JPS6146666A - Multi-stylus thermal sensing recorder - Google Patents

Abstract

PURPOSE:To simplify a driving circuit without high speed recording performance and to obtain an excellent picture by providing plural block electrodes corresponding respectively to plural stylus electrodes to form plural electrode sets thereby constituting a recording head. CONSTITUTION:The recording is started while one line's share of picture signals are fed to a shift register SR1 at first. As the 1st stage, a shift register SR3 designates a common stylus electrode xr1 via a driver circuit DR3 and a recording signal voltage corresponding to a picture element to be recorded at each position of stylus electrodes x11-xn1 is applied to block electrodes A1-An from a latch R1 via a driver circuit DR1 in parallel in this state. Then one output of the shift register SR3 is shifted to designate a common address yr1, and similarly a recording signal voltage at each position of stylus electrodes y11-yn1 is fed simultaneously to block electrodes B1-Bn via a driver circuit DR2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a multi-stylus thermal recording device suitable for high-speed recording.

[Technical background of the invention and its problems] In recent years, with the remarkable progress of information-related industries such as computers and facsimiles, various recording devices for recording characters, figures, etc. on recording paper have been put into practical use.

By the way, a stylus electrode and a block-shaped electrode are brought into contact with a recording material having a conductive support layer and a conductive heat-sensitive recording layer, and a signal voltage is applied between both electrodes. There is a current-carrying recording method in which recording is performed using an electric current, and FIG. 7 shows a known recording method in Proceedings 13 of the 4th National Conference of the Institute of Image Electronics Engineers in 1976.

In the figure, one surface of the base material 21 has an aluminum vapor deposited layer 22.
and the surface recording layer 23 are formed in a laminated manner to constitute a recording medium. The surface recording layer 23 has electrical conductivity and has the property of developing color when heated. When a recording signal voltage is applied between the block-shaped electrode 24 that contacts the surface recording layer 23 over a large area and the recording button 25 that contacts the surface recording layer 23 over a small area, the current is applied to the aluminum vapor layer, which has a lower resistance. It flows through the layer 22, but directly under the electrode it flows through the surface recording layer 23 in the thickness direction. In this case, a large amount of Joule heat is generated because the current is concentrated directly under the recording needle 25, which has a small cross-sectional area, and this Joule heat is designed to prevent the surface recording layer from developing color.

On the other hand, a recording method using a combination of a thermal transfer type ink sheet and a stylus electrode is also known;
It is a diagram showing the method described in the 17th Proceedings of the 12th National Conference of the Japan Society of Image Electronics Engineers, 1999.

In the figure, an ink sheet 26 is formed by providing a conductive ink layer 28 as a conductive heat-sensitive layer on a conductive base layer 27 as a conductive support layer.

When recording on the recording paper 29 using the thermal ink sheets 1 to 26, the conductive ink layer 28 side, which is the front surface of the ink sheet 26, is in close contact with the recording paper 29, while the back surface (back surface) of the ink sheet 26 is in close contact with the recording paper 29. By bringing the block-shaped electrode 30 and the stylus electrode 31 into contact with the conductive base layer 27 and applying a signal voltage from, for example, a recording signal source 32 between these electrodes 30 and 31, a current flows as shown by the arrow (stylus (when the electrode 31 side is positive), Joule heat is generated in the ink sheet 26 directly below the stylus electrode 31, and the conductive ink layer 28 is partially melted, causing the recording paper 2
9. Both electrodes 30 and 31 in this case are the ninth
The structure is as shown in the figure, and the stylus electrode 31
are arranged in a straight line in the center and the multi-stylus electrode 3
1.31. ....

31, and block-shaped electrodes 30, 30 are arranged on both sides thereof.

Conventionally, thermal recording methods have been put into practical use, in which a thermal recording head consisting of a large number of heating elements is brought into contact with a thermal recording sheet, but the thermal capacity of the heating elements is large; In addition, it is difficult to create a high-speed recording device because it takes time to transfer heat to the heat-sensitive sheet.
Expansion of recording dots due to heat diffusion, power supply capacity,
There were problems such as an increase in drive element capacitance. On the other hand, the system shown in FIG. 8 has a fast response speed because it utilizes internal heat generation for the heat-sensitive sheet 1, and has a small heat capacity, so the capacity of the power supply and drive circuit can be reduced. Also, there is an advantage that the increase in dot diameter due to heat diffusion can be suppressed, but the multi-stylus electrodes 31, 31. ...,
Since an independent drive circuit is connected to each of the 31 stylus electrodes 31, there is a problem that the drive circuit becomes complicated and large. Also, the stylus electrode 31 in FIG. . . , 31 at the same time, there is a problem in that interference occurs between adjacent electrodes and the recording density decreases.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and solves the problem of impairing high-speed recording performance in a thermal recording device configured to generate heat by applying electricity to a thermal recording sheet using multi-stylus electrodes. It is an object of the present invention to provide a multi-stylus thermal recording device configured so that the driving circuit can be simplified without any problems and a good image can be obtained.

[Summary of the Invention] The present invention comprises linearly arranged multi-squirrel electrodes;
A plurality of block-shaped electrodes are provided close to these, one corresponding to each of the plurality of stylus electrodes, to form a plurality of electrode sets, and further, non-adjacent electrode sets are grouped together to form an electrode set group. The present invention is designed to constitute a recording head, and to perform high-speed thermal recording with a simple configuration including a driving means for this recording head.

[Embodiments of the invention] Hereinafter, the present invention will be specifically explained with reference to the drawings.

Figures 1 to 3 relate to the first embodiment of the present invention.
The figure shows the first embodiment, FIG. 2 shows a recording head having multi-stylus electrodes in the first embodiment, and FIG. 3 is for explaining how recording is performed by the first embodiment. .

As shown in FIG. 2, the recording head 2 used in the thermal recording apparatus 1 of the first embodiment shown in FIG. 1 has a large number of stylus electrodes χ11. χ12
．． ”', χ+s, yn, −, yl5.

χ21, ..., χ25. V2+, ・・
・, y25. ..., χ η l .

..., χηs, Vη1. ..., yn5 are formed of multi-stylus electrodes arranged in an array. These multi-stylus electrodes χ1. Vt,..., χη, yη (here, χr and yl- are χl-1,..., yl5 and Vz
, ..., yrs is simply expressed. r is a natural number between 1 and n. ) adjacent to one side of the elongated block-shaped electrode A1. B1. A2, B2,...

Aη and Bη are arranged in a straight line with a minute interval between them.

In other words, block-shaped electrodes A+ arranged at predetermined intervals
, A2 , . . . , Aη, the other book-shaped electrode B1 . B2...

Bη are arranged.

Therefore, each of the stylus electrodes χ1. V1゜...,
χη, yη are adjacent block-shaped electrodes A1°Bt,...
・, Aη, Bη, multiple (5 each in Figure 2)
stylus electrode group (χ1), (V
t ), ..., (χη), (yn). That is, the stylus electrode group (χr), that is, χ'1.
..., yl5 is provided close to the block-shaped electrode Ar, while the stylus electrode group (Vrl is provided close to the block-shaped electrode Br)
is located close to.

Each of the block-shaped electrodes Ar (or Bl-) and the stylus electrode group (χi) (or (yl-)) belonging to (corresponding to) the block-shaped electrode Ar (or Br), each electrode group (
Ar, χr), (or (Br, Vr)) is formed. Therefore, the recording head 2 has one electrode group (A1.
), (A2゜χ2)..., (Aη, χη) ((A, χ
) and the other electrode set group (B+o, '11), (
B2, y2)..., (Bη, yn) (CB, y
It is composed of two groups of electrode sets (represented by l).

The configuration of the signal processing block of the recording head 2 consisting of the electrode group groups (A, χ) and (B, V) is shown in FIG.

That is, the time-series recording signal S1 is transferred to the shift register SR1.
from the shift register SRI to a plurality of stylus electrodes χIP spaced apart from each other by a predetermined distance in accordance with the configuration and wiring of the recording head 2.

χ2P,..., χηP:'1/IP,'/2ρ,°,
ynp (1) is a natural number from 1 to 5) to output a signal corresponding to (in the order p = 1.2..., 5, items with the same p are sequentially at the same timing) It is. In this case, one stylus electrode, χIP, χ2P, ..., χηP, is used for recording at the same timing.
A signal corresponding to is taken into the latch circuit R1. Similarly, signals corresponding to the other stylus electrodes y1p, y2ρ, . . . , yTIP for recording at the same timing are taken into the latch circuit R2.

Data output terminals of the latch circuits R1, R2 are connected to driver circuits DR1, DR2, respectively, and each driver circuit DP1. DR2 are block-shaped electrodes A1.・・・
., Aη and B1. ..., are connected to Bη. That is, the latch circuit R1 and the driver circuit DR1 are connected to one block-shaped electrode group A1. ....

It is connected to Aη.

Similarly, the other latch circuit R2 and driver circuit R2 are connected to the other block-shaped electrode group B+, . . . , Bη. Therefore, each block-shaped electrode At,
..., Aη;B1. ..., Bη has each driver circuit D
Recording signal voltages are applied simultaneously from R1 and DR2.

By the way, for each block-shaped electrode Δr (or Br),
A plurality of (5) stylus electrodes χri,"',
Since χrs (or Vz, -, Vrs) are made to correspond, these can be specified at different timings.

That is, 5×2 output terminals of the shift register SR3 to which the single pulse signal S2 is applied, that is, a number equal to the product of the number of stylus electrodes 5 making up each stylus electrode group and the number 2 of the electrode group groups. The output end of each is connected to a common stylus electrode (χl-1) (yz
), (χr2).

(Vr2), . . . , (χrη), (yrη). Here, for example, (χ2) is the stylus electrode χ
11. χ21. ..., χη1, and these stylus electrodes χ11 . χ21.・°°, χη1 are connected to the common stylus terminal TX1 of the driver circuit DR3 by making them conductive through a direct wire or the like. (Same for other (yl-1) etc.)
. By applying the single pulse signal s2, the shift register SR3 is controlled by a clock pulse (not shown).
The common stylus electrode to which a predetermined voltage is applied via the driver circuit DR3 is
1).

(Vz), (χr2), . . . , (yis) are sequentially transferred. From the above (χ2) (Vrη)
When one line in the row direction is recorded by applying a predetermined voltage for one cycle, scanning is performed in a direction perpendicular to that line, and the same recording is performed again.

The operation of the first embodiment configured as described above will be explained below with reference to FIG.

First, recording starts with one line of image signals sent to the shift register SR1.

As a first step (step 1), the shift register SR3 specifies the common stylus electrode (χ2) via the driver circuit DR3. On the other hand, in this state, the block-shaped electrode A1. A2...

Aη has each stylus electrode χ11. χ21. χ31.・
....

At each position of χη1, the recording signal voltage corresponding to the next pixel to be recorded is transferred from the latch circuit R1 (which held the signal output of the shift register SR1) to the driver circuit D.
are applied in parallel via R1. Therefore, the stylus electrode χ11. χ21. ....

The ink portion directly below χη1 is melted by Joule heat, transferred to recording paper, and recorded. For example, recording is performed as shown in FIG. 3(a). In the figure, the portion filled in black indicates the state in which recording has been performed.

When the recording in the above step 1 is performed, in step 2, the output of the shift register SR3 is shifted by one by the next clock pulse, and the common address electrode (V, rt
) is specified. In this timing state, the stylus electrode VI1. held by the latch circuit R2. V21.・
..., yη1, the recording signal voltage at each position is transmitted to the block-shaped electrode B1 . B2...
. and Bη simultaneously. In addition, shift register SR
The signal is transferred from latch circuit R1 to latch circuit R2.
It may be processed at the same time as the signal is transferred to 1, or it may be processed separately. By the above step 2, the stylus electrode VI1. V2+, ..., yη1 and block-shaped electrode B1
．． A high potential difference is applied between B2, . . . , Bη, and recording is performed as shown in FIG. 3(b).

When step 2 is completed, the next step is to apply a clock pulse to the shift register SR3 to designate the stylus electrode (χr2) and record as shown in FIG. 3(C). Next to this is the stylus electrode (Vr
2) is specified and recorded as shown in FIG. 3(d). In this way, the other stylus electrode (χr3), (
Vrs), .

In the first embodiment, in which electricity is applied during recording to directly heat the conductive heat-sensitive recording sheet, the time required to record one pixel is on the order of 10 [JIs]. Therefore, as in the first embodiment described above, the electrode group groups (A, χ), (B
, V) are each composed of 60 block-shaped electrodes (n=60), and the number of styli in the stylus group belonging to one block-shaped electrode Ar (or Br) is, for example, 17 (instead of 5). For example, the time required to scan an A4 size screen is 10 dots/ml! When recording at a dot density of 1], it takes 1 second. Electrode set group (A, χ1. (B.

The number of block-shaped electrodes constituting y) is 15 (n=
15), the number of styli in each stylus electrode group is 70, and in the case of the above dot density, one screen of A4 size can be recorded in 4 seconds. This speed is much higher than conventional devices using resistive heating heads.

According to the first embodiment, recording is performed simultaneously using a plurality of stylus electrodes, but since the stylus electrodes to which signals are simultaneously applied are sufficiently far apart from each other, mutual interference occurs. It is possible to stably record good images and the like at high speed without any problems.

FIG. 4 shows a recording head 12 in a second embodiment of the invention.

This recording head 12 has stylus electrodes χ1. y1.
χ2, V2, ・”, χn, yTl (here, yr represents χri, ..., yr5 as mentioned above)
On each side on both sides of the block-shaped electrodes Δ1, A2 .・
..., ATL:B1. B2. ..., Bη are arranged. In other words, one block-shaped electrode Δ1°A2. ...
, Aη are arranged on each stylus electrode group (χ1), (χ2), (χ3) so that they do not interfere with each other (there may be some variation).

. . . are formed in a straight line on one side close to (χη), and similarly block-shaped electrodes B+, B2, . . .
.

Bη also represents each stylus electrode group (Vl), (V2).

. . . are formed linearly on the other side close to (yη).

According to the recording head 12 in this second embodiment, the stylus electrodes χ1. 'Vt, χ2. Block-shaped electrodes A1°B1. A2,
Although it is difficult to accurately form B2, .
As long as it is formed close to the side of (Vr).), there is no problem even if there are considerable variations in the longitudinal direction.

In addition, each block-shaped electrode Ar (or Br) is connected to a stylus electrode group (yr) (or (yr )) belonging to the electrode.
Since it is formed for a longer time, the state when energized is
The recording head 2 in the first embodiment has two electrodes near the center and one near the end of the stylus electrode group (yr).
Therefore, the unevenness of the current distribution during energization is reduced, and recording can be performed with less unevenness. The configuration including the drive circuit when the recording head 12 is used is shown in FIG. 5, and has the same circuit configuration as the first embodiment.

By the way, when recording with an apparatus having the circuit configuration shown in FIG. 1 (or FIG. 5), the block-shaped electrode Ar (or Br)
and a stylus electrode χr (or Vr), recording is performed only when a signal is applied to both, and recording is not performed when a voltage is applied to only one of them; In other words, it is necessary to use the recording sheet 1 having a high recording threshold voltage. Figure 6(a)
8 shows the characteristics of the signal voltage E versus recording depth of the current-carrying heat-sensitive transfer sheet applied to the conventional recording system shown in FIG. The above-mentioned current-carrying (heat-sensitive) recording sheet exhibits ohmic resistance characteristics in both the conductive support layer and the recording layer. Therefore, the amount of heat generated is proportional to the square of the signal voltage, and the threshold for ink transfer is approximately 130 V. The voltage required to obtain a concentration D=1 is approximately 260V. Therefore, in the circuit configuration shown in Figure 1, if a voltage of +120V is applied to one of the stylus electrode and the block electrode and -120V is applied to the other for recording, one electrode is on and the other is off (grounded). (potential), no recording is performed, and only when both electrodes are on can recording be performed in the region in contact with the designated stylus electrode. In other words, by changing the setting to the voltage described above, the recording sheets 1 to 1 can be adapted to the recording apparatus of the present invention.

In addition, in order to obtain high recording density, 2. When applying a voltage close to the threshold voltage, there is a high probability that erroneous recording will be performed even when voltage is applied to only one electrode.

In order to prevent this, if the applied voltage is kept low, a problem arises in which the image density decreases. In a sheet with the characteristics shown in FIG. 6(a) above, if the voltage applied to each electrode is set to 100V to prevent erroneous recording, the density of the recorded image will be 0.
．． It will be around 6. Applying a slightly higher signal voltage to the block-shaped electrode than to the stylus electrode helps to improve the above-mentioned problem to some extent, but this alone is not a sufficient countermeasure. One effective solution to the above problem is to use an ink material with sharp temperature-viscosity characteristics. Figure 6(b) shows the recording characteristics when an ink with sharper temperature-viscosity change characteristics is used than that shown in Figure 6(a), and shows high recording performance without preventing the occurrence of erroneous information recording. It can be seen that the concentration can be obtained.

Another measure is to make the resistive properties of the ink layer and/or the conductive support non-ohmic. The ink layer and support layer are usually made conductive by mixing and dispersing carbon black, metal powder, or metal oxide in a resin material.
It is relatively easy to create non-ohmink resistance by controlling the dispersion state.

An example of a conductive particle dispersion exhibiting non-ohmic resistance characteristics is
For example, Japanese Patent Application Laid-open No. 53-31136 (U.S. Patent Application No. 70111)
3, June 30, 1976).

In the description on page 10 of the same document and in FIG. 6, the relationship between applied voltage and conductivity i5/cm of various toners having conductivity is described. Regarding the typical toner B shown in the same figure, this toner is contained in a resin containing about 5.
10-1325/c in an electric field of 102 V/cm with 0% by weight of conductive carbon uniformly dispersed.
m, but if the electric field is 103■/cm, then 1
The conductivity is 0-1225/cm, and further 104■
Toner A, shown in the figure as an example of a more conductive composition, has a conductivity of 10-56/cm in an electric field of 103 V/cm.
m, but in an electric field of 104 V/cm, it shows a conductivity of about 3
It exhibits a conductivity of X10-425/cm. In many cases, the rate of increase in conductivity tends to increase as the applied electric field increases, and this property is reflected in the thermal recording sheets 1 to 1 used in the present invention.
This is convenient for configuring.

Dispersed systems of conductive particles that have non-ohmic resistance characteristics usually exhibit high resistance at low voltages, and the resistance value decreases rapidly when the applied voltage is increased.

When the thermosensitive recording sheet has the above-mentioned non-ohmic characteristics, recording is sufficiently safely prevented due to the high resistance value when a signal voltage is applied to either the stylus electrode or the block-shaped electrode. Therefore, when signals are applied to both electrodes simultaneously, a high potential gradient is formed, the resistance value of the sheet is reduced, a large current flows, and a sufficiently high recording density of 1q is achieved. FIG. 6(C) shows the recording characteristics when using a sheet with non-ohmic resistance characteristics, and shows that the increase in recording density is promoted as the applied voltage increases, and the desired effect is achieved. Understand what you are getting.

Another means of obtaining non-ohmic characteristics can be achieved by providing a very thin barrier layer on the surface of the conductive support in contact with the recording electrode of the thermosensitive recording sheet and/or on the interface between the conductive support and the conductive ink layer.

A thin insulating film or a rectifying layer can be used as the barrier layer, and in either case, it has the property of blocking current flow at low applied voltages and losing its function of blocking current flow at high applied voltages. .

The method for improving the recording characteristics of a heat-sensitive recording sheet that is preferable to be applied to the present invention has been described above.The heat-sensitive recording sheet that is preferably used for the present invention has a recording threshold voltage that is suitable for obtaining images of normal density. Recording voltage required for 1/
It has a value of 2 or more.

Note that the present invention also includes a device in which the number of electrode sets is further increased.

The number of stylus electrodes belonging to each block voltage is
It is fine if there are more than one. Also, the order of designation of the common stylus electrodes is (χl-t), (Vz).

For example, instead of (χr2), (yl-2), ..., (χr
1), (Vrt), (χr3), (Vz).

(χrs), (Vrs), =・(χ1-2),
(Vr2), (χr4), (yr4), . . . may be used.

Note that the present invention is not limited to a method in which ink is melted by Joule heat and transferred to recording paper, but can also be applied to a method in which color is developed.

[Effects of the Invention] As described above, according to the present invention, a plurality of electrode sets are formed in which a plurality of stylus electrodes correspond to one block-shaped electrode, and these electrode sets are divided into groups of non-adjacent electrode sets. configuring the recording head using the same method, specifying one stylus electrode belonging to each electrode group at the same timing for each electrode group, and applying a recording signal voltage to each block-shaped electrode corresponding to the force. This makes it possible to simultaneously record a large number of pixels without interfering with each other, allowing high-speed, high-quality recording.

[Brief explanation of the drawing]

Figures 1 to 3 relate to the first embodiment of the present invention.
2 is a front view showing the recording head of the first embodiment, and FIG. An explanatory diagram showing how positions are recorded over time, FIG. 4 is a front view showing the configuration of a recording head in a second embodiment of the present invention, and FIG. 5 shows a thermal recording device of the second embodiment. 6 is a characteristic diagram showing the relationship between signal voltage and recording density of a thermosensitive recording sheet that can be used in the present invention, FIG. 7 is an explanatory diagram showing a conventional thermosensitive recording device, and FIG. An explanatory diagram showing a conventional thermal recording device, FIG. 9 is a front view showing the configuration of a recording head in the thermal recording device shown in FIG. 8.1.
...Thermal recording device 2.12...Recording head A1. B1. ..., ATl, Bη ... block-shaped electrode χ11 ・ χ12 ・ °°° χ+s, V++
, ..., Vns... Stylus electrode SR1, SR3... Shift register DR1, DR2, DR3... Driver circuit 0, Ω 0 "0

Claims (2)

[Claims] (1) A recording head consisting of a stylus electrode and a block-shaped electrode is brought into contact with a heat-sensitive recording sheet composed of a conductive heat-sensitive layer provided on a conductive support, and a signal voltage is applied between these electrodes to record heat. A thermal recording device that performs recording using Joule heat generated within a sheet includes a multi-stylus electrode in which a large number of stylus electrodes are arranged in a straight line, and a plurality of stylus electrode groups arranged close to the multi-stylus electrode. A plurality of block-shaped electrodes arranged so as to be divided form a plurality of electrode sets to which each stylus electrode group consisting of a plurality of stylus electrodes corresponds to each single block-shaped electrode, and these electrode sets are adjacent to each other. A recording head is formed into a plurality of electrode groups, which are arranged at a predetermined pitch apart from each other, and stylus electrodes belonging to the same electrode group but different from each other are connected to each other. means for forming a number of common stylus terminals equal to the product of the number of stylus electrodes constituting the stylus electrode group and the number of groups of electrode sets, and sequentially applying a predetermined voltage to these common stylus terminals in time series; and means for applying a recording signal voltage to each corresponding block-shaped electrode in the applied state. (2) The recording head includes one group of block-shaped electrodes arranged at appropriate intervals on one side of the multi-stylus electrodes arranged in a straight line, and each group of block-shaped electrodes arranged at appropriate intervals on the other side of the multi-stylus electrodes. The multi-stylus thermal recording device according to claim 1, characterized in that the multi-stylus thermal recording device comprises block-shaped electrodes arranged in a plurality of blocks, and a stylus electrode group in which the multi-stylus electrode corresponds to each of the block-shaped electrodes.