JPS6038705A - Thermomagnetic recorder - Google Patents

Abstract

PURPOSE:To improve a magnetic latent image and also to increase the recording speed by limiting the size and the space ratio of a heating area consisting of heating elements less than the specific value respectively when a magnet performs magnetization in a certain direction and the other magnet performs magnetization in the opposite direction to the first magnetization. CONSTITUTION:A magnet 7 performs the even magnetization in a certain direction, and a magnet 42 impresses an even magnetic field to the area of a thermomagnetic recording medium 1 which is heated by a heating head 3 in the opposite direction to the magnet 7. Then the heating value (longer diameter) and the space ratio (d+vXt)/{vXT1-(d+vXt)} of the heating elements are set under 20 on the medium 1 in the carrying direction of the medium 1. Thus the picture quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermomagnetic recording device that forms a magnetic latent image on a magnetic recording medium using heat.

Roughly detailed, the present invention provides a magnetic recording medium selection rotor force A and a station Bll rotor l in a uniform magnetic field.
The present invention relates to a thermomagnetic recording device that forms a magnetic latent image of a self-recorded image on a magnetic recording medium by heating the heated portion and making the magnetization pattern τ of the heated portion different from that of the heated portion.

Conventionally, as a method for forming a magnetic latent image, a recording current corresponding to the image (No. 8) is passed through a magnetic head placed in contact with the magnetic latent image. It is commonly known that magnets can be magnetized both centrally and locally, and has been widely put into practical use.

In order to form a magnetic latent image over the entire image width on a sheet-shaped magnetic recording medium using such a magnetic head, one or more magnetic heads are prepared, and the direction of movement of the magnetic recording medium is It is necessary to perform magnetic recording using both sub-scanning along the direction and main scanning in the direction perpendicular to the direction.

Such conventional methods (1) require precise driving and control methods to keep the main scanning interval constant;
(3) Furthermore, for image formation such as development and transfer, it is necessary to move the magnetic recording medium at low speed.

Therefore, in order to satisfy the above-mentioned requirements, a precise drive mechanism and control means that can correspond to these various operation modes are required. This not only increases the price but also makes it difficult to improve reliability.

Furthermore, as a measure to improve the above-mentioned drawbacks, it has been proposed to use so-called multi-magnetic rad full arrays that are arranged at high density over the entire image width to satisfy the required resolution of the reproduced image.

However, in this multi-magnetic RAD array, in order to increase the resolution, it is necessary to provide narrow tracks of about 100 μm or less at intervals of about 100 μm. Moreover, in order to reduce the recording current, one coil is required for each one-rack because of the plurality of turns.

In this way, it requires a complex structure of f2 in 1 (yoh)
, the probability of causing electromagnetic interference between adjacent devices 1/X, etc.Q
), it is considered difficult to realize such a multi-magnetic field array.

In addition to the conventional technology using a magnetic head, it has also been proposed to eliminate the thermomagnetic recording method based on the thermoremanent magnetization phenomenon. This thermomagnetic recording method uses a thermomagnetic recording medium whose magnetic properties change depending on temperature.

That is, it is decided to partially demagnetize the recording medium by partially applying heat to the recording medium that has already been magnetized, or by heating the recording medium to a temperature higher than one Curie temperature.
At the same time as applying heat to the unmagnetized recording medium,
Magnetic recording is performed by applying a magnetic field from the outside and selectively magnetizing the heated portion.

Known heat application means in this case include a focused laser beam, flash light, or a heating head in which finely separated resistance heating elements are arranged in one or more rows. Further, a magnetic head is used as a means for applying a magnetic field.

In such a thermomagnetic recording method, (1) strong thermal energy is applied locally, which tends to cause thermal deformation of the recording medium; and (2) a considerable capacity is required for the heat application means such as a laser. (3) Furthermore, since the gap between the magnetic heads is generally narrow, it takes a lot of precision and effort to align the part of the thermomagnetic recording device heated by the heating head and the magnetic head gear 1? There were some inconveniences, such as the need to use it.

The object of the present invention was made in view of the above-mentioned circumstances, and the object is to eliminate the various inconveniences mentioned above with a simple structure using only two magnets and a heating head. An object of the present invention is to provide a thermomagnetic recording device.

In order to achieve the above object, the present invention provides the first
The thermomagnetic recording medium is uniformly magnetized in one predetermined direction within its plane by the magnet, and then the thermomagnetic recording medium is locally and selectively heated by the heating head in accordance with the image signal. At the same time, a uniform magnetic field in the opposite direction to the one direction described above is applied to the heated portion by a second magnet, so that the thermal residual magnetism in the heated portion is in the opposite direction to that of the remaining portion. (b) In this case, the ratio of the length of the heat generating area of each heat generating element to the interval, 111, is set to 20 or less.

An outline of an embodiment of the thermomagnetic recording device of the present invention is shown in FIG.

At J3 in FIG. 1, the thermomagnetic recording medium 1 includes a heating resistor 2.
It is sandwiched between a heating head 3 having a roller and a backup roll 4, and is conveyed in the direction of arrow 9 while being in close contact with both of them.

The backup mill 4 includes an outer non-magnetic sleeve 41 that can follow the thermo-magnetic recording medium 1 and rotate at the same circumferential speed, and is built into the non-magnetic sleeve 41 and rotates around the thermo-magnetic recording medium 1. It consists of a magnet 42 as a means for generating a uniform magnetic field at a portion in contact with the heating resistor 2. This sleeve 41 can be made of aluminum or stainless steel.

Further, along the transport path of the thermomagnetic recording medium 1, a magnet 7 is arranged upstream of the heating head 3 as a means for generating a uniform magnetic field in the opposite direction to the uniform magnetic field produced by the magnet 42. There is. Formation of a magnetic latent image according to this embodiment is performed as follows.

As the thermomagnetic recording medium 1 is conveyed in the direction of arrow 9, it is magnetized by magnet 7 so as to have a uniform magnetization pattern from right to left, as shown by arrow 5 in FIG. Ru. For this reason, the magnetic flux leaking from the thermomagnetic recording medium 1 becomes almost zero, and the upper surface 1i) is in a demagnetized state.

When the thermomagnetic recording medium 1 is conveyed to the heating head 3, a signal 8 corresponding to the image is applied to each heating resistor 2 of the heating head 3. Resistor 2 generates heat.

Directly below the heating head 3, a backup roll 4 is arranged so as to face the heating head 3 and sandwich the thermomagnetic recording medium 1 therebetween. The magnet 42 built into the backup roll 4 is! j67 and the magnetic field in the opposite direction to the thermomagnetic recording medium 1.
It occurs along the surface of However, in FIG. 1, as shown by arrow 6, a uniform magnetic field is generated from left to right.

Therefore, under the influence of the uniform magnetic field 6 due to this magnet 42,
The temperature rises due to the heat generated by the selected heat generating resistor 2 in the heating head 3, and a magnetization pattern is created by the thermoremanent effect only in the portion of the thermomagnetic recording medium 1 that is sufficiently hot and corresponds to the image information. is formed.

The direction of the magnetization pattern is also from the left in FIG. 1, and can be distinguished from the magnetization direction of other parts, so that a magnetic latent image corresponding to the image signal 8 is formed.

Next, a specific example of the thermomagnetic recording device used in the experiments by the present inventors will be described.

In FIG. 1, the thermomagnetic recording medium 1 is made of a polyimide film with a thickness of 75 μm as a base layer, and on which chromium oxide (Cr02) particles are added at a ratio of about 30% (volume ratio) to have a high heat resistance. It is made by applying a suspension (slurry) dispersed in a molecular resin (boaryarylate) to a thickness of approximately 5 μm.

The sample was cut into a sheet having a width of 4001IIIn and a length of 1000 mm, and was shaped into a thermomagnetic recording medium.

The magnet 7 only needs to generate a magnetic field strong enough to uniformly magnetize the thermomagnetic recording medium 1, and the magnet 7 prepared by the present inventors is a bar magnet or a magnetic field with a surface leakage field of about 2000 oersteds. It was a horseshoe magnet.

The magnet 42 is also a bar magnet or a horseshoe magnet, and the strength of the magnet and the thickness of the sleeve 41 are determined so that a leakage magnetic field of about 100 eels is generated on the heating head side surface of the thermomagnetic recording medium 1.

The sleeve 41 is a cylindrical body made of aluminum, and its periphery is coated with silicone rubber having a rubber hardness of 45° in order to stabilize the conveyance of the thermomagnetic recording medium 1, although not shown.

Further, the magnet 42 is fixed so as not to move within the sleeve 41, so that only the outer non-magnetic sleeve 41 rotates following the movement of the thermomagnetic recording medium 1 in the direction of the arrow 9.

The heating head 3 is an alternating lead type print head having a heating resistor 2 in the form of a thick film band. A schematic structure of the heating resistor 2 is shown in FIG. 2. In FIG. 2, 21 is a lead wire drawn out alternately to both sides of the heating resistor 2. A heating head having such a structure is known as a heat-sensitive recording head.

The heat generating resistor 2 used in the experiments by the present inventors is subdivided into 2048 heat generating elements (corresponding to pixels) by respective lead wires 21. The individual dimensions of each heating element are 0.07ImxQ, 25. n+m, the average pitch of the array is 0.125 mm, and the printing line density is 8 dots/m.
It is nl. Also, the average resistance value of the heating element is approximately 300Ω
Met. The recording dimension -J of such a heating resistor 2 is 256 man.

An example of a drive circuit for the heating head 3 is not shown in FIG.

In this figure, the heating resistor 2 is connected to each heating element 2-1゜2-2.
．． It is shown divided into... Each unidirectional element 15-1.15-2. . . . are connected between one of the two power terminals A and B and every other lead wire of each heating element.

The picture signal supply circuit 16 is connected to a shift register 16A connected to the picture signal terminal 18, and is provided corresponding to each phase of the register 16A to the shift 1, and supplies the picture signals and Block selection strobe lines 5TR1, 5T
A large number of AND circuits 16B that receive one signal of R2 as input.
-1,16B-2°... Consisting of.

In addition, each AND circuit 16B-1, 16B-2゜...
The outputs of . . . are connected to every other remaining lead wire of each heating element, as shown by C-1, C-2, . . .

Although not shown in the figure, in the experimental equipment of the present inventors, the shift register 16A had a total of 8 blocks, each consisting of 128 bits grouped together into one block.

In other words, the power terminal A side is ON and the power terminal B side is OFF.
F's I'! Recording of 128x8 bits corresponding to every other heating element, which is half of the total, is performed on i, while the power terminal B side is ON and the A side is OFF.
At the same time, recording of the remaining half of 128×8 bits is performed, so that recording of one line consisting of a total of 2048 bits is completed.

The shift register 16A is also provided with a data terminal 18 and a clock pulse terminal (not shown) for reading both signals in each of the eight blocks.

Incidentally, such a heating resistor drive circuit is already known (see, for example, Japanese Patent Application No. 56-201004).
.

The operation of the above-mentioned heating resistor drive circuit will be explained based on Quimchar 1- in FIG. 4. Note that the frequency of the clock pulse is 250 KHz.

First, the power supply terminal A side is turned ON, and a control signal (not shown in the figure) is input such that the B side becomes 0 and F. At time t1, when the clock pulse CP (Figure 4A) is input, the time series The part from time [1 to t2] of the serial data (B in the same figure) is transferred from the image signal terminal 18 to the shift register 16A.
(C in the same figure) 0 The data m to be transferred during this interval is, as can be easily understood from the above, one pixel of one line. 1 corresponding to the image signal 1 28 x 8 pits - that is, 1
024 bits.

83 at time t2 when the data transfer/input operation ends.
and block selection strobe lines STR1 and 5T.
Strobe signals are sequentially input to R2. As a result, the A block connected to the shift register 16A,
The 1024-bit thermal element is driven, and every other pixel in one line is recorded according to the input signal (D in the same figure).Next, the power terminal B side is turned on, and the A side is turned on. A control signal (not shown) is supplied to turn the switch OFF. Then, at time t3, when the clock pulse CP is input (FIG. 4A), the portion from t3 to 14 of the time-series serial data is transmitted from the image signal terminal 18 to all blocks of shift 1 to register 16A. and is input (E in the same figure).

In exactly the same way as described above regarding power supply terminal A, when strobe signals are sequentially input to block selection strobe lines 5TR1 and 5TR2, register 1 is input to shift 1.
The remaining every other pixel of one line connected to 6A is recorded according to the signal (see "
〉.

As is clear from the above description, in the heating head drive method described above, one line is divided into two blocks, A and B, and printed alternately.

Therefore, the transfer time to the shift register 16A is 1
Assuming 4 μsec per bit, the transfer time of print data for each block to the shift register 16A is 4, czsec x i Q24 (bit) - 〇,
It becomes 512 msec.

The time required to print only the A block in its entirety is 2.
512n+ sea. Therefore, it takes about 5.5111 SeC to print both blocks A and 8 to completely form one line.

From the above, the time required to print one line is 6.
When specified as IIISeC, the time required to print one sheet of A4 size paper (length 297 mm) using a heating head with a resolution of 8 dora 1~/mm (6n+5ecx
8 dots - x 297 mm = 14.3 (seconds).

Now, the magnetic latent image formed on the thermomagnetic recording medium as described above is developed with magnetic toner and made into a visible image (toner image) by a known method. Then, by similarly known means, the developed image is transferred to plain paper and fixed, thereby completing the recording.

In this way, it was confirmed that by using a thermomagnetic recording device as shown in Figure 1, it was possible to convert and record a time-series electrical image signal into a visible image using a magnetic method. It was done.

By the way, the present inventors have discovered that when performing thermomagnetic recording, the heating conditions of the heating head - that is, the duty of supplying electrical energy to each heating resistor element - have a large effect on the quality of the resulting image. This was revealed through experimental studies by et al.

In the above-mentioned experiment, the present inventors set the resistance value of each heating element as the heating resistor 2 of the heating head 3 to 300.
0 was selected and used.

The voltage applied to each heating element is variable from 10V to 2'5V, while the driving time of each block A and B is as follows:
It was variable from 0.05m5ec to 5m5ec.

Also, considering that the time required to print both blocks A and 8 to completely form one line is called one line recording time, the recording performance of one line is from 1m5ec to 20m5
I made it variable up to ec.

In the experiments conducted by the present inventors, when forming a full magnetic field on the thermomagnetic recording medium 1, the thermomagnetic recording medium 1 was continuously conveyed using an ordinary AC motor, so that the heating resistor 2 It is being driven when it is moving.

Therefore, the shape of each driver 1 to form a latent image on the thermomagnetic recording medium 1 extends for a long time in the conveyance direction of the thermomagnetic recording medium 1, so that the resolution and sharpness of the image are not impaired. is expected.

However, the inventors' experiments have confirmed that by appropriately combining the 1-block driving time, the 1-line recording time, and the recording medium conveyance speed, the influence on image quality can be almost eliminated.

The dot shape extends long in the conveyance direction of the recording medium,
The relationship with the dot spacing will be explained in more detail with reference to FIG.

In FIG. 7, while the recording medium is stopped, electric energy is supplied to the heat generating resistor to print, and the diameter of the heat generating area of 1 dot 1- is assumed to be d. It is assumed that the heat generating area of each of the drums 1 to 1 when stopped is approximately circular.

1 block driving time and 1 line recording performance
Assuming that 2 dots are 1 and the continuous conveyance speed of the recording medium is ■, the heat generating area of each dot is, in the conveyance direction, the traveling valve of time -
1, that is, it extends for the length of (vxt).

Therefore, the major axis of the entire heat generating area is (d + V
t). Since the same dot as mentioned above starts to be driven next time after T1 time, during this time the recording medium becomes (vxT
l) will be transported. Therefore, the interval between the heat generating regions is v x Tl - (d + v xt ).

If the major axis of the heat-generating regions is too large and the interval between the heat-generating regions is small, this means that the duty of applying heat to the thermomagnetic recording medium is large, which means that heat accumulation phenomenon is likely to occur.

On the other hand, if the major axis of the heat generating regions is small and the interval between the heat generating regions is large, the duty of applying heat to the thermomagnetic recording medium is small, and the interval between the heat generating regions becomes long.
This means that heat accumulation phenomenon is less likely to occur.

Among the conditions for supplying electrical energy to the heat generating resistors of the heating element array, the present inventors focused particularly on the length of the spacing between the heat generating regions of a specific heat generating element (dragon). By changing the conditions, a magnetic latent image is formed, and then it is developed and transferred to recording paper using the usual method.
Fixing was carried out (1. The size and long axis of the heat generating area on the magnetic recording medium) and the effects of the mutual spacing on the image quality were examined in an experiment.

In this case, the conveyance speed is 5 mm/sea,
J: Sea urchin variable up to 200 mm/sec.

According to the study of the experimental results, the size of the heat generating area, that is, the ratio of the major axis to the interval (d + v, x Tb) / (v x Tl - (d + TL))) is 2.
It was found that a good image was formed when the value was 0 or less.

Additionally, it has been found that when this ratio is set to 5.0 or less, even better images can be obtained.

That is, when this ratio is set to 20.0 or more, a heat accumulation phenomenon appears in the chopsticks. As a result, the shape of the recording dots may be disturbed, and the thermomagnetic recording medium 1 may exhibit thermal deformation (unevenness) and alteration of magnetic properties (for example, disturbance of the orientation of magnetic particles due to melting of the binder). This causes cleaning failure and ii! +7 This causes stains in the background of the image and defects in contrast 1 to last.

For example, the applied voltage is 12V, the distance between 1 block drive 114 is 1.5m sec, and the recording time of 1 line is 6m.
sec, and the conveyance speed is 39 null/sec, the ratio of the length of the heat generating area (longer axis) to the interval is approximately 3.
It is 5.

The image obtained by forming a magnetic latent image under these conditions had an excellent image density of 1.2 or more and a background density of 0.01 or less. In addition, the image in this case has no density unevenness or missing parts from Dra 1.
It was extremely clear and of good quality.

As detailed above, a good image was obtained in the above example, but there is a possibility that the magnitude of the energy applied to each heating element may affect the numerical range of the ratio. be.

In order to confirm this, the present inventors repeated the same experiment as described above while changing the applied energy.

In this case, the energy applied to each heating element is defined by the following equation.

2 Enee xt (m joules/dot) However, in the above formula, the energy applied to each heating element is E1, the applied voltage is (■), and the resistance value of the heating element is R. Also, the unit of applied energy E is 1 dot 1 ~ (1
It is expressed in millimeters (m nojoules) per heating element).

Sat) Using formula 10, T, R = 300Ω, -5 to 30V,
By substituting and inverting the values of t = 0.05 to 5 m sec, each record collection is determined! The value of the applied energy E, which is equal to J3, has become clear.

According to the inventors' experiments and test results, the applied energy value ranged from 0.05 mjoules/dot to 201 mjoules/dot.
It has been found that a good image as described above can be formed by setting the above-mentioned ratio value to 20 or less, especially 5 or less. Ta.

However, if the applied energy is less than 0.05 IIl joule/dot, there will be an insufficient amount of heat, and sufficient heat will not be transmitted to the thermomagnetic recording medium 1, and the thermoremanent effect will not occur, making it impossible to form an image.

On the other hand, when the applied energy is 2111 units/dot or more, the thermomagnetic recording medium 1 undergoes thermal deformation (unevenness) and changes in magnetic properties (for example, disordered orientation of magnetic particles due to melting of the binder). This can lead to poor cleaning, resulting in hack-ground stains and poor contrast in the image.

In addition, the range of the stamped neck is as follows:
It has also been found that the optimum range is between 0.2 mm Joule/Dora and 1.0 m RegiCold.

For example, if the applied voltage is 13V and the driving time of one block is 1
In the case of m sec, the energy applied to the heating resistor 2 is approximately 0.5611 joule/dot. The image obtained by adding this condition to the numerical condition of the ratio and forming a magnetic latent image has an excellent image density of 1.2 or more and a background density of 0.01 or less. Ta. Furthermore, the image in this case was extremely bright and of good quality, with no density unevenness or missing dots.

The above-mentioned numerical range d3 of the ratio of the size and major axis of the heat generating area to the interval and the numerical range of the applied energy in order to obtain good image quality are the values for the thermomagnetic recording medium 19, the heating resistor 2, or the heating Thermal characteristics of the head 3 etc. (e.g.
It has been confirmed from the results of experiments conducted by the present inventors that even if the thermal conductivity, thermal diffusivity, specific heat, etc.) are changed within a practical range, there is no effect on the heat distribution.

In this way, a good image was obtained in the above-mentioned Example 7j, but the present invention is not limited to the above-mentioned example, and various modifications as described below are possible.

(1) The magnetic material used in thermomagnetic recording media is chromium oxide (
The material is not limited to Cr 02 ), but any ferromagnetic material having a relatively low Curie temperature or compensation temperature and sufficient heat resistance may be used. Therefore, To-Fe system, Gd
-C0 system (D b (f) lfi can be used.

(2) The magnet that generates the uniform magnetic field may be either a permanent magnet or an electromagnet, and its shape may be arbitrary, such as a bar magnet or a horseshoe magnet.

(3) In the embodiment shown in FIG. 1, the magnet 42 placed below the heating head 3 via the thermomagnetic recording medium 1 will be as shown in FIGS. As shown in FIG. 3, there is no problem even if a3 is placed directly above the heating head 3. Note that in FIGS. 5 and 6, the same reference numerals as in FIG. 1 represent the same or equivalent parts. 10A, 10B1
．． This is a magnet that replaces the magnet 42.

(4) In the above embodiment, the heating resistor 2 of the heating head 3 is divided into two blocks and driven, but other driving means may be used as necessary. For example, data may be input in parallel throughout the entire system, and then the heating resistor 2 may be driven at once. By connecting a circuit, such as a latch circuit, data input and output can be performed in parallel. By covering in this way, it becomes possible to shorten the processing time 11!1 and perform high-speed recording.

As described above, the present invention achieves the following outstanding effects.

(1) The ratio of the size and length of the heat generating area to each drum 1 and the distance between them, which can form a good magnetic latent image;
In addition, since we were able to experimentally limit the numerical range of the applied energy, we were able to obtain clear, clean, and good images with less background smearing by using an extremely simple configuration consisting of two magnets and a heating head. We were able to realize a thermomagnetic recording device that can.

(2) Heat can now be efficiently applied to the thermomagnetic recording medium, and the problem of deformation and deterioration of the recording medium due to excessive heat supply can be solved by reducing the energy applied to the heating resistor within the above range. I was able to solve it by doing this.

(3) Increasing the speed of recording was also achieved by lowering the voltage and shortening the driving time while maintaining the applied energy value within the above range.

(4) If the magnets 42.10A and IOB are made of bar magnets or horseshoe-shaped magnets, the area covered by the generated magnetic field will be widened, making it easier to align these magnets with the heating resistor 2, making it easier to assemble the magnets. The required accuracy can be lowered.

(5) Since the thermomagnetic recording medium is continuously transported, the transport (I) can be simplified.

[Brief explanation of drawings]

FIG. 1 is a side view showing a schematic configuration of a thermomagnetic recording device according to an embodiment of the present invention, FIG. 2 is a plan view showing a schematic configuration of a heating resistor of a heating head suitable for implementing the present invention, and FIG. The figure is a block diagram showing an example of a drive circuit for a heating resistor suitable for implementing the present invention, and FIG. 4 is a timing chart for explaining the operation of FIG. The figures are respectively side views showing essential parts of other embodiments of the present invention, and FIG. 7 is a diagram showing the relationship between the length and length of the heat generating area in the same drum 1 and the spacing. . 1...Thermomagnetic recording medium, 2...Heating resistor, 3...
・Heating head, 4...Backup roll, 41...
・Non-magnetic sleeve, 42, 7... Magnet agent Patent attorney 1 person other than the model expert Figure 1 Figure 2 Figure 1 Figure 3 World 1b C

Claims (5)

[Claims] (1) Includes a heat generating resistor consisting of a large number of heat generating elements arranged so as to be in contact with the recording surface side of a continuously conveyed thermomagnetic recording medium and locally and selectively heats the medium. a heating head, means for supplying electrical energy to each of the heating elements according to the image month, a backup roll for pushing the thermomagnetic recording medium toward the heating head, and conveying the thermomagnetic recording medium. a first magnet that is disposed upstream of the heating head along the path and uniformly magnetizes the thermomagnetic recording medium in one direction within its plane; and the thermomagnetic recording medium is heated by the heating head. In a thermomagnetic recording device comprising a second magnet that applies a uniform magnetic field in a direction opposite to the one direction to a portion of the thermomagnetic recording medium, each heating element generates a magnetic field on the thermomagnetic recording medium in the transport direction of the thermomagnetic recording medium. 1. A thermomagnetic recording device characterized in that the ratio of the length of the heat generating area (longer axis) to the interval is in the range of 20.0 or less. (2) The thermomagnetic recording device described in the patent, wherein the backup roll includes a non-magnetic sleeve and a second magnet fixed inside the sleeve. (3) The thermomagnetic recording device according to claim 1, wherein the backup roll is a non-magnetic sleeve, and the second magnet is disposed on the side of the heating head. (4) The heat generating area according to any one of claims 1 to 3, characterized in that {ic+, which is a ratio between the size and major axis of the heat generating area and the interval, is 5.0 or less. Magnetic recording device. (5) A heating head that includes a heating resistor made up of a large number of heating elements, which is arranged so as to be in contact with the recording surface side of a thermomagnetic recording medium that is continuously conveyed, and is used to locally and selectively heat the medium. a means for supplying electrical energy to each heating element according to an image signal; a backup roll for pressing the thermomagnetic recording medium toward the heating head; a first magnet that is disposed upstream of the head and magnetizes the thermomagnetic recording medium in one direction within its plane; and a second magnet that applies a uniform magnetic field in the opposite direction! ! ! !
In the magnetic recording device, the value of the ratio of the length of the heat generating area on the thermomagnetic recording medium by each heating element in the transport direction of the thermomagnetic recording medium to the interval is 20.
0 or less, and the electric energy supplied to each heating element is in the range of 0.05 millijoule to 2.0 millijoule per dot l. 6 Electrical energy supplied to each heating element J legy force-11
n:J Nishii! is characterized by being in the range of 0.2 millijoules to 1.0 millijoules per dotu 1. Q<
A thermomagnetic recording device according to claim 5.