JP3381889B2 - Recording method and recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method and a recording apparatus for repeating recording and erasing on a rewritable reversible thermosensitive recording medium, and more particularly to prevention of erasing failure when repeatedly recording and erasing.

[0002]

2. Description of the Related Art In recent years, as disclosed in, for example, Japanese Patent Laid-Open No. 4-44887, a reversible thermosensitive recording medium capable of reversibly changing transparency depending on temperature and repeatedly recording and erasing information has been developed. , Has begun to be used to display various information. This reversible thermosensitive recording medium 1 has a polymer 32 and an organic low-molecular substance 33 in a polymer 32 on a base film 31 made of a polyester film or the like, as shown in the configuration diagram of FIG.
A recording layer 34 made of a polymer / low-molecular composite type recording material in which is dispersed is provided, and an overcoat layer 35 is provided on the recording layer 34 to protect the recording layer 34. The recording material forming the recording layer 34 of the reversible thermosensitive recording medium 1 changes in transmittance when heated and cooled, as shown in FIG. For example, a room temperature state A below the temperature T ₁ shown in FIG.
When the recording material in the cloudy state is heated at ₂ , the transmittance starts to increase from the temperature T ₂ and reaches the maximum transparent state B at the temperature T ₃ . The transparent state is maintained even in the state C in which the recording material is cooled to room temperature in the maximum transparent state B. Next, as shown by the broken line in FIG. 7, the recording material which is in the maximum transparent state at room temperature C is in a state D at a temperature T ₄ or higher higher than the temperature T _3.
When reheated to, it becomes an intermediate state between the maximum transparent state and the maximum cloudy state. When the state D is cooled to the room temperature state A at the temperature T ₁ or lower, the original maximum cloudiness is restored. The reversible thermosensitive recording medium 1 can repeat recording and erasing of a visible image by utilizing the property that the organic low molecular weight substance 33 of the recording material changes from polycrystal to single crystal due to heat to change the transmittance. it can.

A recording apparatus for repeatedly recording and erasing a visible image on the reversible thermosensitive recording medium 1 is disclosed in, for example, Japanese Patent Laid-Open No. 5-4446.
It is disclosed in the publication. As shown in FIG. 8, the recording apparatus shown in Japanese Patent Application Laid-Open No. 5-4446 has a thermal head 6 for erasing and a thermal head 5 for recording, and has a transport roller 3
The reversible thermosensitive recording medium 1 sent by the platen roller 4 and the position detecting sensor 3 in front of the thermal head 6 for erasing.
6, when the reversible thermosensitive recording medium 1 reaches the clearing temperature of the reversible thermosensitive recording medium 1 immediately before the reversible thermosensitive recording medium 1 reaches the erasing thermal head 6, when the clearing temperature is reached. A pulse current is passed through the erasing thermal head 6 to maintain the clearing temperature to clear the recording layer of the reversible thermosensitive recording medium 1 to erase the cloudy visible image. After that, a new visible image is written on the reversible thermosensitive recording medium 1 by the thermal head 5. By repeating this operation, the reversible thermosensitive recording medium 1 can be used any number of times. In addition, the reversible thermosensitive recording medium 1 sent by the transport roller 3 is detected, and the erasing thermal head 6 having a small heat capacity is rapidly heated to erase the visible image. Miniaturization and energy saving can be achieved.

[0004]

The thermal head 6 for erasing a visible image recorded on the reversible thermosensitive recording medium 1 as described above.
When repeatedly erasing, the reversible thermosensitive recording medium 1 is moved while the erasing thermosensitive head 6 is in contact with the surface of the reversible thermosensitive recording medium 1.
Dust, fingerprints, and other stains that have adhered to the surface of the device will adhere to the surface of the erasing thermal head 6. When dust or dirt adheres to the surface of the erasing thermal head 6 in this way, the thermal resistance between the erasing thermal head 6 and the reversible thermosensitive recording medium 1 becomes large, so that the reversible thermosensitive recording medium 1 is moving. The amount of heat applied is reduced to cause defective erasure locally, making it impossible to accurately record a new visible image.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a recording method and a recording apparatus capable of stably repeating recording and erasing.

[0006]

According to a recording method of the present invention, recording and erasing are performed in a display area of a reversible thermosensitive recording medium having a display area and a printing area by using a recording head and an erasing thermal head. The repetitive recording method is characterized in that the visible image displayed in the display area is erased by bringing the erasing thermal head into contact with the print area in front of the display area of the reversible thermosensitive recording medium.

It is desirable that the contact of the erasing thermal recording head is released after the display area of the reversible thermosensitive recording medium passes through the erasing thermal recording head and enters a certain area in the printing area after the display area.

It is preferable to set the temperature when the erasing thermal head is in contact with the print area to a temperature lower than the erasing temperature when it is in contact with the display area.

Further, the surface roughness of the above-mentioned printing area is preferably set in the range of 2 μm to 15 μm at the maximum height.

A recording apparatus according to the present invention has a recording head and a thermal recording head for erasing, and repeatedly records and erases a visible image in a display area of a reversible thermosensitive recording medium having a display area and a printing area. The apparatus has a heating area selection means and a thermal head driving means, and the heating area selection means is transported.
It has a certain length from the display area of the reversible thermosensitive recording medium.
Touch the erasing thermal head from the print area in front of the
The print area passes through the erasing thermal head and then
After passing the erasing thermal head for a fixed length, erasing thermal sensitivity
It is characterized in that the timing for releasing the contact of the head is selected, and the thermal head driving means brings the erasing thermal head into contact with the reversible thermosensitive recording medium at the timing selected by the heating area selecting means to release the contact.

It is desirable that the heating area selecting means selects a range in which the thermal head for erasing contacts the reversible thermosensitive recording medium at least 5 mm in the printing areas before and after the display area.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a reversible thermosensitive recording medium having a display area and a printing area is heated in a recording device which repeats recording and erasing by using a recording head and an erasing thermal head. Area selecting means and heating head driving means are provided. When the visible image recorded in the display area of the reversible thermosensitive recording medium is erased and a new visible image is recorded, the heating area selection means includes a certain range of the print area before or after the display area. Select the heating area. The erasing thermal head is brought into contact with the selected heating area of the reversible thermal recording medium by the heating head driving means, and the erasing thermal head is rubbed by the friction between the printing area having a surface roughness larger than the display area and the erasing thermal head. The adhered dust and dirt are removed, and then the erasing thermal head is brought into contact with the display area to reduce the thermal resistance between the erasing thermal head and the display area to uniformly heat the display area.

When the erasing thermal head is brought into contact with the printing area and the display area, the temperature when the erasing thermal head is in contact with the printing area is lower than the erasing temperature when the erasing thermal head is in contact with the display area. The temperature is set to prevent fouling such as dust from fusing and make it easier to remove the fouling.

By making the contact area between the erasing thermal head and the printing area at least 5 mm or more, the efficiency of removing dust and the like adhering to the erasing thermal head is increased, and the number of times of reliable erasing can be increased.

Further, the surface roughness of the print area is set to 2 μm R _MAX or more, which is larger than that of the display area, to reliably remove dust and the like adhering to the erasing thermal head. Further, when the surface roughness of the printing region is set to 15 μm R _MAX or less and repeatedly used, it is prevented that the surface of the erasing thermal head or the recording head is scratched or worn.

[0016]

1 is a layout view showing the structure of an embodiment of the present invention. As shown in the figure, a recording device 2 for recording and erasing the reversible thermosensitive recording medium 1 has a plurality of conveying rollers 3 and a plurality of platen rollers 4 along a conveying path of the reversible thermosensitive recording medium 1. A thermal head 5, a thermal erasing head 6 and a magnetic head 7 are arranged in order from a recording medium insertion port 8. As shown in the front view of FIG. 2, the reversible thermosensitive recording medium 1 has a display area 1b for recording and displaying a visible image in the center of a printing area 1a on which various information is printed. Display area 1
As shown in FIG. 6, b is a recording layer composed of a polymer / low molecular composite type recording material in which an organic low molecular substance 33 is dispersed in a polymer 32 on a base film 31 made of polyester film or the like. 34 is provided and the recording layer 34 is protected by the overcoat layer 35 so that recording and erasing of a visible image can be repeated. The thermal head 5 records a visible image on the reversible thermosensitive recording medium 1. As shown in the cross-sectional view of FIG. 3, the erasing thermal head 6 is formed on a ceramic substrate 9 having a thickness of 1 mm, for example, and has a width of 2 mm and a thickness perpendicular to the transport path of the reversible thermosensitive recording medium 1. Saga 20
μm band-shaped film-shaped heating resistor 10 and film-shaped heating resistor 1
A protective film 11 made of crystallized glass that covers 0, and a protective film 1 is formed by applying a pulse current to the film-shaped heating resistor 10.
The surface of No. 1 is heated to a constant temperature, and the reversible thermosensitive recording medium 1
The visible image recorded in the display area 1b is erased. An initial position detection sensor 12 is provided at the rear stage of the transport roller 3 provided near the recording medium insertion port 8, and an inversion detection sensor 13 is provided at the rear stage of the erasing thermal head 6.

As shown in the block diagram of FIG. 4, the control section of the recording apparatus 1 instructs the main control section 21 for controlling the operation of the entire apparatus and recording / erasing on the reversible thermosensitive recording medium 1 and the display area. The operation display unit 22 for instructing 1b and displaying the operating state, the input unit 23, the storage unit 24, the transport control unit 25, the print control unit 26, the erasing control unit 27, the heating area selection unit 28, the heating head drive unit 29. And read control unit 30
Have. The input unit 23 inputs information to be recorded on the reversible thermosensitive recording medium 1 and stores it in the storage unit 24. In the storage unit 24, as shown in FIG. 2, for example, a range L ₁ and positions L ₂ and L ₃ of the display area 1b of the reversible thermosensitive recording medium 1 are set. The transport control unit 25 drives the transport motor 14 that drives each of the transport rollers 3 and controls forward rotation and reverse rotation. The print controller 26 controls the recording operation of the thermal head 5. The erasing control unit 27 controls the current flowing through the erasing thermal head 6 to control the head surface temperature. The heating area selection unit 28 is the reversible thermosensitive recording medium 1 previously stored in the storage unit 24.
The erasing thermal head 6 is brought into contact with the reversible thermosensitive recording medium 1 in accordance with the range and position of the display area 1b of the reversible thermosensitive recording medium 1 or the range and position of the display area 1b of the reversible thermosensitive recording medium 1 designated by the operation display unit 22. Select timing and contact time range.
The thermal head drive unit 29 brings the erasing thermal head 6 into contact with the reversible thermosensitive recording medium 1 at the timing and the contact time range selected by the heating region selection unit 28, and heats the reversible thermosensitive recording medium 1. The reading control unit 30 controls the reading operation of the magnetic head 7.

The operation of erasing the visible image recorded in the display area 1b of the reversible thermosensitive recording medium 1 by the recording device 2 configured as described above and recording new information as a visible image is shown in FIG. This will be described with reference to the time chart.

The reversible thermosensitive recording medium 1 has a recording medium insertion port 8
When recording and erasing are instructed from the operation display unit 22 when set to, the main control unit 21 instructs the transport control unit 25 to transport the reversible thermosensitive recording medium 1. When the conveyance control unit 25 is instructed to convey the reversible thermosensitive recording medium 1, the conveyance controller 14 drives the conveyance motor 14 in the normal direction at a constant speed. The transport roller 3 is rotated by driving the transport motor 14 to transport the set reversible thermosensitive recording medium 1 along the thermal head 5, the erasing thermal head 6 and the magnetic head 7. Reversible thermosensitive recording medium 1
When the reverse end of the reversible thermosensitive recording medium 1 is detected by the reversal detection sensor 13, the conveyance control unit 25 reverses the conveyance motor 14 at a predetermined constant timing t _3. The reversible thermosensitive recording medium 1 is conveyed to the recording medium insertion port 8 side by reversing the rotation of the conveying roller 3, and the reversible thermosensitive recording medium 1 is reciprocated. While reciprocating the reversible thermosensitive recording medium 1, the reversible thermosensitive recording medium 1 is heated by the erasing thermosensitive head 6 to erase the visible image recorded in the display area 1b, and the thermal head. 5
To record new information as a visible image.

In this way, the conveyance of the reversible thermosensitive recording medium 1 is started, and when the initial position detection sensor 12 detects the leading end of the reversible thermosensitive recording medium 1, the erasing control section 27 applies a current to the erasing thermal head 6. And the erasing thermal head 6 is heated to a constant temperature. At the same time, the heating area selection unit 28 sets the distance L between the initial position detection sensor 12 and the erasing thermal head 6
And a distance (L + L ₂ −) obtained by subtracting a predetermined fixed length L ₀ , for example, 5 mm from the sum (L + L ₂ ) of the length L ₂ from the tip of the reversible thermosensitive recording medium 1 to the display area 1 b.
L ₀ ) and the transport speed v of the reversible thermosensitive recording medium 1 is used to calculate the forward heating start timing t ₁ of the reversible thermosensitive recording medium 1, and a constant length 2L ₀ is added to the length L ₁ of the display area 1b.
The time t ₂ during which the reversible thermosensitive recording medium 1 is heated is calculated from the obtained length (L1 + 2L ₀ ) and the transport speed v of the reversible thermosensitive recording medium 1 and sent to the thermal head drive unit 29. The thermal head driving unit 29 detects the leading edge of the reversible thermosensitive recording medium 1 by the initial position detection sensor 12 and then starts heating t ₁
When the elapsed time has passed, the reversible thermosensitive recording medium 1 is brought into contact with the reversible thermosensitive recording medium 1 which is being conveyed.
Is preheated to raise the temperature of the reversible thermosensitive recording medium 1 to near the clearing temperature. The thermal head drive unit 29 releases the contact of the erasing thermal head 6 with the reversible thermosensitive recording medium 1 when time t ₂ has elapsed after the erasing thermal head 6 was brought into contact with the reversible thermal recording medium 1.

When the preheating is performed in this manner, the display area 1
Since the erasing thermal head 6 is brought into contact with the erasing thermal head 6 from the printing area 1a which is a certain length L ₀ before b, dust attached to the surface of the erasing thermal head 6 in the printing area 1a having a larger surface roughness than the display area 1b. And dirt can be removed. Further, since the display area 1b of the reversible thermosensitive recording medium 1 passes the erasing thermal head 6 and then the erasing thermal head 6 contacts the printing area 1a for a certain length L ₀ and then releases the contact, the erasing is performed. It is also possible to remove dust and dirt attached when the thermal head 6 contacts the display area 1b and heats it.

This preheated reversible thermosensitive recording medium 1
When the rear end of the reversible thermosensitive recording medium 1 is detected by the reversal detection sensor 13 again after the rear end passes through the position of the reversal detection sensor 13 and the moving direction is reversed, the heating area selector 28 reverses. A predetermined fixed length L ₀ is calculated from the sum of the distance L _R between the detection sensor 13 and the erasing thermal head 6 and the length L ₃ from the rear end of the reversible thermosensitive recording medium 1 to the display area 1b.
The distance obtained by subtracting the length of _{(L R + L 3 -L 0} ) and calculates the return of the heating start timing t ₄ of the reversible thermosensitive recording medium 1 from the conveying speed v of the reversible thermosensitive recording medium 1, and the display region 1b L ₁ plus a fixed length 2 L ₀ (L ₁ +2
The time t ₅ during which the reversible thermosensitive recording medium 1 is heated is calculated from L ₀ ) and the transport speed v of the reversible thermosensitive recording medium 1 and sent to the thermal head drive unit 29. The thermal head drive unit 29 sets the erasing thermal head 6 to the reversible thermal recording medium when the backward heating start timing t ₄ has elapsed after the reverse path of the reversible thermal recording medium 1 was detected by the reversal detection sensor 13. The reversible thermosensitive recording medium 1 is heated by bringing it into contact with 1 to raise the temperature of the reversible thermosensitive recording medium 1 to the clearing temperature. The thermal head drive unit 29 releases the contact of the erasing thermal head 6 with the reversible thermosensitive recording medium 1 after a time t ₅ has elapsed since the erasing thermal head 6 was brought into contact with the reversible thermal recording medium 1.

In this way, the visible image stored in the reversible thermosensitive recording medium 1 can be surely erased by preheating the display area 1b by the erasing thermal head 6 and then heating it to the clearing temperature. it can.

On the other hand, when the transport motor 15 is reversed and the moving direction of the reversible thermosensitive recording medium 1 is reversed, and the rear end of the reversible thermosensitive recording medium 1 is detected by the reversal detection sensor 13, print control is performed. The section 26 starts the printing operation of the thermal head 5 at a print timing t ₆ preset according to the moving speed of the reversible thermosensitive recording medium 1 and displays new information in the display area 1b of the reversible thermosensitive recording medium 1. Record the visible image shown.
When the reversible thermosensitive recording medium 1 on which the new visible image is recorded is ejected from the recording medium insertion port 8, the visible image on the reversible thermosensitive recording medium 1 is erased and the recording operation of the new visible image is completed. To do.

As described above, the length L _{0 of} contact of the erasing thermal head 6 with the printing area 1a of the reversible thermosensitive recording medium 1 is changed, and the erasing and recording of the display area 1b are repeated, and the number of times the erasing failure occurs. The following table shows the results of the investigation.

[0026]

[Table 1]

As shown in the above table, the erasing thermal head 6
When only the display area 1b of the reversible thermosensitive recording medium 1 is contacted, dust and the like adhere to the surface of the erasing thermosensitive head 6 every time erasing is repeated, and the thermal resistance between the reversible thermosensitive recording medium 1 and Became large, and an erasing failure occurred only by repeating the erasing 10 times, but the printing area 1a on the front side of the display area 1b
When the thermal head 6 for erasing is brought into contact with 5 mm, the erasing failure occurs when the erasing is repeated 55 times, and the display area 1
The thermal head 6 for erasing is 5 mm in the printing area 1a on both sides of b.
When they were contacted with each other, erasing failure occurred when erasing was repeated 102 times. Further, the erasing thermal heads 6 were brought into contact with the print area 1a on both sides of the display area 1b by 15 mm.
In this case, the erasing failure occurred only after the erasing was repeated 222 times. As a result, when the erasing thermal head 6 is brought into contact with the printing area 1a for at least 5 mm, erasing can be repeated about 50 times without cleaning the erasing thermal head 6. Further, by increasing the range in which the erasing thermal head 6 is in contact with the printing area 1a, it is possible to increase the number of times the visible image can be reliably erased repeatedly.

Further, the number of repetitions that the visible image can be surely erased differs depending on the surface roughness of the printing area 1a. If the maximum height of the surface roughness is small, the removal efficiency of dust and the like is lowered and the surface roughness is reduced. If the maximum height is large, the efficiency of removing dust will increase. However, if the maximum height of the surface roughness is too large, the frictional force with the surface of the erasing thermal head 6 or the thermal head 5 becomes large, and the erasing thermal head 6 or the erasing thermal head 6 may be repeatedly erased and recorded. The surface coefficient of the thermal head 5 may be worn or the surface of the printing area 1a may be scraped off, causing dust. Therefore the surface roughness the surface roughness of the display area 1b of the printing region 1a, for example in a range from 15MyumR _MAX from greater 2MyumR _MAX than 0.8MyumR _MAX was optimal.

The above embodiment is based on the reversible thermosensitive recording medium 1.
Although a case where a new visible image is recorded after the recorded visible image is reciprocally moved by reciprocating the head has been described, the erasing thermal head 6 is provided on the upstream side of the thermal head 5, and the reversible thermal recording medium is provided. The same can be applied to the case where 1 is moved in only one direction.

In the above embodiment, the temperature when the erasing thermal head 6 is in contact with the printing area 1a and the display area 1b is constant temperature, that is, the erasing temperature is heated. By setting the temperature when the thermal head 6 is in contact with the print area 1a to be lower than the erasing temperature when it is in contact with the display area 1b, it is possible to prevent dirt such as dust from fusing. It is possible to remove dirt more easily.

[0031]

As described above, according to the present invention, when recording and erasing are repeated using a recording head and an erasing thermal head in a display area of a reversible thermosensitive recording medium having a display area and a printing area. , Select a heating area including a certain range of the printing area before or after the display area, and bring the erasing thermal head into contact with the heating area of the selected reversible thermosensitive recording medium, so that the surface roughness is larger than that of the display area. The friction between the printing area and the erasing thermal head removes dust and dirt from the erasing thermal head, and then the erasing thermal head is brought into contact with the display area. The resistance can be reduced, the display area can be uniformly heated, and the recorded visible image can be surely erased.

Further, by setting the temperature when the erasing thermal head is in contact with the printing area to a temperature lower than the erasing temperature when it is in contact with the display area, dirt such as dust is fused. Can be prevented and the efficiency of removing dirt can be improved.

By setting the contact area between the erasing thermal head and the printing area to be at least 5 mm or more, the efficiency of removing dust and the like adhering to the erasing thermal head can be increased, and the number of times of reliable erasing can be increased.

Further, when the surface roughness of the printing area is set to 2 μm R _MAX or more, which is larger than that of the display area, dust and the like adhering to the erasing thermal head is surely removed , and the surface roughness of the printing area is 15 μm RMAX or less when repeatedly used. It is possible to prevent the surface of the erasing thermal head or the recording head from being scratched or abraded, and to stably repeat erasing and recording.

[Brief description of drawings]

FIG. 1 is a layout diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a front view of a reversible thermosensitive recording medium.

FIG. 3 is a sectional view showing an erasing thermal head.

FIG. 4 is a block diagram showing a configuration of a control unit of the above embodiment.

FIG. 5 is a time chart showing the operation of the above embodiment.

FIG. 6 is a cross-sectional view showing the structure of a reversible thermosensitive recording medium.

FIG. 7 is a temperature-transmittance characteristic diagram showing reversible characteristics of a reversible thermosensitive recording medium.

FIG. 8 is a layout diagram showing a configuration of a conventional example.

[Explanation of symbols]

1 Reversible thermosensitive recording medium 3 Transport roller 5 thermal head 6 Thermal head for erasing 12 Initial position detection sensor 13 Inversion detection sensor 21 Main controller 28 Heating area selector 29 Thermal head drive

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Claims (6)

(57) [Claims] 1. A reversible thermosensitive recording method for recording and erasing a visible image by using a recording head and an erasing thermal head in a display area of a reversible thermosensitive recording medium having a display area and a printing area. A recording method characterized in that a visible image displayed in the display area is erased by bringing the erasing thermal head into contact with the print area in front of the display area of the recording medium. 2. The contact of the erasing thermal head is released after the display area of the reversible thermosensitive recording medium passes through the erasing thermal head and enters a certain range in the printing area after the display area. Recording method. 3. The recording method according to claim 1, wherein the temperature when the erasing thermal head is in contact with the printing area is set to be lower than the erasing temperature when it is in contact with the display area. 4. The surface roughness of the printed area is 2 at the maximum height.
The recording method according to claim 3, wherein the recording layer has a thickness in the range of 15 to 15 μm. 5. A recording device, comprising a recording head and an erasing thermal head, which repeats recording and erasing on a reversible thermosensitive recording medium having a display area and a printing area, wherein a heating area selecting means and a thermal head driving means are provided. And the heating area selection means is a table of the reversible thermosensitive recording medium being conveyed.
Sensitive for erasing from the print area in front of the display area by a certain length
Touch the head so that the display area passes through the erasing thermal head
Then pass the erasing thermal head for a certain length of the print area.
Select the timing for releasing the contact of the erasing thermal head, and the thermal head driving means brings the erasing thermal head into contact with the reversible thermal recording medium at the timing selected by the heating area selecting means. , A recording device characterized by releasing the contact. 6. The recording apparatus according to claim 5, wherein the heating area selecting means selects a range in which the erasing thermal head contacts the reversible thermosensitive recording medium at least 5 mm in a printing area before and after the display area.