JPH0596767A - Recording device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object to provide a recording apparatus which forms recording and erasing with high visibility on a recording material. In a recording device for recording and erasing a visible image by applying thermal energy, an applying unit for applying thermal energy to a storage medium and a thermal energy by the applying unit for recording and erasing a visible image. The recording unit and the erasing unit are provided with the same number of times, respectively, and a control unit for giving a longer time during recording than during erasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording and erasing on a recording material capable of repeatedly displaying and erasing a visible image by heat.

[0002]

2. Description of the Related Art In the conventional hard copy recording, an image is formed on a recording medium such as paper from the outside with a developing material such as ink or toner, or a recording layer is formed on a base material such as thermal recording paper. Was provided and a permanent image was recorded by forming a visible image on this recording layer. However, with the construction of various network networks and the spread of facsimiles and copying machines, the rapid increase in the consumption of these recording materials has caused problems of nature destruction such as deforestation and social problems such as garbage disposal. In order to deal with these problems, it is strongly required to reduce the consumption of recording material such as reproduction of recording paper. For this problem, a recording material that can be repeatedly recorded / erased has attracted attention.

As a material having such characteristics, there has been proposed a recording material capable of reversibly changing both transparent and opaque states depending on the temperature applied to the recording material (Japanese Patent Laid-Open No. 55-1).
54198). When the temperature of the recording material is increased from T ₁ to T ₂ in the cloudy state, the recording material changes from the cloudy state to the transparent state and maintains the transparent state as it is even when the temperature returns to T ₁ . Then, the temperature of the recording material is raised to T ₃ beyond the T ₂ from T _1, becomes opaque goes from clear again returned to T _1, holding as it opaque state.
This change can be repeatedly reproduced. A study on deterioration of resolution when repetitive recording with a thermal head using such a recording material is reported (Proceedings of the 4th Non-Impact Printing Technology Symposium,
3-2, p57 (1987)). Further, a display changing device for displaying and erasing a display body having a thermoreversible recording material has been proposed (Japanese Utility Model Laid-Open No. 19568/1990). In this device, erasing means for thermally erasing the display of the display body,
A configuration in which a printing means for thermally printing is provided, and as a specific example, the thermoreversible display of a floppy disk cartridge is erased by a heater head (erasing means), and a display is written by using a moving thermal head (printing means). It is shown. Further, there is disclosed a device for erasing and recording a display by using a heat roller (erasing means) and a thermal head (printing means) on an information recording card having a thermoreversible recording layer (Japanese Utility Model Laid-Open No. 2-3876). .. Also, a recording material using a leuco dye as a color source, which gives a reversible color tone change only by controlling thermal energy, has been announced (Jpn.
Hardcopy '90, NIP-2, p147 (1
990)).

[0004]

However, in the conventional repetitive recording, erasable recording material recording and erasing method or apparatus, since the recording means and the erasing means are respectively provided, the apparatus becomes large in size. There is a point, and it has become possible to perform recording and erasing by the same means. However, in the case of recording and erasing by the same means, the thermal energy applied to the storage medium at the time of recording by the recording means and the thermal energy applied to the storage means at the time of erasing by the erasing means are different, There is a problem that recording and erasing with high visibility cannot be performed because erasing by the erasing means is insufficient because the time for applying heat energy to the storage medium is different. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus that forms recording and erasing with high visibility on a recording material.

[0005]

In order to solve the above problems, the present invention provides a visible image by applying heat energy to a storage medium in which a visible image is recorded and erased by applying heat energy. In a recording device for recording and erasing an image, an applying unit for applying thermal energy to a storage medium for recording and erasing a visible image, and recording and erasing the thermal energy by the applying unit for recording and erasing the visible image. An erasing unit is provided with an application control means for applying the same number of times and a longer time during recording than during erasing.

[0006]

By using the recording method of the present invention, a new visible image can be overwritten on the visible image already formed on the recording material. Moreover, recording and erasing can be performed by one energy applying means.

[0007]

EXAMPLE FIG. 1 shows an energizing pulse of the thermal head in one example of the present invention. 1A shows energizing pulses when the pulse train records dots, and when the pulse train shown in FIG. 1B erases dots. In the recording method according to the present invention, a plurality of energizing pulses are provided within one dot formation period to drive and heat the thermal head heating resistor, and the thermal head heating resistor is brought into contact with the heating resistor to record image information on the recording medium.
In the conventional thermal recording medium, for example, thermal recording paper or thermal transfer recording ribbon, recording can be performed by heating at a temperature higher than a threshold temperature at which color change or state change such as softening, melting, and sublimation occurs. The recording medium used has two threshold temperatures of erasing and recording, and requires three-valued temperature control, which is a characteristic that conventional thermal recording media do not have.

The voltage applied to the thermal head is kept constant, the energization time / pulse period ratio value of each pulse is increased during recording to reduce the pulse interval, and the energization time / period ratio value of each pulse during erasing. To increase the pulse interval to control the heating element temperature of the thermal head. In the present embodiment, a heating resistor having an average resistance value of 600Ω has a pulse number of 8 in one dot formation period for both recording and erasing, an energization time / period ratio of 80% during recording, and an energization time / period ratio of erasing. Is set to 50% and 10 V is applied to heat the heating resistors to different temperatures.

The recording and erasing operations by the energizing pulse shown in FIG. 1 will be described in detail with reference to FIG. Figure 2
FIG. 2A shows each energization pulse train at the time of recording and erasing.
FIG. 2B shows the time change of the heat generation temperature of the thermal head heating resistor at that time, and FIG. 2C shows the time change of the temperature of the recording medium at that time. When the energizing pulse is applied not in a continuous manner but in a divided manner, the temperature profile of the heating resistor gradually rises due to the balance between heat storage and heat radiation in the vicinity of the heating resistor, as shown in FIG. 2B. Reach temperature range. The recording layer temperature profile of the recording medium is also shown in FIG.
As shown in, it rises slowly and reaches the target temperature range.

In the recording system according to the present invention, the heat generation and heat dissipation balance of the heat generating resistor and the heat dissipation and heat dissipation balance of the recording medium are changed by changing the energization time / period ratio of the energization pulse during recording and during erasing. The feature is that the maximum temperature of the recording medium is controlled by changing it during recording and erasing.

Further, by using the same number of energizing pulses during recording and erasing as in the embodiment, the heating time during recording and erasing are the same, and the recording medium has almost the same recording temperature and erasing temperature. Can be held for hours.

FIG. 3 shows an example of overwrite recording when the recording method of the present invention is used, and the case of overwriting the character "L" from the character "I" will be described. First, as shown in FIG. 3A, the character "I" is recorded on the rewritable recording medium. In the case of overwriting recording of the character "L" on it, the process of FIG. A heating resistor array: 2 of a thermal head (not shown) is in contact with the rewritable recording medium: 1, and the array of heating resistors is arranged to be perpendicular to the recording direction. The heating resistors are provided in a sufficient number to record the width of the rewritable recording medium. 3 is a part of the image "I" which has been already recorded, and 4 is a part of the image "L" which is currently being recorded. 5 is a part of the erased image "I", and 6 is a re-recorded part. When recording on a rewritable recording medium, it is sufficient to raise the heating resistor corresponding to the pixel of interest: mark dot to a temperature at which the recording medium rises to the cloudy temperature range regardless of the existing image. Regardless of the existing image, the pixel of interest: the heating resistor corresponding to the space dot may be raised to a temperature at which the recording medium rises to the transparent temperature range. In this way, while the rewritable recording medium is conveyed in the direction of the arrow under the heating resistor array of the fixed thermal head, the heating resistor is selectively heated by the recording method according to the present invention, so that a new image: 4 The so-called overwrite recording is realized, in which the old image: 3 is erased at the same time that the image is recorded. The recording layer of the rewritable recording medium used here becomes transparent at about 70 to 100 ° C., and the cloudiness becomes saturated at about 110 ° C. or higher. The upper limit of the heating temperature is determined by the heat resistance of the protective layer or recording layer. This recording medium had a temperature of about 160 ° C.

In the above description, the energization time to the heating resistor is simply divided into two types in order to set the temperature of the recording layer to the cloudy temperature range or the erasing temperature range, but in reality, thermal recording by the thermal head is performed. It is known that the temperature profile of the heating resistor is not necessarily the same even if the energization time is the same depending on the heat storage of the thermal head, the heat generation history, the environment, and the like. In this rewritable recording, it is important to give energy to the recording material so that the recording layer temperature becomes the cloudy temperature range or the transparent temperature range regardless of the heat storage, the heat generation history, the environment and the like. Therefore, by controlling the applied energy in consideration of these factors, the recording layer temperature can be raised to a predetermined temperature more accurately.

The control of applied energy in the present invention will be described in detail with reference to FIG. Image data recorded is 1
It is serially transferred line by line and is input to the reference area cutout unit 7. The reference area cutout unit 7 cuts out a portion of the line data corresponding to the reference area around the target pixel and outputs the cutout portion to the mark dot / space dot determination unit 8, the heat storage amount calculation unit 9, and the data update unit 10. The mark dot / space dot determination unit 8 determines whether the pixel of interest is a mark dot that forms an image or a space dot that does not form an image. The line buffer 11 has a capacity corresponding to the number of lines corresponding to the reference area, and the data updating unit 10 sequentially replaces the image data therein. Image data corresponding to the reference region from the reference region cutout unit 7 and the line buffer 11 is input to the heat storage amount calculation unit 9, and heat storage for the target pixel is performed using a preset weighting table or the like as shown in FIG. Calculate the amount. In the recording / erasing energy calculation unit 12, mark dots /
The amount of energy applied to the pixel of interest is calculated from the output from the space dot determination unit 8, and from the output from the heat storage amount calculation unit 9,
The amount of applied energy described above is corrected. The corrected data of the applied energy amount is sent to the recording / erasing unit, and recording / erasing is performed by the thermal head.

A feature of this recording system is that not only the mark data forming an image is energized, but also space data not forming an image is energized. For this purpose, the heat storage amount calculation section is provided with tables for mark data and space data. A method of obtaining the heat storage amount for the target pixel using the weighting table in the heat storage amount calculation unit will be described. FIG. 5A shows image data corresponding to the weighting table, and FIG. 5B shows an example of the weighting table. In this embodiment, (3 dots × 3
(Dot) size weighting table is used. For example, for an element having M: -0.3 and S: -0.1, the image data corresponding to the element is a mark dot forming an image. In this case, the weight value is -0.3, and in the case of space dots that do not form an image, the weight value is -0.1, and the smaller the value, the larger the heat storage amount. By adding the weight values of all the image data in the reference area, it is possible to calculate the micro heat storage amount near the target pixel. The element corresponding to the pixel of interest is
M: 8 and S: 8, which correspond to the basic energization time of mark dots and space dots,
The value obtained by adding the weight of each element to these values becomes the energization time of this pixel of interest.

Thus, by correcting the number of energizing pulses for different heat storage energies in each heating resistor, the recording layer temperature of the rewritable recording medium is irrespective of the image pattern, and the cloudiness temperature in the case of mark data. It can be set to the temperature range or the transparent temperature range for space data.

When the above correction is performed, in the embodiment shown in FIG. 2, since the same number of energizing pulses are used during recording and erasing, the same level control may be performed during recording and erasing. it can. That is, referring to FIG. 2, during recording,
At the time of erasing, 3 to 4 pulses are included in each state change temperature range. Therefore, it is possible to perform correction within the range of the same number of pulses (recording: 4 pulses, erasing 3 pulses) during recording and erasing. On the other hand, recording with a plurality of energizing pulses provided in the same 1-dot formation cycle
Even in the erasing recording method, the energization time / period ratio of the energizing pulse is constant during recording and erasing, and the method of recording and erasing by changing the number of pulses, the erasing requires less pulses than recording. The recording medium must be heated. Therefore, when the above-mentioned correction is required, the number of pulses that can be used for correction in the necessary temperature range during erasing is smaller than that during recording, and the same level of control cannot be performed.

Another embodiment will be described with reference to FIG. In this embodiment, a recording energizing pulse train for forming a visible image and an erasing energizing pulse train for erasing a visible image are provided within one dot forming cycle, and this is selected according to recording data and given to a heating resistor. To use. In order to realize this, the energizing pulse train as shown in FIG. 6A is applied to the thermal head. Ten pulses having a conduction time / cycle ratio of 50% provided in the first half of one dot formation cycle of this conduction pulse train correspond to the erase pulse, and the latter half 1 /
The ten pulses having the energization time / period ratio of 80% provided in No. 2 correspond to the recording pulses. When actually recording, the recording data 0000000 as shown in FIG.
By giving 0001111111100, a recording energizing pulse as shown in FIG. 6C is created. Similarly, when erasing is performed, erased data 11111 as shown in FIG.
Given 11000000000000, FIG. 6 (5)
Make an erase energizing pulse like.

If the total of the energizing time / cycle of the recording pulse and the energizing time / cycle of the erasing pulse may be less than 100%, the pulse train shown in FIG. Independence of energization time / period ratio can be easily realized.

In the above embodiments, the white turbid state of the recording layer is used as the recorded image, but the white turbid state may be used as the initial state and the transparent state may be used as the recorded image. Further, the recording material to which the present invention can be applied is not limited to the material of the embodiment, and can be applied to a recording material using a leuco dye as a color-forming source which gives a reversible color tone change only by controlling thermal energy.

According to the present invention, the image can be rewritten without erasing the already recorded image in advance.
In addition, since the energizing pulses for recording and erasing are independent, recording and erasing of an image can be stably performed regardless of the image pattern. Also, since the same number of energizing pulse trains can be used,
In recording and erasing, the same level of control can be performed on the correction for heat accumulation. Furthermore, image recording and image erasing can be performed by the same means, which makes the device compact and
It can be simplified. It has become possible to record and erase on a pixel-by-pixel basis in any part of the recording material.

[0022]

As described above, according to the recording apparatus of the present invention, highly visible recording and erasing can be formed on the recording material.

[Brief description of drawings]

FIG. 1 is a diagram showing an energization pulse train for a heating resistor of a thermal head according to an embodiment of the present invention.

FIG. 2 is a diagram showing a temperature change of a recording medium when recording and erasing are performed by the recording method of the present invention.

FIG. 3 is a diagram showing an example of overwrite recording when the recording method of the present invention is used.

FIG. 4 is a diagram for explaining an applied energy control unit used in an example.

FIG. 5 is a diagram for explaining a weighting table.

FIG. 6 is a diagram showing a second embodiment of recording pulses given in the present invention.

FIG. 7 is a diagram showing a third embodiment of recording pulses applied in the present invention.

[Explanation of symbols]

7 reference area cutout unit, 9 heat storage amount calculation unit, 1
2 Recording / erasing energy calculator

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display part 8305-2H B41M 5/26 P

Claims (2)

[Claims] 1. A recording apparatus for recording and erasing a visible image by applying thermal energy to a storage medium, wherein a visible image is recorded and erased by applying thermal energy. Applying means for applying thermal energy to the storage medium for erasing, and the thermal energy by the applying means is equal to the recording and erasing units in the recording and erasing of the visible image, respectively. A recording apparatus, further comprising: an application control unit that provides an application for a long time. 2. A recording device for recording and erasing a visible image by applying thermal energy to a storage medium, wherein a visible image is recorded and erased by applying thermal energy. First generating means for generating a thermal energy signal for applying thermal energy to the storage medium for erasing, and second generating means for generating a recording signal for recording and erasing the visible image And a control means for controlling the heat energy applied to the storage medium based on the heat energy signal and the recording signal means.