JPS5988773A - Magnetic recording method - Google Patents

Abstract

PURPOSE:To improve the resolution, by making the dot diameter of a magnetic latent image smaller than the diameter of exothermic resistive body elements by variably controlling an input to a heat sensitive head array or an external inversional magnetic field and combining magnetic latent images of such dot diameter. CONSTITUTION:In a heat sensitive head array 9 is arranged so that, for instance, exotermic resistive body elements 11 are realized 4dots/mm. are and is set under an oscillation- and displacement-free condition as shown by the arrow. When, for instance, recording is to be performed in a dot density of 8dots/mm. with a signal frequency of 5ms/line, the frequency and pulse width of picture electric signals are set so as to make the dot diameter 125mum. This signal frequency becomes 2.5ms/line which is two times of that at the time of 4dots/mm. and the oscillation frequency of the heat sensitive head array 9 becomes 1/5ms. Therefore, only half of a magnetic latent image 12 is formed and, after the heat sensitive head array 9 oscillates, the remaining half of the latent image 12 is formed in such a manner that the blank part of the image 12 is filled with the latter half, and thus recording of 8dots/mm. is performed. Therefore, the resolution can be improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic recording method, and more particularly to a magnetic recording method by thermomagnetic writing using a heat-sensitive RAD array.

[Prior art] Conventionally, as a @ki recording method, the example shown in Fig. 1 (eLl
As shown in the figure, after a magnetic recording body (3) comprising a ferromagnetic layer (2) of Tb-Fe etc. provided on a substrate (1) of glass etc. is uniformly magnetized by a magnet (4), Figure 1 (As shown in Figure 1), heat is applied to the image area from a heat source (5) to raise the ferromagnetic layer (2) in that area to a temperature higher than the Curie point, lowering the coercive force Ha in that area and magnetizing it. While eliminating the magnet (6)
A thermomagnetic recording method is known in which a magnetic latent image is formed by applying an external magnetic field in the opposite direction to remagnetize the image area during the cooling process to room temperature. It is also known that this method can be applied to printers; as shown in Figure 1 (C), when a magnetic toner (7) is rubbed on a magnetic latent image, this magnetic toner (7) is
is attached to the magnetization reversal portion, and it is good to transfer and fix this. Here, it is known to use a thermal head array as the heat source (5). Also,
Although the ferromagnetic layer (2) in FIG. 1 is for perpendicular recording using Tb--Fe or the like, longitudinal recording using Cr(h or the like) is also known.

However, when I look at the heat sensitive RAD array, it is currently showing 8 dots/
m resolution, it is structurally difficult to further increase the resolution, and the higher the density, the higher the cost.

〔the purpose〕

The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic recording method that can achieve higher resolution while utilizing the current heat-sensitive RAD array.

〔composition〕

Embodiments of the present invention will be described based on FIGS. 2 to 7. First, as a result of conducting a writing experiment using a thermal head, the following was found.

In other words, when the magnitude of the current applied to the thermal head is changed, or when the current is kept constant and the current applied time is changed, the size of the written magnetic latent image changes, and the energy (=(current)
The larger the value of x (current application time), the larger the dot diameter. This is thought to be due to the temperature distribution in the magnetic recording body under the thermal head, with the temperature of the portion of the magnetic recording body near the center of each heating resistive element of the thermal head being higher and lower toward the periphery. Similarly, the temperature of the heat-sensitive head itself is lower toward the center of each heating resistive element, and lower toward the periphery. If there is a temperature difference like this, the coercive force He
The coercive force He is low in areas where the temperature is high and magnetization is easily reversed. Therefore, if the amount of energy applied to the thermal head or the strength of the reversing magnetic field applied from the outside changes, the dot diameter of the magnetic latent image formed will change, an example of which is shown in Figure 3. It will be done.

According to these experimental results, on the other hand, it is important to appropriately select the amount of energy applied to the thermal head or the strength of the reversal magnetic field, so that the magnetic dot has an appropriate diameter that is smaller than the diameter of the heating resistor element in the thermal head. This means that latent images can be formed freely.

Therefore, the present invention focuses on such points, and in order to compensate for the structural limitations of increasing the resolution of heat-sensitive RAD arrays, the present invention basically develops heat-sensitive RAD arrays based on the characteristics shown in FIG. By variably controlling the input to or the external reversal magnetic field to make the dot diameter of the magnetic latent image smaller than the diameter of the heating resistor element of the heat-sensitive RAD array, and by combining the magnetic latent images with such dot diameters, This makes it possible to achieve even higher resolution.

Now, a concrete example is shown in Figs. 4 to 6. A heat-sensitive RAD array (9) and a magnet αQ serving as a magnetic field generation source are provided inside and outside the drum-shaped magnetic recording body (8), and the heat-sensitive RAD array (9) is shown in FIG. For example, the heating resistor element (11) has 4 dots/
w, that is, J = 0.5 wax, and this heat-sensitive RAD array (9) is set to be able to swing freely as shown by the arrow in Fig. 4. If signal information of 4 dots/m is input in this state, a magnetic latent image of 4 dots/m is formed according to the conventional heating resistor element αV.
Now, let us consider a case where, for example, it is desired to record 8 dots/gourd (that is, dot diameter 125 .mu.) in 5 m, 5 Z rows. In this case, the input to the thermal head play (9) is controlled and set so that the dot diameter is 125 .mu. from the thermal energy-dot diameter relationship diagram of FIG. 3 described above. here,
Setting means that it is designed in advance in the actual device and can be switched with a single button. Accordingly, the frequency of the image electric signal applied to each heating resistor element αη,
Pulse width is set. This pulse width has a dot diameter of 1
It is determined from the relationship diagram that it will be 25 μ, and the signal frequency is b times that of 4 dots) 7W, 2.5 m s 7
The oscillation frequency of the thermal array (9) is 15.
mm=200Hz. Therefore, first of all, Fig. 6 (a
As shown in +, half of the magnetic latent image (6) is formed, and then, after the RAD array (9) is swung to the heat-sensitive surface, the remaining half of the magnetic latent image (6) is formed in between as shown in Figure 6 (south). 8 dots)/tsm are recorded. In addition, in FIG. 6, to show the correspondence relationship, A1, El
It is indicated with a subscript such as .... As a result, the thermal radiation array (9) was 8 dots/1.16 dots/slI.
If it is the same, it becomes possible to achieve higher resolutions of 16 dots/constant and 32 dots/W, respectively.

Figure 7 shows the other side, one coil (not shown).
A head is used in which two heat-sensitive RAD arrays (91 x 9 g) are arranged in two rows, shifted by a predetermined amount. Therefore, when recording at 4 dots/square, only the thermal head array (91) is used, and when recording at 8 dots/square, two thermal head arrays (91) are used by pressing the switch button.
At the same time as (9g) is used, the pulse width can be changed as in the previous example. High resolution is achieved by a combination of magnetic latent images (12A1) (tZAX), etc., which are modeled and shown with diagonal lines in FIG.

In addition, in order to reduce the dot diameter, a heat-sensitive RAD array (
The input on the 9) side may be constant, an electromagnet or the like may be used as the magnet αq, and the intensity of the external reversal magnetic field may be controlled to be varied.

〔effect〕

In the present invention, as described above, the input to the heat-sensitive RAD array or the magnetic field from the magnetic field generation source is variably controlled to make the dot diameter of the magnetic latent image smaller than the diameter of the heating resistor element of the heat-sensitive RAD array. Even if the current heat-sensitive RAD array is used, a much higher resolution can be achieved by combining magnetic latent images with smaller dot diameters.

[Brief explanation of drawings]

FIG. 1 (a1-(Ol is an explanatory diagram showing the thermomagnetic recording method,
Figures 2 to 7 show examples of the present invention, Figures 2 and 3 are characteristic diagrams showing measurement results, Figure 4 is a front view, Figure 5 is a side view, and Figure 6 is a characteristic diagram showing measurement results. (a) (The town is an explanatory map,
FIG. 7 is an explanatory diagram showing the other side. 9... Heat-sensitive Radar array, 10... Magnet (magnetic field generation source), 11... Heating resistor element, 12... For magnetic latent image Applicant Ricoh Co., Ltd. Procedures Amendment (spontaneous) December 28, 1981 Japanese Patent Application No. 198765 2 Name of the invention Magnetic recording method 3 Relationship with the case of the person making the amendment Patent applicant 4 Agent 〒107 None 6 The specification to be amended shall be amended 12 times.

Claims (1)

[Claims] In this magnetic recording method, thermomagnetic writing is performed using a heat-sensitive RAD array and a magnetic field source that provides an external reversal magnetic field.The dot diameter of the magnetic latent image is determined by variable control of the input to the heat-sensitive RAD array or the magnetic field from the magnetic field source. A magnetic recording method characterized in that the diameter of the heat-sensitive RAD array is smaller than the diameter of the heating resistor element.