the above configuration has a problem in that multi-dot printing causes uneven printing and the printing quality is poor for the following reasons. In other words, when an interaction occurs between the recording electrodes and a voltage is applied between each recording electrode and the return electrode, adjacent recording electrodes are affected by other electric fields and the path of current from the recording electrode to the return electrode is reduced. As a result, a phenomenon occurs in which the current flowing from the recording electrode to the return electrode becomes smaller. This phenomenon is shown in FIG. As described above, when the number of driven recording electrodes changes and the Th flow changes when the driven recording electrodes are adjacent to each other, the size of the recorded dots becomes uneven, resulting in uneven printing.

Another problem is that with the conventional print head shown in Figure 6, if the recording electrode and the return electrode are not kept in contact with the resistive layer, current will not flow between the two electrodes and a dot will occur. In order to bring both electrodes into stable contact with the ink ribbon, it is effective to increase the contact pressure with the ink ribbon, but with conventional print heads, the contact area becomes large. It was not possible to easily increase the contact pressure.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides an electrical transfer recording device that can stably print clean dots and perform high-quality printing.

Means for Solving the Problems In order to solve the above problems, the current transfer recording apparatus of the present invention presses only a plurality of recording electrodes arranged in a row against an ink ribbon, and selectively applies a signal voltage to the recording electrodes. The driving circuit that applies the voltage is time-divisionally driven to simultaneously drive every N recording electrodes, and a signal voltage is applied to the recording electrodes that are driven to form pixels, and all recording electrodes that are not driven are electrically grounded. It was configured to do so.

Operation The present invention operates as follows with the above-described configuration. Since a plurality of recording electrodes are arranged in a line and only the recording electrodes are brought into pressure contact with the resistance layer of the ink ribbon, contact pressure can be easily obtained and stable contact can be maintained. Furthermore, the drive circuit is configured to perform time-division driving in which every N recording electrodes are simultaneously driven, and all recording electrodes to which no signal voltage is applied are electrically grounded, so there is no need to provide a special return electrode. , the structure of the head becomes simpler, it becomes easier to process, and the structure of the device becomes simpler.

EXAMPLE Hereinafter, an electric transfer recording apparatus according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram showing an example of an energization drive circuit used in an energization transfer recording apparatus according to an embodiment of the present invention. 1st
In the figure, reference numeral 1 denotes a plurality of recording electrodes, which are in contact with the recording sheet 6. The recording sheet 6 has a resistive layer 7. Ink N8-2
Consists of layers. Each recording electrode l has a driving transistor 2.
and 3 are connected. The emitter sides of driving transistors 2 and 3 are connected to the recording electrode 1, the collector side of the driving transistor 2 is connected to a constant voltage source 4, and the collector side of the driving transistor 3 is electrically grounded. The base sides of the drive transistors 2 and 3 are connected to a control circuit 5, which controls ON and OFF of the drive transistors 2 and 3. Further, FIG. 2 is a timing chart showing the drive timing of the drive transistors 2 and 3. H indicates the drive timing of the drive transistor 2, and L indicates the drive timing of the drive transistor 3.Also, the drive circuit 5 performs time-division drive of every N transistors, but in this embodiment, the case where N=3 is If the control circuit 5 is operated to turn on a predetermined transistor 2 or 3, transistor 2 will turn on.
A recording current flows through the path shown by the broken line from the recording electrode 1 that has been set to the same position. As a result, the resistance layer 7 directly under the recording electrode generates heat due to Joule heat, and the ink layer is melted and transferred to the recording paper.

As shown in FIG. 2, only one of the transistors 2 and 3 connected to the recording electrode 1 is always turned on. As mentioned above, there are fewer recording electrodes with transistor 2 turned on than recording electrodes with transistor 3 turned on, so current concentrates directly under the recording electrode with transistor 2 turned on, and ink in that area is transferred. be.

In addition, in the current transfer recording device of the present invention, time-division driving is performed for every N electrodes, but if N = 0, all the recording electrodes will have the same potential and no current will flow, or if an attempt is made to print dots. There are more recording electrodes than electrically grounded recording electrodes, and a phenomenon occurs in which the current is not concentrated and no dots are printed. Even when N=1, the number of recording electrodes that are electrically grounded is the same as the number of recording electrodes on which dots are to be printed, and dots are also printed directly below the recording electrodes other than those on which dots are to be printed.

Therefore, if the value of N is N=2 or more, the number of recording electrodes that are electrically grounded is greater than the recording electrodes that are trying to print dots, and the number of recording electrodes that are electrically grounded is greater than the recording electrodes that are trying to print dots. The positional relationship of the recording electrodes is now appropriate. In other words, two or more recording electrodes that are electrically grounded are inserted between the recording electrodes on which dots are to be printed. Experiments have shown that when this number is small, uneven dot printing is likely to occur. However, N
If the value of is too large, the printing speed will be slow, so 2≦N≦
4 is desirable. FIG. 4 shows the current flow from the recording electrode of this example.

Furthermore, when a plurality of recording electrodes are arranged in a line, if an attempt is made to print dots using the recording electrodes at both ends, the flow of current will be restricted because there is no electrode on one side. Therefore, if the recording electrodes at both ends are always electrically grounded without printing dots, the dots at both ends will not be distorted. A substrate 11 showing a perspective view of
It is possible to use a head with a simple structure in which a conductive material is arranged as an electrode 10 on top of the head.

Furthermore, since sufficient contact pressure with the recording sheet can be obtained, stable contact can be maintained. Further, the material of this head is not particularly limited. In this example, the recording sheet had a 2N structure, but it has three layers: a resistive layer, a conductive layer, and an ink layer.
It may have a layered structure or a multilayered structure.

Effects of the Invention As described above, the energization transfer recording device of the present invention includes a control circuit that controls the energization of a plurality of recording electrodes, and this control circuit performs time-division driving in which the plurality of recording electrodes are simultaneously driven every Nth. Since all the recording electrodes that are activated and not driven are electrically grounded, it is possible to reduce the number of recording electrodes that are energized at the same time, stabilize the current, and eliminate unevenness in density and size. Furthermore, since a print head with recording electrodes arranged in a row is used, it is possible to easily obtain contact pressure with the sheet and maintain stable contact. Moreover, since the dots are printed directly below the electrodes, the transfer efficiency is also good. On the other hand, the structure of the head is simple and easy to process, and at the same time, the structure of the device can be made simple and compact.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of an energization drive circuit used in an energization transfer recording apparatus according to an embodiment of the present invention, FIG. 2 is a timing chart showing the drive timing of the drive transistor, and FIG. A perspective view of an example of print heads arranged in a row, FIG. 4 is a schematic diagram showing the flow of current from the recording electrodes of this embodiment, FIG. 5 is a principle diagram of the conventional current transfer recording method, and FIG. FIG. 7, which is an end view of a print head used in a conventional current transfer recording device, is a state diagram showing the flow of current from the recording electrodes in the conventional current transfer recording device. l... Recording electrode, 2.3... Drive transistor, 4... Constant voltage source, 5...
Control circuit, 6... Recording sheet, 7...
Resistive layer, 8... Ink layer, 9... Recording paper, 10... Conductive material, 11...
substrate. 1- Recording electrode 82 Figure Recording electrode/1/Q Figure 3

Claims (2)

[Claims] (1) A plurality of recording electrodes arranged in a line using an ink ribbon including at least a resistive layer and a heat-sensitive ink layer;
A moving means for relatively moving the recording electrode while being in pressure contact with the resistance layer, and a drive circuit for selectively applying a signal voltage to the recording electrode, the driving circuit for applying the signal voltage to the recording electrode to form a pixel. The driving circuit is characterized in that when applying the signal voltage, time-division driving is performed in which every N recording electrodes are simultaneously driven, and all the recording electrodes to which the signal voltage is not applied are electrically grounded. Electric transfer recording device. (2) The current transfer recording apparatus according to claim (1), wherein the drive circuit is configured so that the electrodes at both ends of the recording electrode array are always electrically grounded.